Update luajit crate docs

Refactor and overhaul luajit crate
Add basic timing library
2025-06-30 06:24:37 +10:00 · 2025-06-30 05:59:54 +10:00 · 2025-06-29 18:06:56 +10:00 · 2025-06-29 17:58:34 +10:00 · 2025-06-29 17:48:56 +10:00 · 2025-06-28 21:31:42 +10:00
45 changed files with 5143 additions and 1963 deletions
--- a/.luarc.json
+++ b/.luarc.json
@@ -1,5 +1,9 @@
 {
  "$schema": "https://raw.githubusercontent.com/LuaLS/vscode-lua/master/setting/schema.json",
  "runtime.version": "LuaJIT",
-  "diagnostics.disable": ["redefined-local", "lowercase-global"]
+  "diagnostics.disable": [
+    "undefined-global",
+    "redefined-local",
+    "lowercase-global"
+  ]
 }
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -534,6 +534,12 @@ dependencies = [
 "unicode-xid",
 ]

+[[package]]
+name = "diff"
+version = "0.1.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "56254986775e3233ffa9c4d7d3faaf6d36a2c09d30b20687e9f88bc8bafc16c8"
+
 [[package]]
 name = "displaydoc"
 version = "0.2.5"
@@ -573,6 +579,12 @@ dependencies = [
 "windows-sys 0.60.2",
 ]

+[[package]]
+name = "fastrand"
+version = "2.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "37909eebbb50d72f9059c3b6d82c0463f2ff062c9e95845c43a6c9c0355411be"
+
 [[package]]
 name = "flate2"
 version = "1.1.2"
@@ -685,6 +697,19 @@ version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a8d1add55171497b4705a648c6b583acafb01d58050a51727785f0b2c8e0a2b2"

+[[package]]
+name = "globset"
+version = "0.4.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "54a1028dfc5f5df5da8a56a73e6c153c9a9708ec57232470703592a3f18e49f5"
+dependencies = [
+ "aho-corasick",
+ "bstr",
+ "log",
+ "regex-automata 0.4.9",
+ "regex-syntax 0.8.5",
+]
+
 [[package]]
 name = "h2"
 version = "0.4.10"
@@ -1025,14 +1050,16 @@ checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
 name = "lb"
 version = "0.0.1"
 dependencies = [
- "camino",
 "derive_more",
+ "globset",
 "luaffi",
 "luaify",
 "luajit",
 "sysexits",
+ "tempfile",
+ "thiserror",
 "tokio",
- "tracing",
+ "walkdir",
 ]

 [[package]]
@@ -1097,16 +1124,6 @@ version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "241eaef5fd12c88705a01fc1066c48c4b36e0dd4377dcdc7ec3942cea7a69956"

-[[package]]
-name = "lock_api"
-version = "0.4.13"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "96936507f153605bddfcda068dd804796c84324ed2510809e5b2a624c81da765"
-dependencies = [
- "autocfg",
- "scopeguard",
-]
-
 [[package]]
 name = "log"
 version = "0.4.27"
@@ -1138,6 +1155,7 @@ dependencies = [
 name = "luaify"
 version = "0.0.1"
 dependencies = [
+ "pretty_assertions",
 "proc-macro2",
 "quote",
 "syn",
@@ -1151,7 +1169,6 @@ dependencies = [
 "bstr",
 "luaffi",
 "luajit-sys",
- "thiserror",
 ]

 [[package]]
@@ -1319,29 +1336,6 @@ version = "4.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "48dd4f4a2c8405440fd0462561f0e5806bd0f77e86f51c761481bdd4018b545e"

-[[package]]
-name = "parking_lot"
-version = "0.12.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "70d58bf43669b5795d1576d0641cfb6fbb2057bf629506267a92807158584a13"
-dependencies = [
- "lock_api",
- "parking_lot_core",
-]
-
-[[package]]
-name = "parking_lot_core"
-version = "0.9.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bc838d2a56b5b1a6c25f55575dfc605fabb63bb2365f6c2353ef9159aa69e4a5"
-dependencies = [
- "cfg-if",
- "libc",
- "redox_syscall",
- "smallvec",
- "windows-targets 0.52.6",
-]
-
 [[package]]
 name = "percent-encoding"
 version = "2.3.1"
@@ -1410,6 +1404,16 @@ dependencies = [
 "zerocopy",
 ]

+[[package]]
+name = "pretty_assertions"
+version = "1.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3ae130e2f271fbc2ac3a40fb1d07180839cdbbe443c7a27e1e3c13c5cac0116d"
+dependencies = [
+ "diff",
+ "yansi",
+]
+
 [[package]]
 name = "prettyplease"
 version = "0.2.35"
@@ -1506,15 +1510,6 @@ dependencies = [
 "getrandom 0.2.16",
 ]

-[[package]]
-name = "redox_syscall"
-version = "0.5.13"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0d04b7d0ee6b4a0207a0a7adb104d23ecb0b47d6beae7152d0fa34b692b29fd6"
-dependencies = [
- "bitflags",
-]
-
 [[package]]
 name = "regex"
 version = "1.11.1"
@@ -1606,10 +1601,13 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"

 [[package]]
-name = "scopeguard"
-version = "1.2.0"
+name = "same-file"
+version = "1.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
+checksum = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
+dependencies = [
+ "winapi-util",
+]

 [[package]]
 name = "semver"
@@ -1667,15 +1665,6 @@ version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"

-[[package]]
-name = "signal-hook-registry"
-version = "1.4.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9203b8055f63a2a00e2f593bb0510367fe707d7ff1e5c872de2f537b339e5410"
-dependencies = [
- "libc",
-]
-
 [[package]]
 name = "simdutf8"
 version = "0.1.5"
@@ -1750,6 +1739,19 @@ version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "198f60d1f7f003f168507691e42d082df109ef0f05c6fd006e22528371a5f1b4"

+[[package]]
+name = "tempfile"
+version = "3.20.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e8a64e3985349f2441a1a9ef0b853f869006c3855f2cda6862a94d26ebb9d6a1"
+dependencies = [
+ "fastrand",
+ "getrandom 0.3.3",
+ "once_cell",
+ "rustix",
+ "windows-sys 0.59.0",
+]
+
 [[package]]
 name = "thiserror"
 version = "2.0.12"
@@ -1832,9 +1834,7 @@ dependencies = [
 "bytes",
 "libc",
 "mio",
- "parking_lot",
 "pin-project-lite",
- "signal-hook-registry",
 "socket2",
 "tokio-macros",
 "tracing",
@@ -2113,6 +2113,16 @@ dependencies = [
 "rustversion",
 ]

+[[package]]
+name = "walkdir"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29790946404f91d9c5d06f9874efddea1dc06c5efe94541a7d6863108e3a5e4b"
+dependencies = [
+ "same-file",
+ "winapi-util",
+]
+
 [[package]]
 name = "want"
 version = "0.3.1"
@@ -2164,6 +2174,15 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"

+[[package]]
+name = "winapi-util"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf221c93e13a30d793f7645a0e7762c55d169dbb0a49671918a2319d289b10bb"
+dependencies = [
+ "windows-sys 0.59.0",
+]
+
 [[package]]
 name = "winapi-x86_64-pc-windows-gnu"
 version = "0.4.0"
@@ -2346,6 +2365,12 @@ version = "0.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ea2f10b9bb0928dfb1b42b65e1f9e36f7f54dbdf08457afefb38afcdec4fa2bb"

+[[package]]
+name = "yansi"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cfe53a6657fd280eaa890a3bc59152892ffa3e30101319d168b781ed6529b049"
+
 [[package]]
 name = "yoke"
 version = "0.8.0"
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -30,17 +30,29 @@ repository.workspace = true
 dev.panic = "abort"
 release.panic = "abort"

+[[test]]
+name = "main"
+harness = false
+
+[features]
+default = ["task", "time", "fs", "net"]
+task = ["lb/task"]
+time = ["lb/time"]
+fs = ["lb/fs"]
+net = ["lb/net"]
+tokio-console = ["dep:console-subscriber"]
+
 [dependencies]
 clap = { version = "4.5.40", features = ["derive", "env"] }
-console-subscriber = "0.4.1"
-lb = { path = "crates/lb" }
+console-subscriber = { version = "0.4.1", optional = true }
+lb = { path = "crates/lb", features = ["runtime"] }
 luajit = { path = "crates/luajit", features = ["runtime"] }
 mimalloc = "0.1.47"
 owo-colors = "4.2.1"
 sysexits = "0.9.0"
-tokio = { version = "1.45.1", features = ["full", "tracing"] }
+tokio = { version = "1.45.1", features = ["rt", "rt-multi-thread"] }
 tracing = "0.1.41"
-tracing-subscriber = "0.3.19"
+tracing-subscriber = { version = "0.3.19", features = ["env-filter"] }

 [build-dependencies]
 vergen-git2 = { version = "1.0.7", features = ["cargo", "rustc"] }
--- a/bacon.toml
+++ b/bacon.toml
@@ -1,6 +1,10 @@
+default_job = "test"
+
 [jobs.test]
-command = ["cargo", "test", "--workspace"]
+command = ["cargo", "test"]
+watch = ["*.lua"]
 need_stdout = true
+background = false

 [jobs.doc]
 command = ["cargo", "doc", "--workspace"]
--- a/crates/lb/Cargo.toml
+++ b/crates/lb/Cargo.toml
@@ -7,15 +7,21 @@ authors.workspace = true
 homepage.workspace = true
 repository.workspace = true

+[features]
+runtime = ["tokio/rt"]
+task = ["tokio/rt", "tokio/time"]
+time = []
+fs = ["tokio/fs", "dep:walkdir", "dep:globset", "dep:tempfile"]
+net = ["tokio/net", "tokio/io-util"]
+
 [dependencies]
-camino = "1.1.10"
 derive_more = { version = "2.0.1", features = ["full"] }
+globset = { version = "0.4.16", optional = true }
 luaffi = { path = "../luaffi" }
+luaify = { path = "../luaify" }
 luajit = { path = "../luajit" }
 sysexits = "0.9.0"
-tokio = { version = "1.45.1", features = ["rt", "time", "fs", "net", "process", "signal", "tracing"] }
-tracing = "0.1.41"
-
-[dev-dependencies]
-luaify = { path = "../luaify" }
-tokio = { version = "1.45.1", features = ["full"] }
+tempfile = { version = "3.20.0", optional = true }
+thiserror = "2.0.12"
+tokio = { version = "1.45.1" }
+walkdir = { version = "2.5.0", optional = true }
--- a/crates/lb/src/channel.rs
+++ b/crates/lb/src/channel.rs
@@ -1,11 +1,26 @@
-// use flume::{Receiver, Sender};
+//! # Channel library
+//!
+//! The `lb:chan` library provides primitives for asynchronous communication between tasks via
+//! message passing channels.
+//!
+//! ## Exports
+//!
+//! See [`lb_chanlib`] for items exported by this library.
 use luaffi::{cdef, metatype};

-#[cdef]
-pub struct lb_libchannel;
+/// Items exported by the `lb:chan` library.
+///
+/// This library can be acquired by calling
+/// [`require("lb:chan")`](https://www.lua.org/manual/5.1/manual.html#pdf-require).
+///
+/// ```lua
+/// local chan = require("lb:chan");
+/// ```
+#[cdef(module = "lb:chan")]
+pub struct lb_chanlib;

 #[metatype]
-impl lb_libchannel {
+impl lb_chanlib {
    #[new]
    extern "Lua-C" fn new() -> Self {
        Self
@@ -17,7 +32,7 @@ impl lb_libchannel {
        (send, recv)
    }

-    extern "Lua" fn bounded(self, cap: number) {
+    extern "Lua" fn bounded(self, cap: u32) {
        assert(cap >= 0, "channel capacity must be nonnegative");
        let (send, recv) = (__new(__ct.lb_sender), __new(__ct.lb_receiver));
        self.__bounded(cap, send, recv);
--- a/crates/lb/src/fs.rs
+++ b/crates/lb/src/fs.rs
@@ -1,34 +1,645 @@
-//! The `lb:fs` module provides utilities for interacting with the file system asynchronously.
+//! # Filesystem library
 //!
-//! # Exports
+//! The `lb:fs` library provides synchronous and asynchronous utilities for interacting with the
+//! filesystem.
 //!
-//! See [`lb_libfs`] for items exported by this module.
+//! ## Asynchronous by default
+//!
+//! Filesystem operations are blocking by nature; to provide asynchronicity, luby performs blocking
+//! operations in a background thread pool by default. Synchronous complements to all asynchronous
+//! functions are always provided.
+//!
+//! ## Exports
+//!
+//! See [`lb_fslib`] for items exported by this library.
 use luaffi::{cdef, metatype};
-use std::io;
-use tokio::fs;
+use std::{
+    cell::{BorrowError, BorrowMutError, RefCell},
+    path::PathBuf,
+    time::SystemTime,
+};
+use thiserror::Error;

-/// Items exported by the `lb:fs` module.
+/// Errors that can be thrown by this library.
 ///
-/// This module can be obtained by calling `require` in Lua.
+/// Functions which return this error will **throw**. The error message can be caught by using
+/// [`pcall(f, ...)`](https://www.lua.org/manual/5.1/manual.html#pdf-pcall).
+#[derive(Debug, Error)]
+pub enum Error {
+    /// Attempt to access an object while it is being modified.
+    #[error("cannot access object while it is being modified")]
+    Borrow(#[from] BorrowError),
+    /// Attempt to modify an object while it is in use.
+    #[error("cannot modify object while it is in use")]
+    BorrowMut(#[from] BorrowMutError),
+    /// I/O error.
+    #[error("{0}")]
+    Io(#[from] std::io::Error),
+    /// Walk directory error.
+    #[error("{0}")]
+    Walk(#[from] walkdir::Error),
+    /// Glob pattern error.
+    #[error("{0}")]
+    Glob(#[from] globset::Error),
+}
+
+type Result<T> = std::result::Result<T, Error>;
+
+/// Items exported by the `lb:fs` library.
+///
+/// This library can be acquired by calling
+/// [`require("lb:fs")`](https://www.lua.org/manual/5.1/manual.html#pdf-require).
 ///
 /// ```lua
 /// local fs = require("lb:fs");
 /// ```
-#[cdef]
-pub struct lb_libfs;
+#[cdef(module = "lb:fs")]
+pub struct lb_fslib;

 #[metatype]
-impl lb_libfs {
+impl lb_fslib {
    #[new]
    extern "Lua-C" fn new() -> Self {
        Self
    }

-    pub async extern "Lua-C" fn read(&self, path: &str) -> io::Result<Vec<u8>> {
-        fs::read(path).await
+    /// Reads the entire contents of a file.
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the file does not exist or cannot be read.
+    pub async extern "Lua-C" fn read(path: &str) -> Result<Vec<u8>> {
+        Ok(tokio::fs::read(path).await?)
    }

-    pub extern "Lua-C" fn read_sync(&self, path: &str) -> io::Result<Vec<u8>> {
-        std::fs::read(path)
+    /// Reads the entire contents of a file synchronously.
+    ///
+    /// This is a synchronous complement to [`read`](Self::read).
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the file does not exist or cannot be read.
+    pub extern "Lua-C" fn read_sync(path: &str) -> Result<Vec<u8>> {
+        Ok(std::fs::read(path)?)
+    }
+
+    /// Writes the given contents to a file, replacing its contents if it exists.
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the file cannot be written.
+    pub async extern "Lua-C" fn write(path: &str, contents: &[u8]) -> Result<()> {
+        Ok(tokio::fs::write(path, contents).await?)
+    }
+
+    /// Writes the given contents to a file synchronously, replacing its contents if it exists.
+    ///
+    /// This is a synchronous complement to [`write`](Self::write).
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the file cannot be written.
+    pub extern "Lua-C" fn write_sync(path: &str, contents: &[u8]) -> Result<()> {
+        Ok(std::fs::write(path, contents)?)
+    }
+
+    /// Reads the entries in a directory.
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the directory cannot be read.
+    pub async extern "Lua-C" fn read_dir(path: &str) -> Result<lb_read_dir> {
+        Ok(lb_read_dir::new(tokio::fs::read_dir(path).await?))
+    }
+
+    /// Reads the entries in a directory synchronously.
+    ///
+    /// This is a synchronous complement to [`read_dir`](Self::read_dir).
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the directory cannot be read.
+    pub extern "Lua-C" fn read_dir_sync(path: &str) -> Result<lb_read_dir_sync> {
+        Ok(lb_read_dir_sync::new(std::fs::read_dir(path)?))
+    }
+
+    /// Recursively walks a directory, yielding all entries within it.
+    pub extern "Lua-C" fn walk_dir(path: &str) -> lb_walk_dir {
+        lb_walk_dir::new(walkdir::WalkDir::new(path).into_iter())
+    }
+
+    /// Returns an iterator over all files matching a glob pattern in the current directory.
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the pattern is invalid.
+    pub extern "Lua" fn glob(pattern: &str) -> Result<lb_glob_dir> {
+        Self::glob_dir(".", pattern)
+    }
+
+    /// Returns an iterator over all files matching a glob pattern in the given directory.
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the pattern is invalid.
+    pub extern "Lua-C" fn glob_dir(path: &str, pattern: &str) -> Result<lb_glob_dir> {
+        let prefix = PathBuf::from(path);
+        let iter = walkdir::WalkDir::new(path).min_depth(1).into_iter();
+        let matcher = globset::GlobSet::builder()
+            .add(globset::Glob::new(pattern)?)
+            .build()?;
+
+        Ok(lb_glob_dir::new(iter, matcher, prefix))
+    }
+
+    /// Creates a new temporary directory.
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the temporary directory cannot be created.
+    pub extern "Lua-C" fn temp_dir() -> Result<lb_temp_dir> {
+        Ok(lb_temp_dir::new(tempfile::tempdir()?))
+    }
+
+    /// Creates a new temporary directory inside the specified path.
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the temporary directory cannot be created.
+    pub extern "Lua-C" fn temp_dir_in(path: &str) -> Result<lb_temp_dir> {
+        Ok(lb_temp_dir::new(tempfile::tempdir_in(path)?))
+    }
+}
+
+/// Iterator over the entries in a directory.
+#[derive(Debug)]
+#[cdef]
+pub struct lb_read_dir(#[opaque] RefCell<tokio::fs::ReadDir>);
+
+#[metatype]
+impl lb_read_dir {
+    fn new(iter: tokio::fs::ReadDir) -> Self {
+        Self(RefCell::new(iter))
+    }
+
+    /// Returns the next entry in the directory, or `nil` if there are no more entries.
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the directory cannot be read.
+    #[call]
+    pub async extern "Lua-C" fn next(&self) -> Result<Option<lb_dir_entry>> {
+        Ok(self
+            .0
+            .try_borrow_mut()?
+            .next_entry()
+            .await?
+            .map(lb_dir_entry::new))
+    }
+}
+
+/// Synchronous version of [`lb_read_dir`].
+#[derive(Debug)]
+#[cdef]
+pub struct lb_read_dir_sync(#[opaque] RefCell<std::fs::ReadDir>);
+
+#[metatype]
+impl lb_read_dir_sync {
+    fn new(iter: std::fs::ReadDir) -> Self {
+        Self(RefCell::new(iter))
+    }
+
+    /// Returns the next entry in the directory, or `nil` if there are no more entries.
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the directory cannot be read.
+    #[call]
+    pub extern "Lua-C" fn next(&self) -> Result<Option<lb_dir_entry_sync>> {
+        Ok(self
+            .0
+            .try_borrow_mut()?
+            .next()
+            .transpose()?
+            .map(lb_dir_entry_sync::new))
+    }
+}
+
+/// Entry inside of a directory on the filesystem.
+#[derive(Debug)]
+#[cdef]
+pub struct lb_dir_entry(#[opaque] tokio::fs::DirEntry);
+
+#[metatype]
+impl lb_dir_entry {
+    fn new(entry: tokio::fs::DirEntry) -> Self {
+        Self(entry)
+    }
+
+    /// Returns the full path of this entry.
+    pub extern "Lua-C" fn path(&self) -> String {
+        self.0.path().to_string_lossy().into()
+    }
+
+    /// Returns the file name of this entry.
+    pub extern "Lua-C" fn name(&self) -> String {
+        self.0.file_name().to_string_lossy().into()
+    }
+
+    /// Returns the type of this entry.
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the file type cannot be determined.
+    pub async extern "Lua-C" fn r#type(&self) -> Result<lb_file_type> {
+        Ok(lb_file_type::new(self.0.file_type().await?))
+    }
+
+    /// Returns the metadata for this entry.
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the metadata cannot be retrieved.
+    pub async extern "Lua-C" fn metadata(&self) -> Result<lb_file_meta> {
+        Ok(lb_file_meta::new(self.0.metadata().await?))
+    }
+
+    /// Returns the inode number for this entry.
+    #[cfg(unix)]
+    pub extern "Lua-C" fn ino(&self) -> u64 {
+        self.0.ino()
+    }
+
+    /// Returns the full path of this entry.
+    #[tostring]
+    pub extern "Lua" fn tostring(&self) -> String {
+        self.path()
+    }
+}
+
+/// Synchronous version of [`lb_dir_entry`].
+#[derive(Debug)]
+#[cdef]
+pub struct lb_dir_entry_sync(#[opaque] std::fs::DirEntry);
+
+#[metatype]
+impl lb_dir_entry_sync {
+    fn new(entry: std::fs::DirEntry) -> Self {
+        Self(entry)
+    }
+
+    /// Returns the full path of this entry.
+    pub extern "Lua-C" fn path(&self) -> String {
+        self.0.path().to_string_lossy().into()
+    }
+
+    /// Returns the file name of this entry.
+    pub extern "Lua-C" fn name(&self) -> String {
+        self.0.file_name().to_string_lossy().into()
+    }
+
+    /// Returns the type of this entry.
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the file type cannot be determined.
+    pub extern "Lua-C" fn r#type(&self) -> Result<lb_file_type> {
+        Ok(lb_file_type::new(self.0.file_type()?))
+    }
+
+    /// Returns the metadata for this entry.
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the metadata cannot be retrieved.
+    pub extern "Lua-C" fn metadata(&self) -> Result<lb_file_meta> {
+        Ok(lb_file_meta::new(self.0.metadata()?))
+    }
+
+    /// Returns the inode number for this entry.
+    #[cfg(unix)]
+    pub extern "Lua-C" fn ino(&self) -> u64 {
+        use std::os::unix::fs::DirEntryExt;
+        self.0.ino()
+    }
+
+    /// Returns the full path of this entry.
+    #[tostring]
+    pub extern "Lua" fn tostring(&self) -> String {
+        self.path()
+    }
+}
+
+/// Structure representing the type of a file with accessors for each file type.
+#[derive(Debug)]
+#[cdef]
+pub struct lb_file_type(#[opaque] std::fs::FileType);
+
+#[metatype]
+impl lb_file_type {
+    fn new(ty: std::fs::FileType) -> Self {
+        Self(ty)
+    }
+
+    /// Returns `true` if this file type is a directory.
+    pub extern "Lua-C" fn is_dir(&self) -> bool {
+        self.0.is_dir()
+    }
+
+    /// Returns `true` if this file type is a regular file.
+    pub extern "Lua-C" fn is_file(&self) -> bool {
+        self.0.is_file()
+    }
+
+    /// Returns `true` if this file type is a symbolic link.
+    pub extern "Lua-C" fn is_symlink(&self) -> bool {
+        self.0.is_file()
+    }
+
+    /// Returns the string `"file"` if this is a regular file, `"dir"` if this is a directory,
+    /// `"symlink"` if this is a symbolic link, or `"other"` if it is some other type of file.
+    #[tostring]
+    pub extern "Lua-C" fn tostring(&self) -> String {
+        if self.0.is_file() {
+            "file"
+        } else if self.0.is_dir() {
+            "dir"
+        } else if self.0.is_symlink() {
+            "symlink"
+        } else {
+            "other"
+        }
+        .into()
+    }
+}
+
+/// Metadata information about a file.
+#[derive(Debug)]
+#[cdef]
+pub struct lb_file_meta(#[opaque] std::fs::Metadata);
+
+#[metatype]
+impl lb_file_meta {
+    fn new(meta: std::fs::Metadata) -> Self {
+        Self(meta)
+    }
+
+    /// Returns `true` if this file is a directory.
+    pub extern "Lua-C" fn is_dir(&self) -> bool {
+        self.0.is_dir()
+    }
+
+    /// Returns `true` if this file is a regular file.
+    pub extern "Lua-C" fn is_file(&self) -> bool {
+        self.0.is_file()
+    }
+
+    /// Returns `true` if this file is a symbolic link.
+    pub extern "Lua-C" fn is_symlink(&self) -> bool {
+        self.0.is_file()
+    }
+
+    /// Returns the type of this file.
+    pub extern "Lua-C" fn r#type(&self) -> lb_file_type {
+        lb_file_type::new(self.0.file_type())
+    }
+
+    /// Returns the size of this file in bytes.
+    pub extern "Lua-C" fn size(&self) -> u64 {
+        self.0.len()
+    }
+
+    /// Returns the permissions of this file.
+    pub extern "Lua-C" fn perms(&self) -> lb_file_perms {
+        lb_file_perms::new(self.0.permissions())
+    }
+
+    /// Returns the creation time of this file as seconds since the Unix epoch.
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the creation time cannot be retrieved.
+    pub extern "Lua-C" fn created(&self) -> Result<f64> {
+        Ok(self
+            .0
+            .created()?
+            .duration_since(SystemTime::UNIX_EPOCH)
+            .map(|dur| dur.as_secs_f64())
+            .unwrap_or(0.))
+    }
+
+    /// Returns the modification time of this file as seconds since the Unix epoch.
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the modification time cannot be retrieved.
+    pub extern "Lua-C" fn modified(&self) -> Result<f64> {
+        Ok(self
+            .0
+            .modified()?
+            .duration_since(SystemTime::UNIX_EPOCH)
+            .map(|dur| dur.as_secs_f64())
+            .unwrap_or(0.))
+    }
+
+    /// Returns the last access time of this file as seconds since the Unix epoch.
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the access time cannot be retrieved.
+    pub extern "Lua-C" fn accessed(&self) -> Result<f64> {
+        Ok(self
+            .0
+            .accessed()?
+            .duration_since(SystemTime::UNIX_EPOCH)
+            .map(|dur| dur.as_secs_f64())
+            .unwrap_or(0.))
+    }
+
+    /// Returns a string representation of this file's metadata.
+    #[tostring]
+    pub extern "Lua-C" fn tostring(&self) -> String {
+        let ty = self.0.file_type();
+        if ty.is_file() {
+            format!("file {}", self.0.len())
+        } else if ty.is_dir() {
+            "dir".into()
+        } else if ty.is_symlink() {
+            "symlink".into()
+        } else {
+            "other".into()
+        }
+    }
+}
+
+/// Representation of the various permissions on a file.
+#[derive(Debug)]
+#[cdef]
+pub struct lb_file_perms(#[opaque] RefCell<std::fs::Permissions>);
+
+#[metatype]
+impl lb_file_perms {
+    fn new(perms: std::fs::Permissions) -> Self {
+        Self(RefCell::new(perms))
+    }
+
+    /// Returns `true` if the readonly flag is set.
+    pub extern "Lua-C" fn readonly(&self) -> bool {
+        self.0.borrow().readonly()
+    }
+
+    /// Sets the readonly flag.
+    pub extern "Lua-C" fn set_readonly(&self, readonly: bool) {
+        self.0.borrow_mut().set_readonly(readonly);
+    }
+}
+
+/// Iterator for recursively descending into a directory.
+#[derive(Debug)]
+#[cdef]
+pub struct lb_walk_dir(#[opaque] RefCell<walkdir::IntoIter>);
+
+#[metatype]
+impl lb_walk_dir {
+    fn new(iter: walkdir::IntoIter) -> Self {
+        Self(RefCell::new(iter))
+    }
+
+    /// Returns the next entry in the walk, or `nil` if there are no more entries.
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the directory cannot be read.
+    #[call]
+    pub extern "Lua-C" fn next(&self) -> Result<Option<lb_walk_dir_entry>> {
+        Ok(self
+            .0
+            .try_borrow_mut()?
+            .next()
+            .transpose()?
+            .map(lb_walk_dir_entry::new))
+    }
+}
+
+/// Entry inside of a directory on the filesystem obtained from [`lb_walk_dir`].
+#[derive(Debug)]
+#[cdef]
+pub struct lb_walk_dir_entry(#[opaque] walkdir::DirEntry);
+
+#[metatype]
+impl lb_walk_dir_entry {
+    fn new(entry: walkdir::DirEntry) -> Self {
+        Self(entry)
+    }
+
+    /// Returns the full path of this entry.
+    pub extern "Lua-C" fn path(&self) -> String {
+        self.0.path().to_string_lossy().into()
+    }
+
+    /// Returns the file name of this entry.
+    pub extern "Lua-C" fn name(&self) -> String {
+        self.0.file_name().to_string_lossy().into()
+    }
+
+    /// Returns the type of this entry.
+    pub extern "Lua-C" fn r#type(&self) -> lb_file_type {
+        lb_file_type::new(self.0.file_type())
+    }
+
+    /// Returns the metadata for this entry.
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the metadata cannot be retrieved.
+    pub extern "Lua-C" fn metadata(&self) -> Result<lb_file_meta> {
+        Ok(lb_file_meta::new(self.0.metadata()?))
+    }
+
+    /// Returns `true` if this entry was created from a symbolic link.
+    pub extern "Lua-C" fn is_symlink(&self) -> bool {
+        self.0.path_is_symlink()
+    }
+
+    /// Returns the depth of this entry in the walk.
+    pub extern "Lua-C" fn depth(&self) -> u32 {
+        self.0.depth() as u32
+    }
+
+    /// Returns the inode number for this entry.
+    #[cfg(unix)]
+    pub extern "Lua-C" fn ino(&self) -> u64 {
+        use walkdir::DirEntryExt;
+        self.0.ino()
+    }
+
+    /// Returns the full path of this entry.
+    #[tostring]
+    pub extern "Lua" fn tostring(&self) -> String {
+        self.path()
+    }
+}
+
+/// Iterator that yields paths from the filesystem that match a particular pattern.
+#[derive(Debug)]
+#[cdef]
+pub struct lb_glob_dir {
+    #[opaque]
+    iter: RefCell<walkdir::IntoIter>,
+    #[opaque]
+    matcher: globset::GlobSet,
+    #[opaque]
+    prefix: PathBuf,
+}
+
+#[metatype]
+impl lb_glob_dir {
+    fn new(iter: walkdir::IntoIter, matcher: globset::GlobSet, prefix: PathBuf) -> Self {
+        Self {
+            iter: RefCell::new(iter),
+            matcher,
+            prefix,
+        }
+    }
+
+    /// Returns the next entry matching the glob pattern, or `nil` if there are no more entries.
+    ///
+    /// # Errors
+    ///
+    /// This function may throw if the directory cannot be read.
+    #[call]
+    pub extern "Lua-C" fn next(&self) -> Result<Option<lb_walk_dir_entry>> {
+        while let Some(res) = self.iter.try_borrow_mut()?.next() {
+            let entry = res?;
+            let path = entry.path().strip_prefix(&self.prefix).unwrap();
+            if self.matcher.is_match(path) {
+                return Ok(Some(lb_walk_dir_entry::new(entry)));
+            }
+        }
+
+        Ok(None)
+    }
+}
+
+/// Directory in the filesystem that is automatically deleted when it is garbage-collected.
+#[derive(Debug)]
+#[cdef]
+pub struct lb_temp_dir(#[opaque] tempfile::TempDir);
+
+#[metatype]
+impl lb_temp_dir {
+    fn new(dir: tempfile::TempDir) -> Self {
+        Self(dir)
+    }
+
+    /// Returns the full path of this temporary directory.
+    pub extern "Lua-C" fn path(&self) -> String {
+        self.0.path().to_string_lossy().into()
+    }
+
+    /// Returns the full path of this temporary directory.
+    #[tostring]
+    pub extern "Lua" fn tostring(&self) -> String {
+        self.path()
    }
 }
--- a/crates/lb/src/lib.rs
+++ b/crates/lb/src/lib.rs
@@ -1,5 +1,13 @@
-pub mod channel;
+//! luby standard library
+#[cfg(feature = "task")]
+pub mod chan;
+#[cfg(feature = "fs")]
 pub mod fs;
+#[cfg(feature = "net")]
 pub mod net;
+#[cfg(feature = "runtime")]
 pub mod runtime;
+#[cfg(feature = "task")]
 pub mod task;
+#[cfg(feature = "time")]
+pub mod time;
--- a/crates/lb/src/net.rs
+++ b/crates/lb/src/net.rs
--- a/crates/lb/src/runtime.lua
+++ b/crates/lb/src/runtime.lua
@@ -1,5 +0,0 @@
-local task = require("lb:task")
-
-function spawn(f, ...)
-  return task:spawn(f, ...)
-end
--- a/crates/lb/src/runtime.rs
+++ b/crates/lb/src/runtime.rs
@@ -1,85 +1,141 @@
-use crate::{channel::lb_libchannel, fs::lb_libfs, net::lb_libnet, task::lb_libtask};
+#![doc(hidden)]
 use derive_more::{Deref, DerefMut};
-use luaffi::{Registry, Type};
-use luajit::{Chunk, State};
-use std::fmt::Display;
+use luaffi::{Module, Registry};
+use luaify::luaify_chunk;
+use luajit::{Chunk, Index, NewTable, State};
+use std::rc::Rc;
 use tokio::{
    task::{JoinHandle, LocalSet, futures::TaskLocalFuture, spawn_local},
    task_local,
 };

-#[derive(Debug, Default)]
+pub type ErrorFn = dyn Fn(&luajit::Error);
+
 pub struct Builder {
    registry: Registry,
+    report_err: Rc<ErrorFn>,
+    prohibit_globals: bool,
 }

 impl Builder {
    pub fn new() -> Self {
-        let mut registry = Registry::new();
-
-        registry
-            .preload::<lb_libtask>("lb:task")
-            .preload::<lb_libchannel>("lb:channel")
-            .preload::<lb_libfs>("lb:fs")
-            .preload::<lb_libnet>("lb:net");
-
-        Self { registry }
+        Self {
+            registry: Registry::new(),
+            report_err: Rc::new(|err| match err.trace() {
+                Some(trace) => eprintln!("unhandled lua error: {err}\n{trace}"),
+                None => eprintln!("unhandled lua error: {err}"),
+            }),
+            prohibit_globals: false,
        }
-
-    pub fn module<T: Type>(&mut self, name: impl Display) -> &mut Self {
-        self.registry.preload::<T>(name);
-        self
    }

    pub fn registry(&self) -> &Registry {
        &self.registry
    }

+    pub fn unhandled_error(&mut self, handler: impl Fn(&luajit::Error) + 'static) -> &mut Self {
+        self.report_err = Rc::new(handler);
+        self
+    }
+
+    pub fn prohibit_globals(&mut self, enabled: bool) -> &mut Self {
+        self.prohibit_globals = enabled;
+        self
+    }
+
+    pub fn module<T: Module>(&mut self) -> &mut Self {
+        self.registry.preload::<T>();
+        self
+    }
+
    pub fn build(&self) -> luajit::Result<Runtime> {
+        let mut state = State::new()?;
+        let chunk = Chunk::new(self.registry.build()).with_path("[luby]");
+        state.eval(&chunk, 0, Some(0))?;
+
+        if self.prohibit_globals {
+            let mut s = state.guard();
+            s.eval(
+                &Chunk::new(luaify_chunk!({
+                    return |self, key, value| {
+                        error(("undeclared local variable '%s'").format(key), 2);
+                    };
+                })),
+                0,
+                Some(1),
+            )
+            .unwrap();
+            s.push(NewTable::new());
+            (s.push("__index"), s.push_idx(-3), s.set(-3));
+            (s.push("__newindex"), s.push_idx(-3), s.set(-3));
+            s.set_metatable(Index::globals());
+        }
+
        Ok(Runtime {
-            state: {
-                let mut s = State::new()?;
-                let mut chunk = Chunk::new(self.registry.done());
-                chunk.extend(include_bytes!("./runtime.lua"));
-                s.eval(chunk.path("[luby]"), 0, 0)?;
-                s
+            cx: Context {
+                state,
+                report_err: self.report_err.clone(),
            },
            tasks: LocalSet::new(),
        })
    }
 }

-#[derive(Debug, Deref, DerefMut)]
+#[derive(Deref, DerefMut)]
 pub struct Runtime {
    #[deref]
    #[deref_mut]
-    state: State,
+    cx: Context,
    tasks: LocalSet,
 }

-task_local! {
-    static STATE: State;
-}
-
 impl Runtime {
    pub fn spawn<T: 'static>(
        &self,
-        f: impl AsyncFnOnce(&mut State) -> T + 'static,
+        f: impl AsyncFnOnce(&mut Context) -> T + 'static,
    ) -> JoinHandle<T> {
        self.tasks
-            .spawn_local(async move { f(&mut STATE.with(|s| s.new_thread())).await })
+            .spawn_local(async move { f(&mut CURRENT.with(|s| s.new_thread())).await })
    }
 }

-pub fn spawn<T: 'static>(f: impl AsyncFnOnce(&mut State) -> T + 'static) -> JoinHandle<T> {
-    spawn_local(async move { f(&mut STATE.with(|s| s.new_thread())).await })
-}
-
 impl IntoFuture for Runtime {
    type Output = ();
-    type IntoFuture = TaskLocalFuture<State, LocalSet>;
+    type IntoFuture = TaskLocalFuture<Context, LocalSet>;

    fn into_future(self) -> Self::IntoFuture {
-        STATE.scope(self.state, self.tasks)
+        CURRENT.scope(self.cx, self.tasks)
    }
 }
+
+task_local! {
+    static CURRENT: Context;
+}
+
+#[derive(Deref, DerefMut)]
+pub struct Context {
+    #[deref]
+    #[deref_mut]
+    state: State,
+    report_err: Rc<ErrorFn>,
+}
+
+impl Context {
+    pub fn new_thread(&self) -> Self {
+        Self {
+            state: State::new_thread(&self.state),
+            report_err: self.report_err.clone(),
+        }
+    }
+
+    pub fn report_error(&self, err: &luajit::Error) {
+        (self.report_err)(&err);
+    }
+}
+
+pub fn spawn<T: 'static>(f: impl AsyncFnOnce(&mut Context) -> T + 'static) -> JoinHandle<T> {
+    // SAFETY: `new_thread` must be called inside `spawn_local` because this free-standing spawn
+    // function may be called via ffi from lua, and it is not safe to access the lua state within
+    // ffi calls.
+    spawn_local(async move { f(&mut CURRENT.with(|s| s.new_thread())).await })
+}
--- a/crates/lb/src/task.lua
+++ b/crates/lb/src/task.lua
@@ -0,0 +1,3 @@
+local task = require("lb:task")
+sleep = task.sleep
+spawn = task.spawn
--- a/crates/lb/src/task.rs
+++ b/crates/lb/src/task.rs
@@ -1,46 +1,117 @@
+//! # Task library
+//!
+//! The `lb:task` library primitives for asynchronous communication between tasks via message
+//! passing channels.
+//!
+//! ## Exports
+//!
+//! See [`lb_tasklib`] for items exported by this library.
 use crate::runtime::spawn;
-use luaffi::{cdef, metatype};
-use std::{ffi::c_int, process};
-use tokio::task::JoinHandle;
+use luaffi::{
+    cdef,
+    marker::{function, many},
+    metatype,
+};
+use std::{cell::RefCell, ffi::c_int, time::Duration};
+use tokio::{task::JoinHandle, time::sleep};

-#[cdef]
-pub struct lb_libtask;
+/// Items exported by the `lb:task` library.
+///
+/// This library can be acquired by calling
+/// [`require("lb:task")`](https://www.lua.org/manual/5.1/manual.html#pdf-require).
+///
+/// ```lua
+/// local task = require("lb:task");
+/// ```
+#[cdef(module = "lb:task")]
+pub struct lb_tasklib;

 #[metatype]
-impl lb_libtask {
+#[include("task.lua")]
+impl lb_tasklib {
    #[new]
    extern "Lua-C" fn new() -> Self {
        Self
    }

-    pub extern "Lua" fn spawn(self, f: function, ...) {
-        // pack the function and its arguments into a table and pass its ref to rust
-        self.__spawn(__ref(__tpack(f, variadic!())))
+    pub async extern "Lua-C" fn sleep(ms: f64) {
+        sleep(Duration::from_secs_f64(ms.max(0.) / 1000.)).await;
    }

-    extern "Lua-C" fn __spawn(&self, key: c_int) -> lb_task {
-        let handle = spawn(async move |s| {
-            // SAFETY: key is always unique, created by __ref above
-            let arg = unsafe { s.new_ref_unchecked(key) };
-            s.resize(0);
-            s.push(arg);
-            let narg = s.unpack(1, 1, None) - 1;
-            println!("{s:?}");
-            if let Err(_err) = s.call_async(narg, 0).await {
-                process::exit(1)
+    pub extern "Lua" fn spawn(f: function, ...) -> lb_task {
+        // pack the function and its arguments into a table and pass its ref to rust.
+        //
+        // this "state" table is used from rust-side to call the function with its args, and it's
+        // also reused to store its return values that the task handle can return when awaited. the
+        // ref is owned by the task handle and unref'ed when it's gc'ed.
+        assert(
+            r#type(f) == "function",
+            concat!("function expected in argument 'f', got ", r#type(f)),
+        );
+        // we need two refs: one for the spawn call, and the other for the task handle. this is to
+        // ensure the task handle isn't gc'ed and the state table unref'ed before the spawn callback
+        // runs and puts the state table on the stack.
+        let state = __tpack(f, variadic!());
+        Self::__spawn(__ref(state), __ref(state))
+    }
+
+    extern "Lua-C" fn __spawn(spawn_ref: c_int, handle_ref: c_int) -> lb_task {
+        let handle = spawn(async move |cx| {
+            // SAFETY: handle_ref is always unique, created in Self::spawn above.
+            let state = unsafe { luajit::Ref::from_raw(cx, spawn_ref) };
+            let mut s = cx.guard();
+            s.resize(0);
+            s.push(state); // this drops the state table ref, but the table is still on the stack
+            let narg = s.unpack(1, 1, None) - 1; // unpack the function and its args from the state table
+            match s.call_async(narg, None).await {
+                Ok(nret) => {
+                    s.pack(1, nret); // pack the return values back into the state table
+                }
+                Err(err) => {
+                    drop(s);
+                    cx.report_error(&err);
+                }
            }
-            println!("{s:?}");
        });

-        lb_task { handle }
+        // spawn_ref is owned by the task handle and unref'ed there when the handle gets gc'ed
+        lb_task::new(handle, handle_ref)
    }
 }

+/// Handle for an asynchronous task created by [`spawn`](lb_tasklib::spawn).
 #[cdef]
 pub struct lb_task {
    #[opaque]
-    handle: JoinHandle<()>,
+    handle: RefCell<Option<JoinHandle<()>>>,
+    __ref: c_int,
 }

 #[metatype]
-impl lb_task {}
+impl lb_task {
+    fn new(handle: JoinHandle<()>, ref_key: c_int) -> Self {
+        lb_task {
+            handle: RefCell::new(Some(handle)),
+            __ref: ref_key,
+        }
+    }
+
+    pub async extern "Lua" fn r#await(&self) -> many {
+        self.__await();
+        let ret = __registry[self.__ref];
+        __tunpack(ret, 1, ret.n)
+    }
+
+    async extern "Lua-C" fn __await(&self) {
+        if let Some(handle) = self.handle.borrow_mut().take() {
+            handle
+                .await // task handler should never panic
+                .unwrap_or_else(|err| std::panic::resume_unwind(err.into_panic()));
+        }
+    }
+
+    #[gc]
+    extern "Lua" fn gc(&self) {
+        __unref(self.__ref);
+    }
+}
--- a/crates/lb/src/time.rs
+++ b/crates/lb/src/time.rs
@@ -0,0 +1,30 @@
+use luaffi::{cdef, metatype};
+
+#[cdef(module = "lb:time")]
+pub struct lb_timelib;
+
+#[metatype]
+impl lb_timelib {
+    #[new]
+    extern "Lua-C" fn new() -> Self {
+        Self
+    }
+
+    pub extern "Lua-C" fn instant() -> lb_instant {
+        lb_instant::new(std::time::Instant::now())
+    }
+}
+
+#[cdef]
+pub struct lb_instant(#[opaque] std::time::Instant);
+
+#[metatype]
+impl lb_instant {
+    fn new(instant: std::time::Instant) -> Self {
+        Self(instant)
+    }
+
+    pub extern "Lua-C" fn elapsed(&self) -> f64 {
+        self.0.elapsed().as_secs_f64()
+    }
+}
--- a/crates/lb/tests/fs.lua
+++ b/crates/lb/tests/fs.lua
@@ -0,0 +1,17 @@
+local ok, fs = pcall(require, "lb:fs")
+if not ok then return end
+
+describe("temp files", function()
+  test("temp_dir cleans itself", function()
+    local path
+    do
+      local dir = fs.temp_dir()
+      path = dir:path()
+      assert(path and path ~= "")
+      fs.write(path .. "/test.txt", "test file")
+      assert(fs.read(path .. "/test.txt") == "test file")
+    end
+    collectgarbage()
+    assert(not pcall(fs.read, path .. "/test.txt"))
+  end)
+end)
--- a/crates/lb/tests/net.lua
+++ b/crates/lb/tests/net.lua
@@ -0,0 +1,188 @@
+local ok, net = pcall(require, "lb:net")
+if not ok then return end
+
+describe("ipaddr", function()
+  test("invalid ipaddr throws", function()
+    assert(not pcall(net.ipaddr, "invalid ip"))
+  end)
+
+  test("comparison", function()
+    local a = net.ipaddr("10.0.0.1")
+    local b = net.ipaddr("10.0.0.1")
+    local c = net.ipaddr("10.0.0.2")
+    assert(a ~= nil and a ~= {} and a ~= "10.0.0.1" and a ~= 167772161)
+    assert(a == a and a == b and a ~= c and b ~= c and c == c and c ~= a)
+    assert(a <= b and a < c and a <= c and b < c and b <= c and a <= a and c <= c)
+    assert(not (a < b or a > b or a > c or b > c or a >= c or b >= c))
+  end)
+
+  test("tostring", function()
+    local ip = net.ipaddr("10.0.0.1")
+    assert(tostring(ip) == "10.0.0.1")
+  end)
+end)
+
+describe("tcp", function()
+  describe("socket", function()
+    test("bind", function()
+      local socket = net.bind_tcp("127.0.0.1")
+      -- binds to the correct port
+      assert(tostring(socket:local_addr():ip()) == "127.0.0.1")
+      assert(socket:local_addr():port() ~= 0)
+      -- should not be able to rebind socket
+      assert(not pcall(socket.bind, socket, net.socketaddr("127.0.0.1")))
+    end)
+
+    test("options", function()
+      local socket = net.tcp()
+      -- keepalive
+      socket:set_keepalive(true)
+      assert(socket:keepalive() == true)
+      socket:set_keepalive(false)
+      assert(socket:keepalive() == false)
+      -- reuseaddr
+      socket:set_reuseaddr(true)
+      assert(socket:reuseaddr() == true)
+      socket:set_reuseaddr(false)
+      assert(socket:reuseaddr() == false)
+      -- reuseport not always supported on all platforms
+      -- sendbuf
+      socket:set_sendbuf(4096)
+      assert(socket:sendbuf() >= 4096)
+      assert(not pcall(socket.set_sendbuf, socket, 0))
+      assert(not pcall(socket.set_sendbuf, socket, -1))
+      -- recvbuf
+      socket:set_recvbuf(4096)
+      assert(socket:recvbuf() >= 4096)
+      assert(not pcall(socket.set_recvbuf, socket, 0))
+      assert(not pcall(socket.set_recvbuf, socket, -1))
+      -- linger
+      socket:set_linger(0)
+      assert(socket:linger() == 0)
+      socket:set_linger(2)
+      assert(math.abs(socket:linger() - 2) < 0.1)
+      socket:set_linger(-1)
+      assert(socket:linger() == 0)
+      -- nodelay
+      socket:set_nodelay(true)
+      assert(socket:nodelay() == true)
+      socket:set_nodelay(false)
+      assert(socket:nodelay() == false)
+    end)
+
+    test("can't use socket after conversion", function()
+      local socket = net.tcp()
+      socket:bind(net.socketaddr("127.0.0.1"))
+      socket:listen(10) -- convert to listener
+      assert(not pcall(socket.listen, socket, 10)) -- socket consumed
+      assert(not pcall(socket.local_addr, socket))
+    end)
+  end)
+
+  describe("stream", function()
+    test("no concurrent two reads/writes", function()
+      local listener = net.listen_tcp(net.localhost())
+      local client = net.connect_tcp(listener:local_addr())
+      local server = listener()
+      local reader = spawn(function()
+        assert(client:read(1) == nil) -- this should block first, then return nil from disconnection
+      end)
+      spawn(function()
+        assert(not pcall(client.read, client, 1)) -- this should fail, since the first task is still reading
+      end):await()
+      server:shutdown()
+      reader:await()
+    end)
+
+    test("allow concurrent read/write", function()
+      local listener = net.listen_tcp(net.localhost())
+      local client = net.connect_tcp(listener:local_addr())
+      local server = listener()
+      local reader = spawn(function()
+        assert(client:read(1) == nil) -- this should block first, then return nil from disconnection
+      end)
+      spawn(function()
+        client:write("hello") -- should be able to write while the first task is reading
+      end):await()
+      server:shutdown()
+      reader:await()
+    end)
+
+    test("stop reading from disconnected stream", function()
+      local listener = net.listen_tcp(net.localhost())
+      local client = net.connect_tcp(listener:local_addr())
+      local server = listener()
+      local reader = spawn(function()
+        while client:read(4) ~= nil do
+        end
+        assert(client:try_read(4) == nil)
+        assert(client:read_partial(4) == nil)
+        assert(client:read(4) == nil)
+      end)
+      for _ = 1, 10 do
+        assert(server:write("ping") == true)
+      end
+      sleep(100)
+      server:shutdown()
+      server = nil
+      collectgarbage()
+      reader:await()
+    end)
+
+    test("stop writing to disconnected stream", function()
+      local listener = net.listen_tcp(net.localhost())
+      local client = net.connect_tcp(listener:local_addr())
+      local server = listener()
+      local writer = spawn(function()
+        while client:write("pong") do
+        end
+        assert(client:try_write("pong") == nil)
+        assert(client:write_partial("pong") == nil)
+        assert(client:write("pong") == false)
+      end)
+      for _ = 1, 10 do
+        assert(server:read(4) == "pong")
+      end
+      sleep(100)
+      server:shutdown()
+      server = nil
+      collectgarbage()
+      writer:await()
+    end)
+  end)
+
+  describe("listener", function()
+    test("accept", function()
+      local listener = net.listen_tcp(net.localhost())
+      local addr = listener:local_addr()
+      local accepted = false
+      local client = net.tcp()
+      local accepted_stream
+      listener:on_accept(function(stream)
+        accepted = true
+        accepted_stream = stream
+        -- configure stream
+        stream:set_nodelay(true)
+        assert(stream:nodelay() == true)
+      end)
+      -- connect client
+      local client_stream = client:connect(addr)
+      local server_stream = listener()
+      assert(accepted)
+      assert(accepted_stream ~= nil)
+      -- check addresses
+      assert(server_stream:local_addr() ~= nil)
+      assert(server_stream:peer_addr() ~= nil)
+      assert(client_stream:local_addr() ~= nil)
+      assert(client_stream:peer_addr() ~= nil)
+      -- test data transfer
+      server_stream:write("hello")
+      local buf = client_stream:read(5)
+      assert(buf ~= nil and #buf == 5)
+      assert(buf == "hello")
+      -- shutdown
+      server_stream:shutdown()
+      client_stream:shutdown()
+    end)
+  end)
+end)
--- a/crates/lb/tests/net.rs
+++ b/crates/lb/tests/net.rs
@@ -1,32 +0,0 @@
-use lb::runtime;
-use luaify::luaify;
-use luajit::{Chunk, LoadMode};
-use tokio::test;
-
-async fn run_lua(s: &'static str) {
-    let rt = runtime::Builder::new().build().unwrap();
-    let task = rt.spawn(async move |state| {
-        println!("executing test chunk: {s}");
-
-        state
-            .load(Chunk::new(s).mode(LoadMode::TEXT))
-            .unwrap_or_else(|err| panic!("{err}"));
-
-        state
-            .call_async(0, 0)
-            .await
-            .unwrap_or_else(|err| panic!("{err}"));
-    });
-
-    rt.await;
-    task.await.unwrap_or_else(|err| panic!("{err}"));
-}
-
-#[test]
-async fn ipaddr() {
-    run_lua(luaify!({
-        let net = require("lb:net");
-        print(net.ipaddr("127.0.0.1"));
-    }))
-    .await
-}
--- a/crates/lb/tests/task.lua
+++ b/crates/lb/tests/task.lua
@@ -0,0 +1,189 @@
+local ok, task = pcall(require, "lb:task")
+if not ok then return end
+
+describe("spawn", function()
+  test("callback receives args", function()
+    spawn(function(...)
+      assert(select("#", ...) == 0)
+    end):await()
+
+    spawn(function(...)
+      assert(select("#", ...) == 1)
+      assert((...) == nil)
+    end, nil):await()
+
+    spawn(function(...)
+      assert(select("#", ...) == 4)
+      local args = table.pack(...)
+      assert(args[1] == 1 and args[2] == 2 and args[3] == nil and args[4] == 3)
+    end, 1, 2, nil, 3):await()
+  end)
+
+  test("await returns callback results", function()
+    local res = table.pack(spawn(function()
+      -- no returns
+    end):await())
+    assert(res.n == 0)
+
+    local res = table.pack(spawn(function()
+      return nil
+    end):await())
+    assert(res.n == 1 and res[1] == nil)
+
+    local res = table.pack(spawn(function()
+      return 1, 2, nil, 3
+    end):await())
+    assert(res.n == 4 and res[1] == 1 and res[2] == 2 and res[3] == nil and res[4] == 3)
+  end)
+
+  test("handles invalid args", function()
+    assert(not pcall(spawn))
+    assert(not pcall(spawn, 123))
+    assert(not pcall(spawn, 1, 2, 3))
+    assert(not pcall(spawn, {}, 2, 3))
+  end)
+
+  test("callback args and results", function()
+    local res = table.pack(spawn(function(...)
+      assert(select("#", ...) == 5)
+      local args = table.pack(...)
+      assert(args[1] == 5 and args[2] == 4 and args[3] == nil and args[4] == 3, args[5] == nil)
+      return 1, 3, nil
+    end, 5, 4, nil, 3, nil):await())
+    assert(res.n == 3 and res[1] == 1 and res[2] == 3 and res[3] == nil)
+  end)
+
+  test("large number of args", function()
+    local args = {}
+    for i = 1, 1000 do
+      args[i] = i
+    end
+    local res = table.pack(spawn(function(...)
+      return ...
+    end, table.unpack(args)):await())
+    assert(res.n == 1000 and res[1] == 1 and res[1000] == 1000)
+  end)
+
+  test("callback closes over upvalues", function()
+    local x = 42
+    local function f()
+      return x
+    end
+    assert(spawn(f):await() == 42)
+  end)
+
+  test("order is consistent", function()
+    -- all tasks spawned in one batch should be resumed in the spawn order
+    local tasks, nums = {}, {}
+    for i = 1, 10 do
+      table.insert(
+        tasks,
+        spawn(function()
+          table.insert(nums, i)
+        end)
+      )
+    end
+    for i = 10, 1, -1 do
+      tasks[i]:await()
+    end
+    assert(#nums == 10)
+    for i = 1, 10 do
+      assert(nums[i] == i)
+    end
+  end)
+
+  test("nested spawns", function()
+    local result = {}
+    local function inner()
+      table.insert(result, "inner")
+      return "done"
+    end
+    local function outer()
+      table.insert(result, "outer")
+      local v = spawn(inner):await()
+      table.insert(result, v)
+      return v
+    end
+    local v = spawn(outer):await()
+    assert(v == "done")
+    assert(result[1] == "outer" and result[2] == "inner" and result[3] == "done")
+  end)
+end)
+
+describe("sleep", function()
+  test("invalid arg", function()
+    assert(not pcall(task.sleep, "invalid"))
+    task.sleep(-1) -- negative sleep should just become 0ms
+  end)
+
+  test("sleep is asynchronous", function()
+    local value
+    spawn(function()
+      value = "value"
+    end)
+    assert(value == nil)
+    task.sleep(100) -- implicit await: if it's synchronous, value wouldn't change
+    assert(value == "value")
+  end)
+
+  test("sleep in nested spawns", function()
+    local value1, value2, value3 = nil, nil, nil
+    local results = {}
+    local function inner()
+      task.sleep(30)
+      value1 = "set by inner"
+      table.insert(results, "inner")
+      return value1
+    end
+    local function middle()
+      task.sleep(20)
+      value2 = "set by middle"
+      local v = spawn(inner):await()
+      table.insert(results, v)
+      table.insert(results, "middle")
+      return v, value2
+    end
+    local function outer()
+      task.sleep(10)
+      value3 = "set by outer"
+      local v1, v2 = spawn(middle):await()
+      table.insert(results, v1)
+      table.insert(results, v2)
+      table.insert(results, "outer")
+      return v1, v2, value3
+    end
+    assert(value1 == nil and value2 == nil and value3 == nil)
+    local r1, r2, r3 = spawn(outer):await()
+    assert(r1 == "set by inner" and r2 == "set by middle" and r3 == "set by outer")
+    assert(value1 == "set by inner" and value2 == "set by middle" and value3 == "set by outer")
+    assert(results[1] == "inner")
+    assert(results[2] == "set by inner")
+    assert(results[3] == "middle")
+    assert(results[4] == "set by inner")
+    assert(results[5] == "set by middle")
+    assert(results[6] == "outer")
+  end)
+end)
+
+describe("task", function()
+  test("properly unrefs arg and ret table", function()
+    local registry = debug.getregistry()
+    local ref, t
+    local cb = function()
+      return "my ret"
+    end
+    do
+      local task = spawn(cb, "my arg")
+      ref = task.__ref
+      t = registry[ref]
+      assert(type(t) == "table")
+      assert(t[1] == cb)
+      assert(t[2] == "my arg")
+      task:await()
+      assert(registry[task.__ref] == t)
+      assert(t[1] == "my ret")
+    end
+    collectgarbage()
+    assert(registry[ref] ~= t) -- if task unref'ed it, it should be either nil or the next freelist number
+  end)
+end)
--- a/crates/lb/tests/task.rs
+++ b/crates/lb/tests/task.rs
@@ -1,35 +0,0 @@
-use lb::runtime;
-use luaify::luaify;
-use luajit::{Chunk, LoadMode};
-use tokio::test;
-
-async fn run_lua(s: &'static str) {
-    let rt = runtime::Builder::new().build().unwrap();
-    let task = rt.spawn(async move |state| {
-        println!("executing test chunk: {s}");
-
-        state
-            .load(Chunk::new(s).mode(LoadMode::TEXT))
-            .unwrap_or_else(|err| panic!("{err}"));
-
-        state
-            .call_async(0, 0)
-            .await
-            .unwrap_or_else(|err| panic!("{err}"));
-    });
-
-    rt.await;
-    task.await.unwrap_or_else(|err| panic!("{err}"));
-}
-
-#[test]
-async fn task_test() {
-    run_lua(luaify!({
-        let thing = spawn(|| {
-            print("spawn callback!!!!!!!!!!!!!");
-        });
-        print("thing is", thing);
-        //
-    }))
-    .await
-}
--- a/crates/luaffi/Cargo.toml
+++ b/crates/luaffi/Cargo.toml
@@ -7,6 +7,10 @@ authors.workspace = true
 homepage.workspace = true
 repository.workspace = true

+[features]
+option_ref_abi = []
+option_string_abi = []
+
 [dependencies]
 bstr = "1.12.0"
 luaffi_impl = { path = "../luaffi_impl" }
--- a/crates/luaffi/src/future.rs
+++ b/crates/luaffi/src/future.rs
@@ -1,7 +1,7 @@
 use crate::{
    __internal::{display, type_id},
-    Cdef, CdefBuilder, FfiReturnConvention, IntoFfi, Metatype, MetatypeBuilder, Type, TypeBuilder,
-    TypeType, UnsafeExternCFn,
+    Cdef, CdefBuilder, ExternCFn, FfiReturnConvention, IntoFfi, Metatype, MetatypeBuilder, Type,
+    TypeBuilder, TypeType,
 };
 use luaify::luaify;
 use std::{
@@ -70,6 +70,45 @@ enum State<F: Future> {
    Complete,
 }

+unsafe impl<F: Future<Output: IntoFfi> + 'static> Type for lua_future<F> {
+    fn name() -> impl Display {
+        display!("__future_{:x}", type_id::<F>())
+    }
+
+    fn ty() -> TypeType {
+        TypeType::Aggregate
+    }
+
+    fn cdecl(name: impl Display) -> impl Display {
+        display!("struct {} {name}", Self::name())
+    }
+
+    fn build(s: &mut TypeBuilder) {
+        s.cdef::<Self>().metatype::<Self>();
+    }
+}
+
+unsafe impl<F: Future<Output: IntoFfi> + 'static> Cdef for lua_future<F> {
+    fn build(s: &mut CdefBuilder) {
+        s.field_opaque(mem::offset_of!(Self, take)) // opaque .sig, .poll and .state
+            .field::<ExternCFn<(&mut Self,), <F::Output as IntoFfi>::Into>>("__take")
+            .field::<ExternCFn<(&mut Self,), ()>>("__drop");
+    }
+}
+
+unsafe impl<F: Future<Output: IntoFfi> + 'static> Metatype for lua_future<F> {
+    type Target = Self;
+
+    fn build(s: &mut MetatypeBuilder) {
+        s.metatable_raw(
+            "gc",
+            luaify!(|self| {
+                self.__drop();
+            }),
+        );
+    }
+}
+
 impl<F: Future<Output: IntoFfi>> lua_future<F> {
    pub fn new(fut: F) -> Self {
        Self {
@@ -117,7 +156,12 @@ impl lua_pollable {
    pub fn is_valid(&self) -> bool {
        // TODO: signature check can currently read out-of-bounds if lua code for some reason yields
        // a cdata of size less than 8 bytes that is not a lua_future. there is no easy way to fix
-        // afaik this because there is no way to find the size of a cdata payload using the C API.
+        // AFAIK this because there is no way to find the size of a cdata payload using the C API.
+        // unfortunately we have to trust that the user won't do that right now.
+        //
+        // the only "saving grace" is that the user should never be running untrusted code anyway,
+        // because this whole project is based on the ffi library which should never be exposed to
+        // untrusted code in the first place.
        self.sig == SIGNATURE
    }
 }
@@ -131,40 +175,6 @@ impl Future for lua_pollable {
    }
 }

-unsafe impl<F: Future<Output: IntoFfi> + 'static> Type for lua_future<F> {
-    fn name() -> impl Display {
-        display!("future__{:x}", type_id::<F>())
-    }
-
-    fn ty() -> TypeType {
-        TypeType::Aggregate
-    }
-
-    fn cdecl(name: impl Display) -> impl Display {
-        display!("struct {} {name}", Self::name())
-    }
-
-    fn build(s: &mut TypeBuilder) {
-        s.cdef::<Self>().metatype::<Self>();
-    }
-}
-
-unsafe impl<F: Future<Output: IntoFfi> + 'static> Cdef for lua_future<F> {
-    fn build(s: &mut CdefBuilder) {
-        s.field_opaque(mem::offset_of!(Self, take)) // opaque .sig, .poll and .state
-            .field::<UnsafeExternCFn<(&mut Self,), <F::Output as IntoFfi>::Into>>("__take")
-            .field::<UnsafeExternCFn<(&mut Self,), ()>>("__drop");
-    }
-}
-
-unsafe impl<F: Future<Output: IntoFfi> + 'static> Metatype for lua_future<F> {
-    type Target = Self;
-
-    fn build(s: &mut MetatypeBuilder) {
-        s.metatable_raw("gc", luaify!(|self| self.__drop()));
-    }
-}
-
 unsafe impl<F: Future<Output: IntoFfi> + 'static> IntoFfi for lua_future<F> {
    type Into = lua_future<F>;

--- a/crates/luaffi/src/internal.rs
+++ b/crates/luaffi/src/internal.rs
@@ -6,23 +6,6 @@ use std::{
    hash::{Hash, Hasher},
 };

-#[allow(non_camel_case_types)]
-pub mod stub_types {
-    pub struct any;
-    pub struct nil;
-    pub struct boolean;
-    pub struct lightuserdata;
-    pub struct number;
-    pub struct integer;
-    pub struct string;
-    pub struct table;
-    pub struct function;
-    pub struct userdata;
-    pub struct thread;
-    pub struct cdata;
-    pub struct variadic;
-}
-
 pub fn type_id<T: 'static>() -> u64 {
    let mut hash = FxHasher::default();
    TypeId::of::<T>().hash(&mut hash);
--- a/crates/luaffi/src/lib.lua
+++ b/crates/luaffi/src/lib.lua
@@ -1,24 +1,22 @@
+---@diagnostic disable
 local LUA_REFNIL = -1 -- lib_aux.c
 local FREELIST_REF = 0

-local function __ref(value, t)
-  if value == nil then return LUA_REFNIL end
-  if t == nil then t = __registry end
-  local ref = t[FREELIST_REF]
+local function __ref(value)
+  if rawequal(value, nil) then return LUA_REFNIL end
+  local ref = __registry[FREELIST_REF]
  if ref ~= nil and ref ~= 0 then
-    t[FREELIST_REF] = t[ref]
+    __registry[FREELIST_REF] = __registry[ref]
  else
-    ref = #t + 1
+    ref = rawlen(__registry) + 1
  end
-  t[ref] = value
+  __registry[ref] = value
  return ref
 end

-local function __unref(ref, t)
-  if ref < 0 then return nil end
-  if t == nil then t = __registry end
-  local value = t[ref]
-  t[ref] = t[FREELIST_REF]
-  t[FREELIST_REF] = ref
-  return value
+local function __unref(ref)
+  if ref > 0 then
+    __registry[ref] = __registry[FREELIST_REF]
+    __registry[FREELIST_REF] = ref
+  end
 end
--- a/crates/luaffi/src/lib.rs
+++ b/crates/luaffi/src/lib.rs
@@ -3,21 +3,22 @@ use crate::{
    string::{DROP_BUFFER_FN, IS_UTF8_FN, lua_buffer},
 };
 pub use luaffi_impl::*;
+use rustc_hash::FxHashSet;
 use std::{
-    collections::HashSet,
    ffi::{c_double, c_float, c_void},
    fmt::{self, Display, Formatter, Write},
    marker::PhantomData,
    mem,
 };

-pub mod future;
-pub mod string;
-
 #[doc(hidden)]
 #[path = "./internal.rs"]
 pub mod __internal;
+pub mod future;
+pub mod marker;
+pub mod option;
 pub mod result;
+pub mod string;

 // Dummy function to ensure that strings passed to Rust via wrapper objects will not be
 // garbage-collected until the end of the function (used in string.rs when string marshalling is
@@ -25,8 +26,8 @@ pub mod result;
 // `ffi.keep(obj)`.
 //
 // https://github.com/LuaJIT/LuaJIT/issues/1167
-pub(crate) const KEEP_FN: &str = "luaffi_keep";
-#[unsafe(export_name = "luaffi_keep")]
+pub(crate) const KEEP_FN: &str = "__lf_keep";
+#[unsafe(export_name = "__lf_keep")]
 extern "C" fn __keep(_ptr: *const c_void) {}
 export![__keep];

@@ -38,7 +39,7 @@ const CACHE_LIBS: &[(&str, &str)] = &[
    ("package", "package"),
    ("debug", "debug"),
    ("jit", "jit"),
-    // require
+    // requires
    ("bit", r#"require("bit")"#),
    ("ffi", r#"require("ffi")"#),
    ("__tnew", r#"require("table.new")"#),
@@ -47,7 +48,7 @@ const CACHE_LIBS: &[(&str, &str)] = &[

 // https://www.lua.org/manual/5.1/manual.html#5.1
 const CACHE_LOCALS: &[(&str, &str)] = &[
-    // base
+    // baselib
    ("assert", "assert"),
    ("error", "error"),
    ("type", "type"),
@@ -68,7 +69,8 @@ const CACHE_LOCALS: &[(&str, &str)] = &[
    ("tonumber", "tonumber"),
    ("tostring", "tostring"),
    ("require", "require"),
-    // table
+    ("__yield", "coroutine.yield"), // (used in future.rs)
+    // tablib
    ("__tconcat", "table.concat"),
    ("__tinsert", "table.insert"),
    ("__tmaxn", "table.maxn"),
@@ -76,23 +78,21 @@ const CACHE_LOCALS: &[(&str, &str)] = &[
    ("__tsort", "table.sort"),
    ("__tpack", "table.pack"),
    ("__tunpack", "table.unpack"),
-    // string
+    // strlib
    ("__slen", "string.len"),
    ("__sprintf", "string.format"),
    ("__ssub", "string.sub"),
    ("__sgsub", "string.gsub"),
    ("__sgmatch", "string.gmatch"),
    ("__sdump", "string.dump"),
-    // math (used in luaify! macro)
+    // mathlib (used in luaify! macro)
    ("__fmod", "math.fmod"),
-    // coroutine (used in future.rs)
-    ("__yield", "coroutine.yield"),
-    // package
+    // loadlib
    ("__preload", "package.preload"),
-    // debug
+    // dblib
    ("__traceback", "debug.traceback"),
    ("__registry", "debug.getregistry()"), // (used in lib.lua)
-    // ffi
+    // ffilib
    ("__C", "ffi.C"),
    ("__ct", "{}"),
    ("__cdef", "ffi.cdef"),
@@ -105,7 +105,7 @@ const CACHE_LOCALS: &[(&str, &str)] = &[
    ("__sizeof", "ffi.sizeof"),
    ("__alignof", "ffi.alignof"),
    ("__intern", "ffi.string"), // (used in string.rs)
-    // bit (used in luaify! macro)
+    // bitlib (used in luaify! macro)
    ("__bnot", "bit.bnot"),
    ("__band", "bit.band"),
    ("__bor", "bit.bor"),
@@ -128,8 +128,8 @@ fn cache_local(f: &mut Formatter, list: &[(&str, &str)]) -> fmt::Result {

 #[derive(Debug, Clone, Default)]
 pub struct Registry {
-    types: HashSet<String>,
-    funcs: HashSet<String>,
+    types: FxHashSet<String>,
+    decls: FxHashSet<String>,
    cdef: String,
    lua: String,
 }
@@ -137,41 +137,41 @@ pub struct Registry {
 impl Registry {
    pub fn new() -> Self {
        let mut s = Self::default();
-        s.declare::<UnsafeExternCFn<(*const c_void,), ()>>(KEEP_FN);
-        s.declare::<UnsafeExternCFn<(*const u8, usize), bool>>(IS_UTF8_FN);
-        s.declare::<UnsafeExternCFn<(*mut lua_buffer,), ()>>(DROP_BUFFER_FN);
+        s.declare::<ExternCFn<(*const c_void,), ()>>(KEEP_FN);
+        s.declare::<ExternCFn<(*const u8, usize), bool>>(IS_UTF8_FN);
+        s.declare::<ExternCFn<(*mut lua_buffer,), ()>>(DROP_BUFFER_FN);
        s
    }

    pub fn include<T: Type>(&mut self) -> &mut Self {
        self.types
            .insert(T::name().to_string())
-            .then(|| T::build(&mut TypeBuilder::new::<T>(self)));
+            .then(|| T::build(&mut TypeBuilder::new(self)));
        self
    }

    pub fn declare<T: Type>(&mut self, name: impl Display) -> &mut Self {
        assert!(T::ty() != TypeType::Void, "cannot declare void type");
        self.include::<T>()
-            .funcs
-            .insert(name.to_string())
-            .then(|| writeln!(self.cdef, "{};", T::extern_cdecl(name)).unwrap());
+            .decls
+            .insert(T::extern_cdecl(&name).to_string())
+            .then(|| writeln!(self.cdef, "{};", T::extern_cdecl(&name)).unwrap());
        self
    }

-    pub fn preload<T: Type>(&mut self, name: impl Display) -> &mut Self {
+    pub fn preload<T: Module>(&mut self) -> &mut Self {
        assert!(T::ty() != TypeType::Void, "cannot declare void type");
-        self.include::<T>();
-        let ct = T::name();
+        let name = <T as Module>::name();
+        let ct = <T as Type>::name();
        writeln!(
            self.lua,
            r#"__preload["{name}"] = function(...) return __ct.{ct}(...); end;"#,
        )
        .unwrap();
-        self
+        self.include::<T>()
    }

-    pub fn done(&self) -> String {
+    pub fn build(&self) -> String {
        self.to_string()
    }
 }
@@ -184,7 +184,7 @@ impl Display for Registry {
        cache_local(f, CACHE_LIBS)?;
        cache_local(f, CACHE_LOCALS)?;
        writeln!(f, "{}", include_str!("./lib.lua"))?;
-        writeln!(f, "__cdef [[\n{}\n]];", self.cdef.trim())?;
+        writeln!(f, "__cdef [[\n{}\n]];", self.cdef.trim_end())?;
        write!(f, "{}", self.lua)
    }
 }
@@ -210,53 +210,49 @@ pub enum TypeType {

 #[derive(Debug)]
 pub struct TypeBuilder<'r> {
-    registry: &'r mut Registry,
+    reg: &'r mut Registry,
 }

 impl<'r> TypeBuilder<'r> {
-    fn new<T: Type>(registry: &'r mut Registry) -> Self {
-        let ct = T::name();
-        let cdecl = T::cdecl("");
-        writeln!(registry.lua, r#"__ct.{ct} = __typeof("{cdecl}");"#).unwrap();
-        Self { registry }
-    }
-
-    pub fn include<T: Type>(&mut self) -> &mut Self {
-        self.registry.include::<T>();
-        self
+    fn new(reg: &'r mut Registry) -> Self {
+        Self { reg }
    }

    pub fn cdef<T: Cdef>(&mut self) -> &mut Self {
-        let mut b = CdefBuilder::new::<T>(self.registry);
+        let mut b = CdefBuilder::new::<T>(self.reg);
        <T as Cdef>::build(&mut b);
        drop(b);
        self
    }

    pub fn metatype<T: Metatype>(&mut self) -> &mut Self {
-        let mut b = MetatypeBuilder::new::<T>(self.registry);
+        let mut b = MetatypeBuilder::new::<T>(self.reg);
        <T as Metatype>::build(&mut b);
        drop(b);
        self
    }
 }

+pub trait Module: Type {
+    fn name() -> impl Display;
+}
+
 pub unsafe trait Cdef: Type {
    fn build(b: &mut CdefBuilder);
 }

 #[derive(Debug)]
 pub struct CdefBuilder<'r> {
-    registry: &'r mut Registry,
+    reg: &'r mut Registry,
    cdef: String,
    align: usize,
    opaque: usize,
 }

 impl<'r> CdefBuilder<'r> {
-    fn new<T: Cdef>(registry: &'r mut Registry) -> Self {
+    fn new<T: Cdef>(reg: &'r mut Registry) -> Self {
        Self {
-            registry,
+            reg,
            cdef: format!("{} {{ ", T::cdecl("")),
            align: mem::align_of::<T>(),
            opaque: 0,
@@ -265,7 +261,7 @@ impl<'r> CdefBuilder<'r> {

    pub fn field<T: Type>(&mut self, name: impl Display) -> &mut Self {
        assert!(T::ty() != TypeType::Void, "cannot declare void field");
-        self.registry.include::<T>();
+        self.reg.include::<T>();
        self.field_raw(T::cdecl(name))
    }

@@ -299,14 +295,11 @@ impl<'r> CdefBuilder<'r> {
 impl<'r> Drop for CdefBuilder<'r> {
    fn drop(&mut self) {
        let Self {
-            registry,
-            cdef,
-            align,
-            ..
+            reg, cdef, align, ..
        } = self;

-        registry.cdef.push_str(cdef);
-        writeln!(registry.cdef, "}} __attribute__((aligned({align})));").unwrap();
+        reg.cdef.push_str(cdef);
+        writeln!(reg.cdef, "}} __attribute__((aligned({align})));").unwrap();
    }
 }

@@ -317,56 +310,73 @@ pub unsafe trait Metatype {

 #[derive(Debug)]
 pub struct MetatypeBuilder<'r> {
-    registry: &'r mut Registry,
+    reg: &'r mut Registry,
    ct: String,
    cdef: String,
    lua: String,
+    lua_includes: Vec<&'static str>,
+    has_index: bool,
 }

 impl<'r> MetatypeBuilder<'r> {
-    fn new<T: Metatype>(registry: &'r mut Registry) -> Self {
+    fn new<T: Metatype>(reg: &'r mut Registry) -> Self {
+        // NOTE: this needs to be written first, because recursively included dependency types might
+        // need it
+        let ct = T::Target::name();
+        let cdecl = T::Target::cdecl("");
+        writeln!(reg.lua, r#"__ct.{ct} = __typeof("{cdecl}");"#).unwrap();
+
        Self {
-            registry,
+            reg,
            ct: T::Target::name().to_string(),
            cdef: String::new(),
-            lua: r#"do local __mt, __idx = {}, {}; __mt.__index = __idx; "#.into(),
+            lua: String::new(),
+            lua_includes: vec![],
+            has_index: false,
        }
    }

    pub fn declare<T: Type>(&mut self, name: impl Display) -> &mut Self {
-        self.registry.declare::<T>(name);
+        self.reg.declare::<T>(name);
+        self
+    }
+
+    pub fn include_lua(&mut self, lua: &'static str) -> &mut Self {
+        self.lua_includes.push(lua);
        self
    }

    pub fn index(
        &mut self,
        name: impl Display,
-        f: impl FnOnce(&mut MetatypeMethodBuilder),
+        f: impl FnOnce(&mut MetatypeFunctionBuilder),
    ) -> &mut Self {
-        write!(self.lua, "__idx.{name} = ").unwrap();
-        f(&mut MetatypeMethodBuilder::new(self));
-        write!(self.lua, "; ").unwrap();
+        write!(self.lua, "Self.{name} = ").unwrap();
+        f(&mut MetatypeFunctionBuilder::new(self));
+        writeln!(self.lua, ";").unwrap();
+        self.has_index = true;
        self
    }

    pub fn index_raw(&mut self, name: impl Display, value: impl Display) -> &mut Self {
-        write!(self.lua, "__idx.{name} = {value}; ").unwrap();
+        writeln!(self.lua, "Self.{name} = {value};").unwrap();
+        self.has_index = true;
        self
    }

    pub fn metatable(
        &mut self,
        name: impl Display,
-        f: impl FnOnce(&mut MetatypeMethodBuilder),
+        f: impl FnOnce(&mut MetatypeFunctionBuilder),
    ) -> &mut Self {
        write!(self.lua, "__mt.__{name} = ").unwrap();
-        f(&mut MetatypeMethodBuilder::new(self));
-        write!(self.lua, "; ").unwrap();
+        f(&mut MetatypeFunctionBuilder::new(self));
+        writeln!(self.lua, ";").unwrap();
        self
    }

    pub fn metatable_raw(&mut self, name: impl Display, value: impl Display) -> &mut Self {
-        write!(self.lua, "__mt.__{name} = {value}; ").unwrap();
+        writeln!(self.lua, "__mt.__{name} = {value};").unwrap();
        self
    }
 }
@@ -374,16 +384,28 @@ impl<'r> MetatypeBuilder<'r> {
 impl<'r> Drop for MetatypeBuilder<'r> {
    fn drop(&mut self) {
        let Self {
-            registry,
+            reg,
            ct,
            cdef,
            lua,
-            ..
+            lua_includes,
+            has_index,
        } = self;

-        registry.cdef.push_str(cdef);
-        registry.lua.push_str(lua);
-        writeln!(registry.lua, r#"__metatype(__ct.{ct}, __mt); end;"#).unwrap();
+        write!(reg.lua, r#"do local __mt = {{}}; "#).unwrap();
+
+        if *has_index {
+            write!(reg.lua, r#"local Self = {{}}; __mt.__index = Self; "#).unwrap();
+        }
+
+        reg.cdef.push_str(cdef);
+        reg.lua.push_str(lua.trim_end());
+
+        writeln!(reg.lua, r#" __metatype(__ct.{ct}, __mt); end;"#).unwrap();
+
+        for lua in lua_includes {
+            writeln!(reg.lua, "do {}\nend;", lua.trim_end()).unwrap();
+        }
    }
 }

@@ -429,16 +451,17 @@ pub unsafe trait IntoFfi: Sized {
 }

 #[derive(Debug)]
-pub struct MetatypeMethodBuilder<'r, 'm> {
+pub struct MetatypeFunctionBuilder<'r, 'm> {
    metatype: &'m mut MetatypeBuilder<'r>,
-    lparams: String,  // parameters to the lua function
-    cparams: String,  // parameters to the lua function
-    cargs: String,    // arguments to the C call
-    prelude: String,  // function body prelude
-    postlude: String, // function body postlude
+    lparams: String,  // lua function parameters
+    cparams: String,  // C function parameters
+    cargs: String,    // C call arguments
+    prelude: String,  // lua function body prelude
+    postlude: String, // lua function body postlude
+    is_eqmm: bool,
 }

-impl<'r, 'm> MetatypeMethodBuilder<'r, 'm> {
+impl<'r, 'm> MetatypeFunctionBuilder<'r, 'm> {
    pub fn new(metatype: &'m mut MetatypeBuilder<'r>) -> Self {
        Self {
            metatype,
@@ -447,17 +470,18 @@ impl<'r, 'm> MetatypeMethodBuilder<'r, 'm> {
            cargs: String::new(),
            prelude: String::new(),
            postlude: String::new(),
+            is_eqmm: false,
        }
    }

+    pub fn set_eqmm(&mut self, eq: bool) -> &mut Self {
+        self.is_eqmm = eq; // are we building an __eq metamethod?
+        self
+    }
+
    pub fn param<T: FromFfi>(&mut self, name: impl Display) -> &mut Self {
-        assert!(
-            T::From::ty() != TypeType::Void,
-            "cannot declare void parameter"
-        );
-
        let Self {
-            metatype: MetatypeBuilder { registry, .. },
+            metatype: MetatypeBuilder { reg, .. },
            lparams,
            cparams,
            cargs,
@@ -466,7 +490,15 @@ impl<'r, 'm> MetatypeMethodBuilder<'r, 'm> {
            ..
        } = self;

-        registry.include::<T::From>();
+        assert!(
+            T::From::ty() != TypeType::Void,
+            "cannot declare void parameter"
+        );
+
+        // should already be prevented by #[metatype] macro
+        debug_assert!(!name.to_string().starts_with("__"));
+
+        reg.include::<T::From>();

        (!lparams.is_empty()).then(|| lparams.push_str(", "));
        (!cparams.is_empty()).then(|| cparams.push_str(", "));
@@ -485,6 +517,26 @@ impl<'r, 'm> MetatypeMethodBuilder<'r, 'm> {
        self
    }

+    pub fn param_ctchecked<T: FromFfi, U: Type + Metatype<Target = U>>(
+        &mut self,
+        name: impl Display,
+    ) -> &mut Self {
+        let ct = U::name();
+        if self.is_eqmm {
+            // special case for building __eq metamethods which are expected to return false if the
+            // arguments aren't of the expected type, because otherwise the `==` and `~=` operators
+            // could throw instead of returning false.
+            write!(
+                self.prelude,
+                r#"if not __istype(__ct.{ct}, {name}) then return false; end; "#
+            )
+        } else {
+            write!(self.prelude, r#"assert(__istype(__ct.{ct}, {name})); "#)
+        }
+        .unwrap();
+        self.param::<T>(name)
+    }
+
    pub fn param_str(
        &mut self,
        name: impl Display,
@@ -495,7 +547,9 @@ impl<'r, 'm> MetatypeMethodBuilder<'r, 'm> {
        //
        // this passes one lua `string` argument as two C `const uint8_t *ptr` and `uintptr_t len`
        // arguments, bypassing the slower generic `&[u8]: FromFfi` path which constructs a
-        // temporary cdata to pass the string and its length in one argument.
+        // temporary cdata to pass the string and its length in one argument. this is used when the
+        // #[metatype] macro detects a string-like parameter, currently defined to be &[u8], &str,
+        // &BStr (from the bstr crate), or those types wrapped in Option<T>.
        let Self {
            lparams,
            cparams,
@@ -504,6 +558,9 @@ impl<'r, 'm> MetatypeMethodBuilder<'r, 'm> {
            ..
        } = self;

+        // should already be prevented by #[metatype] macro
+        debug_assert!(!name.to_string().starts_with("__"));
+
        let param_ptr = <*const u8>::cdecl(&name);
        let param_len = usize::cdecl(format!("{name}_len"));

@@ -514,15 +571,22 @@ impl<'r, 'm> MetatypeMethodBuilder<'r, 'm> {
        write!(lparams, "{name}").unwrap();
        write!(cparams, "{param_ptr}, {param_len}").unwrap();
        write!(cargs, "{name}, __{name}_len").unwrap();
-        write!(prelude, "local __{name}_len = 0; if {name} ~= nil then ").unwrap();
+        write!(
+            prelude,
+            "local __{name}_len = 0; if not rawequal({name}, nil) then "
+        )
+        .unwrap();
        write!(prelude, r#"assert(type({name}) == "string", "string expected in argument '{name}', got " .. type({name})); "#).unwrap();
        write!(prelude, r#"__{name}_len = #{name}; "#).unwrap();
+
        if check_utf8 {
            write!(prelude, r#"assert(__C.{IS_UTF8_FN}({name}, __{name}_len), "argument '{name}' must be a valid utf-8 string"); "#).unwrap();
        }
+
        if !allow_nil {
            write!(prelude, r#"else return error("string expected in argument '{name}', got " .. type({name})); "#).unwrap();
        }
+
        write!(prelude, r#"end; "#).unwrap();
        self
    }
@@ -535,13 +599,7 @@ impl<'r, 'm> MetatypeMethodBuilder<'r, 'm> {

    pub fn call<T: IntoFfi>(&mut self, func: impl Display) {
        let Self {
-            metatype:
-                MetatypeBuilder {
-                    registry,
-                    cdef,
-                    lua,
-                    ..
-                },
+            metatype: MetatypeBuilder { reg, cdef, lua, .. },
            lparams,
            cparams,
            cargs,
@@ -550,7 +608,7 @@ impl<'r, 'm> MetatypeMethodBuilder<'r, 'm> {
            ..
        } = self;

-        registry.include::<T::Into>();
+        reg.include::<T::Into>();
        write!(lua, "function({lparams}) {prelude}").unwrap();

        match T::convention() {
@@ -558,22 +616,22 @@ impl<'r, 'm> MetatypeMethodBuilder<'r, 'm> {
                if T::Into::ty() == TypeType::Void {
                    write!(lua, "__C.{func}({cargs}); {postlude}end").unwrap();
                } else {
-                    let check = T::postlude("__ret");
-                    write!(lua, "local __ret = __C.{func}({cargs}); ").unwrap();
-                    write!(lua, "{check}{postlude}return __ret; end").unwrap();
+                    let check = T::postlude("ret");
+                    write!(lua, "local ret = __C.{func}({cargs}); ").unwrap();
+                    write!(lua, "{check}{postlude}return ret; end").unwrap();
                }

                writeln!(cdef, "{};", T::Into::cdecl(display!("{func}({cparams})"))).unwrap();
            }
            FfiReturnConvention::ByOutParam => {
                let ct = T::Into::name();
-                let check = T::postlude("__out");
-                write!(lua, "local __out = __new(__ct.{ct}); __C.{func}(__out").unwrap();
+                let check = T::postlude("__ret");
+                write!(lua, "local __ret = __new(__ct.{ct}); __C.{func}(__ret").unwrap();
                if !cargs.is_empty() {
                    write!(lua, ", {cargs}").unwrap();
                }
-                write!(lua, "); {check}{postlude}return __out; end").unwrap();
-                write!(cdef, "void {func}({}", <*mut T::Into>::cdecl("out")).unwrap();
+                write!(lua, "); {check}{postlude}return __ret; end").unwrap();
+                write!(cdef, "void {func}({}", <*mut T::Into>::cdecl("__out")).unwrap();
                if !cparams.is_empty() {
                    write!(cdef, ", {cparams}").unwrap();
                }
@@ -587,6 +645,10 @@ impl<'r, 'm> MetatypeMethodBuilder<'r, 'm> {
    }
 }

+pub trait Annotation {
+    fn annotation() -> impl Display;
+}
+
 //
 // SAFETY: Unit type return maps to a C void return, which is a nil return in lua. There is no
 // equivalent to passing a unit type as an argument in C.
@@ -620,7 +682,7 @@ impl_void!(());
 impl_void!(c_void);

 macro_rules! impl_primitive {
-    ($rty:ty, $cty:expr) => {
+    ($rty:ty, $cty:expr, $lty:expr) => {
        unsafe impl Type for $rty {
            fn name() -> impl Display {
                $cty
@@ -636,22 +698,28 @@ macro_rules! impl_primitive {

            fn build(_b: &mut TypeBuilder) {}
        }
+
+        impl Annotation for $rty {
+            fn annotation() -> impl Display {
+                $lty
+            }
+        }
    };
 }

-impl_primitive!(bool, "bool");
-impl_primitive!(u8, "uint8_t");
-impl_primitive!(u16, "uint16_t");
-impl_primitive!(u32, "uint32_t");
-impl_primitive!(u64, "uint64_t");
-impl_primitive!(usize, "uintptr_t");
-impl_primitive!(i8, "int8_t");
-impl_primitive!(i16, "int16_t");
-impl_primitive!(i32, "int32_t");
-impl_primitive!(i64, "int64_t");
-impl_primitive!(isize, "intptr_t");
-impl_primitive!(c_float, "float");
-impl_primitive!(c_double, "double");
+impl_primitive!(bool, "bool", "boolean");
+impl_primitive!(u8, "uint8_t", "number");
+impl_primitive!(u16, "uint16_t", "number");
+impl_primitive!(u32, "uint32_t", "number");
+impl_primitive!(u64, "uint64_t", "number");
+impl_primitive!(usize, "uintptr_t", "number");
+impl_primitive!(i8, "int8_t", "number");
+impl_primitive!(i16, "int16_t", "number");
+impl_primitive!(i32, "int32_t", "number");
+impl_primitive!(i64, "int64_t", "number");
+impl_primitive!(isize, "intptr_t", "number");
+impl_primitive!(c_float, "float", "number");
+impl_primitive!(c_double, "double", "number");

 unsafe impl FromFfi for bool {
    type From = bool;
@@ -741,8 +809,7 @@ macro_rules! impl_bigint_intoabi {
            fn postlude(ret: &str) -> impl Display {
                // this isn't "correct" per se, but it's much more ergonomic to work with numbers in
                // lua than with long longs wrapped in cdata. we gracefully accept the loss of
-                // precision here and that 53 bits of precision for big integers are enough. (the
-                // vain of Lua 5.3 integer subtype ;D )
+                // precision here and that 53 bits of precision for big integers are enough.
                display!("{ret} = tonumber({ret}); ")
            }
        }
@@ -756,11 +823,19 @@ impl_bigint_intoabi!(usize);
 #[cfg(target_pointer_width = "64")]
 impl_bigint_intoabi!(isize);

-macro_rules! impl_const_ptr {
-    ($ty:ty) => {
-        unsafe impl<T: Type> Type for $ty {
+macro_rules! impl_ptr {
+    ($ty:ty, $mutable:expr) => {
+        unsafe impl<T> Type for $ty
+        where
+            T: Type,
+        {
            fn name() -> impl Display {
-                display!("const_{}_ptr", T::name())
+                disp(|f| {
+                    if !$mutable {
+                        write!(f, "const_")?;
+                    }
+                    write!(f, "{}_ptr", T::name())
+                })
            }

            fn ty() -> TypeType {
@@ -768,45 +843,43 @@ macro_rules! impl_const_ptr {
            }

            fn cdecl(name: impl Display) -> impl Display {
-                T::cdecl(display!("const *{name}"))
+                T::cdecl(disp(move |f| {
+                    if !$mutable {
+                        write!(f, "const ")?;
+                    }
+                    write!(f, "*{name}")
+                }))
            }

            fn build(b: &mut TypeBuilder) {
-                b.include::<T>();
+                b.reg.include::<T>();
            }
        }
    };
 }

-impl_const_ptr!(*const T);
-impl_const_ptr!(&T);
-impl_const_ptr!(Option<&T>);
+impl_ptr!(&T, false);
+impl_ptr!(&mut T, true);
+impl_ptr!(*const T, false);
+impl_ptr!(*mut T, true);
+impl_ptr!(Option<&T>, false);
+impl_ptr!(Option<&mut T>, true);

-macro_rules! impl_mut_ptr {
+macro_rules! impl_ref_annotation {
    ($ty:ty) => {
-        unsafe impl<T: Type> Type for $ty {
-            fn name() -> impl Display {
-                display!("{}_ptr", T::name())
-            }
-
-            fn ty() -> TypeType {
-                TypeType::Primitive
-            }
-
-            fn cdecl(name: impl Display) -> impl Display {
-                T::cdecl(display!("*{name}"))
-            }
-
-            fn build(b: &mut TypeBuilder) {
-                b.include::<T>();
+        impl<T> Annotation for $ty
+        where
+            T: Annotation,
+        {
+            fn annotation() -> impl Display {
+                display!("{}", T::annotation())
            }
        }
    };
 }

-impl_mut_ptr!(*mut T);
-impl_mut_ptr!(&mut T);
-impl_mut_ptr!(Option<&mut T>);
+impl_ref_annotation!(&T);
+impl_ref_annotation!(&mut T);

 //
 // SAFETY: Pass by value for pointers, which maps to a `cdata` argument in lua containing either:
@@ -819,7 +892,10 @@ impl_mut_ptr!(Option<&mut T>);
 //
 macro_rules! impl_ptr_fromabi {
    ($ty:ty) => {
-        unsafe impl<T: Type> FromFfi for $ty {
+        unsafe impl<T> FromFfi for $ty
+        where
+            T: Type,
+        {
            type From = Self;

            fn convert(from: Self::From) -> Self {
@@ -841,7 +917,10 @@ impl_ptr_fromabi!(Option<&mut T>);
 //
 macro_rules! impl_ptr_intoabi {
    ($ty:ty) => {
-        unsafe impl<T: Type> IntoFfi for $ty {
+        unsafe impl<T> IntoFfi for $ty
+        where
+            T: Type,
+        {
            type Into = Self;

            fn convert(self) -> Self::Into {
@@ -857,34 +936,19 @@ macro_rules! impl_ptr_intoabi {

 impl_ptr_intoabi!(*const T);
 impl_ptr_intoabi!(*mut T);
+#[cfg(feature = "option_ref_abi")] // disabled because it conflicts with the generic Option<T> impl
 impl_ptr_intoabi!(Option<&'static T>);
+#[cfg(feature = "option_ref_abi")]
 impl_ptr_intoabi!(Option<&'static mut T>);

-//
-// SAFETY: `FromFfi` for *mutable* references is safe because it is guaranteed that no two Rust code
-// called via FFI can be running at the same time on the same OS thread (no Lua reentrancy).
-//
-// i.e. The call stack will always look something like this:
-//
-// * Runtime (LuaJIT/Rust) -> Lua (via C) -> Rust (via FFI): This is SAFE and the only use case we
-//     support. All references (mutable or not) to Rust user objects will be dropped before
-//     returning to Lua.
-//
-// * Runtime (LuaJIT/Rust) -> Lua (via C) -> Rust (via FFI) -> Lua (via callback): This is UNSAFE
-//     because we cannot prevent the Lua callback from calling back into Rust code via FFI which
-//     could violate exclusive borrow semantics. This is prevented by not implementing `FromFfi` for
-//     function pointers (see below).
-//
-// The runtime does not keep any references to Rust user objects boxed in cdata (futures are the
-// only exception; their ownership is transferred to the runtime via yield).
-//
-macro_rules! impl_ref_fromabi {
-    ($ty:ty) => {
-        unsafe impl<'s, T: Type> FromFfi for $ty {
-            type From = Option<$ty>;
+unsafe impl<'s, T> FromFfi for &'s T
+where
+    T: Type,
+{
+    type From = Option<&'s T>;

    fn prelude(arg: &str) -> impl Display {
-                display!(r#"assert({arg} ~= nil, "argument '{arg}' cannot be nil"); "#)
+        display!(r#"assert(not rawequal({arg}, nil), "argument '{arg}' cannot be nil"); "#)
    }

    fn convert(from: Self::From) -> Self {
@@ -898,30 +962,21 @@ macro_rules! impl_ref_fromabi {
        unsafe { from.unwrap_unchecked() }
    }
 }
-    };
-}
-
-impl_ref_fromabi!(&'s T);
-impl_ref_fromabi!(&'s mut T);

 //
 // SAFETY: `IntoFfi` only for 'static references because we cannot guarantee that the pointer will
 // not outlive the pointee otherwise.
 //
-macro_rules! impl_ref_intoabi {
-    ($ty:ty) => {
-        unsafe impl<T: Type> IntoFfi for $ty {
+unsafe impl<T> IntoFfi for &'static T
+where
+    T: Type,
+{
    type Into = Self;

    fn convert(self) -> Self::Into {
        self
    }
 }
-    };
-}
-
-impl_ref_intoabi!(&'static T);
-impl_ref_intoabi!(&'static mut T);

 //
 // SAFETY: No `FromFfi` and `IntoFfi` for arrays because passing or returning them by value is not a
@@ -929,7 +984,10 @@ impl_ref_intoabi!(&'static mut T);
 //
 // TODO: we could automatically convert them to tables and vice-versa
 //
-unsafe impl<T: Type> Type for [T] {
+unsafe impl<T> Type for [T]
+where
+    T: Type,
+{
    fn name() -> impl Display {
        display!("{}_arr", T::name())
    }
@@ -943,11 +1001,23 @@ unsafe impl<T: Type> Type for [T] {
    }

    fn build(b: &mut TypeBuilder) {
-        b.include::<T>();
+        b.reg.include::<T>();
    }
 }

-unsafe impl<T: Type, const N: usize> Type for [T; N] {
+impl<T> Annotation for [T]
+where
+    T: Annotation,
+{
+    fn annotation() -> impl Display {
+        display!("{}[]", T::annotation())
+    }
+}
+
+unsafe impl<T, const N: usize> Type for [T; N]
+where
+    T: Type,
+{
    fn name() -> impl Display {
        display!("{}_arr{N}", T::name())
    }
@@ -961,26 +1031,32 @@ unsafe impl<T: Type, const N: usize> Type for [T; N] {
    }

    fn build(b: &mut TypeBuilder) {
-        b.include::<T>();
+        b.reg.include::<T>();
    }
 }

-pub struct UnsafeExternCFn<In, Out>(PhantomData<unsafe extern "C" fn(In) -> Out>);
+impl<T, const N: usize> Annotation for [T; N]
+where
+    T: Annotation,
+{
+    fn annotation() -> impl Display {
+        display!("{}[]", T::annotation())
+    }
+}

-macro_rules! impl_function {
-    (fn($($arg:tt),*) -> $ret:tt) => {
-        impl_function!(UnsafeExternCFn, fn($($arg),*) -> $ret);
+pub struct ExternCFn<I, O>(PhantomData<extern "C" fn(I) -> O>);
+
+macro_rules! impl_externcfn {
+    (fn($($arg:ident),*) -> $ret:ident) => {
+        impl_externcfn!(ExternCFn, fn($($arg),*) -> $ret);
    };

-    ($ty:tt, fn($($arg:tt),*) -> $ret:tt) => {
-        //
-        // SAFETY: No `FromFfi` for function pointers because of borrow safety invariants (see above
-        // in `&mut T`).
-        //
-        // We also can't implement `IntoFfi` because we can't call `FromFfi` and `IntoFfi` for the
-        // function's respective argument and return values.
-        //
-        unsafe impl<$($arg: Type,)* $ret: Type> Type for $ty<($($arg,)*), $ret> {
+    ($ty:ident, fn($($arg:ident),*) -> $ret:ident) => {
+        unsafe impl<$($arg,)* $ret> Type for $ty<($($arg,)*), $ret>
+        where
+            $($arg: Type,)*
+            $ret: Type,
+        {
            fn name() -> impl Display {
                disp(|f| Ok({
                    write!(f, "fn_{}", $ret::name())?;
@@ -994,8 +1070,8 @@ macro_rules! impl_function {

            fn cdecl(name: impl Display) -> impl Display {
                $ret::cdecl(disp(move |f| Ok({
-                    let mut _n = 0;
                    write!(f, "(*{name})(")?;
+                    let mut _n = 0;
                    $(if _n != 0 { write!(f, ", ")?; } write!(f, "{}", $arg::cdecl(""))?; _n += 1;)*
                    write!(f, ")")?;
                })))
@@ -1004,26 +1080,52 @@ macro_rules! impl_function {
            fn extern_cdecl(name: impl Display) -> impl Display {
                $ret::cdecl(disp(move |f| Ok({
                    // for top-level function declarations in cdef
-                    let mut _n = 0;
                    write!(f, "{name}(")?;
+                    let mut _n = 0;
                    $(if _n != 0 { write!(f, ", ")?; } write!(f, "{}", $arg::cdecl(""))?; _n += 1;)*
                    write!(f, ")")?;
                })))
            }

            fn build(b: &mut TypeBuilder) {
-                $(b.include::<$arg>();)*
-                b.include::<$ret>();
+                $(b.reg.include::<$arg>();)*
+                b.reg.include::<$ret>();
            }
        }
    };
 }

-impl_function!(fn() -> Z);
-impl_function!(fn(A) -> Z);
-impl_function!(fn(A, B) -> Z);
-impl_function!(fn(A, B, C) -> Z);
-impl_function!(fn(A, B, C, D) -> Z);
-impl_function!(fn(A, B, C, D, E) -> Z);
-impl_function!(fn(A, B, C, D, E, F) -> Z);
-impl_function!(fn(A, B, C, D, E, F, G) -> Z);
+impl_externcfn!(fn() -> A);
+impl_externcfn!(fn(A) -> B);
+impl_externcfn!(fn(A, B) -> C);
+impl_externcfn!(fn(A, B, C) -> D);
+impl_externcfn!(fn(A, B, C, D) -> E);
+impl_externcfn!(fn(A, B, C, D, E) -> F);
+impl_externcfn!(fn(A, B, C, D, E, F) -> G);
+impl_externcfn!(fn(A, B, C, D, E, F, G) -> H);
+impl_externcfn!(fn(A, B, C, D, E, F, G, H) -> I);
+impl_externcfn!(fn(A, B, C, D, E, F, G, H, I) -> J);
+
+impl<'s> Annotation for &'s [u8] {
+    fn annotation() -> impl Display {
+        "string"
+    }
+}
+
+impl<'s> Annotation for &'s str {
+    fn annotation() -> impl Display {
+        "string"
+    }
+}
+
+impl Annotation for Vec<u8> {
+    fn annotation() -> impl Display {
+        "string"
+    }
+}
+
+impl Annotation for String {
+    fn annotation() -> impl Display {
+        "string"
+    }
+}
--- a/crates/luaffi/src/marker.rs
+++ b/crates/luaffi/src/marker.rs
@@ -0,0 +1,193 @@
+#![allow(non_camel_case_types)]
+use crate::{
+    __internal::{disp, display},
+    Annotation,
+};
+use std::{fmt::Display, marker::PhantomData};
+
+enum Marker {}
+
+pub struct any(Marker);
+
+impl Annotation for any {
+    fn annotation() -> impl Display {
+        "any"
+    }
+}
+
+pub struct many(Marker);
+
+impl Annotation for many {
+    fn annotation() -> impl Display {
+        "..."
+    }
+}
+
+pub struct nil(Marker);
+
+impl Annotation for nil {
+    fn annotation() -> impl Display {
+        "nil"
+    }
+}
+
+pub struct lightuserdata(Marker);
+
+impl Annotation for lightuserdata {
+    fn annotation() -> impl Display {
+        "lightuserdata"
+    }
+}
+
+pub struct table<K, V>(Marker, PhantomData<*mut [(K, V)]>);
+
+impl<K, V> Annotation for table<K, V>
+where
+    K: Annotation,
+    V: Annotation,
+{
+    fn annotation() -> impl Display {
+        display!("table<{}, {}>", K::annotation(), V::annotation())
+    }
+}
+
+pub struct function(Marker);
+
+impl Annotation for function {
+    fn annotation() -> impl Display {
+        "function"
+    }
+}
+
+pub struct fun<I, O>(Marker, PhantomData<fn(I) -> O>);
+
+macro_rules! impl_fun {
+    (fn($($arg:ident),*)) => {
+        impl<$($arg,)*> Annotation for fun<($($arg,)*), ()>
+        where
+            $($arg: Annotation,)*
+        {
+            fn annotation() -> impl Display {
+                disp(|f| {
+                    write!(f, "fun(")?;
+                    let mut _n = 0;
+                    $(if _n != 0 { write!(f, ", ")?; } write!(f, "{}", $arg::annotation())?; _n += 1;)*
+                    write!(f, ")")
+                })
+            }
+        }
+    };
+
+    (fn($($arg:ident),*) -> $ret:ident) => {
+        impl<$($arg,)* $ret> Annotation for fun<($($arg,)*), $ret>
+        where
+            $($arg: Annotation,)*
+            $ret: Annotation,
+        {
+            fn annotation() -> impl Display {
+                disp(|f| {
+                    write!(f, "fun(")?;
+                    let mut _n = 0;
+                    $(if _n != 0 { write!(f, ", ")?; } write!(f, "{}", $arg::annotation())?; _n += 1;)*
+                    write!(f, "): {}", $ret::annotation())
+                })
+            }
+        }
+
+        impl_fun!(fn($($arg),*));
+    };
+}
+
+impl_fun!(fn() -> A);
+impl_fun!(fn(A) -> B);
+impl_fun!(fn(A, B) -> C);
+impl_fun!(fn(A, B, C) -> D);
+impl_fun!(fn(A, B, C, D) -> E);
+impl_fun!(fn(A, B, C, D, E) -> F);
+impl_fun!(fn(A, B, C, D, E, F) -> G);
+impl_fun!(fn(A, B, C, D, E, F, G) -> H);
+impl_fun!(fn(A, B, C, D, E, F, G, H) -> I);
+impl_fun!(fn(A, B, C, D, E, F, G, H, I) -> J);
+
+pub struct userdata(Marker);
+
+impl Annotation for userdata {
+    fn annotation() -> impl Display {
+        "userdata"
+    }
+}
+
+pub struct thread(Marker);
+
+impl Annotation for thread {
+    fn annotation() -> impl Display {
+        "thread"
+    }
+}
+
+pub struct cdata(Marker);
+
+impl Annotation for cdata {
+    fn annotation() -> impl Display {
+        "cdata"
+    }
+}
+
+pub struct Either<T, U>(Marker, PhantomData<(T, U)>);
+
+impl<T, U> Annotation for Either<T, U>
+where
+    T: Annotation,
+    U: Annotation,
+{
+    fn annotation() -> impl Display {
+        display!("({} | {})", T::annotation(), U::annotation())
+    }
+}
+
+pub struct OneOf<X>(Marker, PhantomData<X>);
+
+macro_rules! impl_oneof {
+    ($($ty:ident),+) => {
+        impl<$($ty),+> Annotation for OneOf<($($ty,)+)>
+        where
+            $($ty: Annotation),+
+        {
+            fn annotation() -> impl Display {
+                disp(|f| {
+                    write!(f, "(")?;
+                    let mut _n = 0;
+                    $(if _n != 0 { write!(f, " | ")?; } write!(f, "{}", $ty::annotation())?; _n += 1;)*
+                    write!(f, ")")
+                })
+            }
+        }
+    };
+}
+
+impl_oneof!(A, B);
+impl_oneof!(A, B, C);
+impl_oneof!(A, B, C, D);
+impl_oneof!(A, B, C, D, E);
+impl_oneof!(A, B, C, D, E, F);
+impl_oneof!(A, B, C, D, E, F, G);
+impl_oneof!(A, B, C, D, E, F, G, H);
+impl_oneof!(A, B, C, D, E, F, G, H, I);
+
+impl<T> Annotation for Option<T>
+where
+    T: Annotation,
+{
+    fn annotation() -> impl Display {
+        display!("{}?", T::annotation())
+    }
+}
+
+impl<T, E> Annotation for Result<T, E>
+where
+    T: Annotation,
+{
+    fn annotation() -> impl Display {
+        display!("{}", T::annotation())
+    }
+}
--- a/crates/luaffi/src/option.rs
+++ b/crates/luaffi/src/option.rs
@@ -0,0 +1,89 @@
+use crate::{
+    __internal::{disp, display, type_id},
+    Cdef, CdefBuilder, IntoFfi, KEEP_FN, Metatype, MetatypeBuilder, Type, TypeBuilder, TypeType,
+};
+use std::{ffi::c_int, fmt::Display};
+
+#[repr(C)]
+#[allow(non_camel_case_types)]
+pub enum lua_option<T> {
+    None,    // __tag = 0
+    Some(T), // __tag = 1
+}
+
+unsafe impl<T: Type + 'static> Type for lua_option<T> {
+    fn name() -> impl Display {
+        display!("__option_{:x}", type_id::<T>())
+    }
+
+    fn ty() -> TypeType {
+        TypeType::Aggregate
+    }
+
+    fn cdecl(name: impl Display) -> impl Display {
+        display!("struct {} {name}", Self::name())
+    }
+
+    fn build(b: &mut TypeBuilder) {
+        b.cdef::<Self>().metatype::<Self>();
+    }
+}
+
+unsafe impl<T: Type + 'static> Cdef for lua_option<T> {
+    fn build(b: &mut CdefBuilder) {
+        b.field::<c_int>("__tag");
+        (T::ty() != TypeType::Void).then(|| b.field::<T>("__value"));
+    }
+}
+
+unsafe impl<T: Type + 'static> Metatype for lua_option<T> {
+    type Target = Self;
+    fn build(_b: &mut MetatypeBuilder) {}
+}
+
+unsafe impl<T: IntoFfi<Into: 'static>> IntoFfi for Option<T> {
+    type Into = lua_option<T::Into>;
+
+    fn convert(self) -> Self::Into {
+        match self {
+            Some(value) => lua_option::Some(T::convert(value)),
+            None => lua_option::None,
+        }
+    }
+
+    fn require_owned() -> bool {
+        // lua_option is only used to transmit information about whether we have a value or not and
+        // is forgotten immediately after use, so there is no need for an owned option
+        false
+    }
+
+    fn postlude(ret: &str) -> impl Display {
+        disp(move |f| {
+            write!(f, "if {ret}.__tag ~= 0 then ")?;
+            match T::Into::ty() {
+                TypeType::Void => write!(f, "{ret} = nil; ")?, // for void options, we don't have a __value
+                TypeType::Primitive => {
+                    // can always copy primitives to stack
+                    write!(f, "{ret} = {ret}.__value; {}", T::postlude(ret))?;
+                }
+                TypeType::Aggregate => {
+                    let ct = T::Into::name();
+                    if T::require_owned() {
+                        // inner value requires ownership; copy it into its own cdata and forget
+                        // option.
+                        write!(f, "{ret} = __new(__ct.{ct}, {ret}.__value); ")?;
+                        write!(f, "{}", T::postlude(ret))?;
+                    } else {
+                        // inner value is a "temporary" like an option itself and doesn't require
+                        // full ownership of itself. we just need to keep the option object alive
+                        // until its postlude completes.
+                        write!(f, "local {ret}_keep = {ret}; {ret} = {ret}.__value; ")?;
+                        write!(f, "do {}end; ", T::postlude(ret))?;
+                        write!(f, "__C.{KEEP_FN}({ret}_keep); ")?; // keep original option alive
+                    }
+                }
+            }
+            write!(f, "else {ret} = nil; end; ")
+        })
+    }
+}
--- a/crates/luaffi/src/result.rs
+++ b/crates/luaffi/src/result.rs
@@ -1,6 +1,6 @@
 use crate::{
-    __internal::{disp, display},
-    Cdef, CdefBuilder, IntoFfi, KEEP_FN, Type, TypeBuilder, TypeType,
+    __internal::{disp, display, type_id},
+    Cdef, CdefBuilder, IntoFfi, KEEP_FN, Metatype, MetatypeBuilder, Type, TypeBuilder, TypeType,
    string::{DROP_BUFFER_FN, lua_buffer},
 };
 use std::{ffi::c_int, fmt::Display};
@@ -12,9 +12,9 @@ pub enum lua_result<T> {
    Ok(T),           // __tag = 1
 }

-unsafe impl<T: Type> Type for lua_result<T> {
+unsafe impl<T: Type + 'static> Type for lua_result<T> {
    fn name() -> impl Display {
-        display!("result__{}", T::name())
+        display!("__result_{:x}", type_id::<T>())
    }

    fn ty() -> TypeType {
@@ -26,11 +26,11 @@ unsafe impl<T: Type> Type for lua_result<T> {
    }

    fn build(b: &mut TypeBuilder) {
-        b.cdef::<Self>();
+        b.cdef::<Self>().metatype::<Self>();
    }
 }

-unsafe impl<T: Type> Cdef for lua_result<T> {
+unsafe impl<T: Type + 'static> Cdef for lua_result<T> {
    fn build(b: &mut CdefBuilder) {
        b.field::<c_int>("__tag").inner_union(|b| {
            (T::ty() != TypeType::Void).then(|| b.field::<T>("__value"));
@@ -39,7 +39,12 @@ unsafe impl<T: Type> Cdef for lua_result<T> {
    }
 }

-unsafe impl<T: IntoFfi, E: Display> IntoFfi for Result<T, E> {
+unsafe impl<T: Type + 'static> Metatype for lua_result<T> {
+    type Target = Self;
+    fn build(_b: &mut MetatypeBuilder) {}
+}
+
+unsafe impl<T: IntoFfi<Into: 'static>, E: Display> IntoFfi for Result<T, E> {
    type Into = lua_result<T::Into>;

    fn convert(self) -> Self::Into {
@@ -72,12 +77,12 @@ unsafe impl<T: IntoFfi, E: Display> IntoFfi for Result<T, E> {
                        write!(f, "{ret} = __new(__ct.{ct}, {ret}.__value); ")?;
                        write!(f, "{}", T::postlude(ret))?;
                    } else {
-                        // inner value is a "temporary" itself and doesn't require full ownership of
-                        // itself. we just need to keep the result object alive until its postlude
-                        // completes.
-                        write!(f, "local __{ret} = {ret}; {ret} = {ret}.__value; ")?;
+                        // inner value is a "temporary" like a result itself and doesn't require
+                        // full ownership of itself. we just need to keep the result object alive
+                        // until its postlude completes.
+                        write!(f, "local {ret}_keep = {ret}; {ret} = {ret}.__value; ")?;
                        write!(f, "do {}end; ", T::postlude(ret))?;
-                        write!(f, "__C.{KEEP_FN}(__{ret}); ")?; // keep original result alive
+                        write!(f, "__C.{KEEP_FN}({ret}_keep); ")?; // keep original result alive
                    }
                }
            }
--- a/crates/luaffi/src/string.rs
+++ b/crates/luaffi/src/string.rs
@@ -4,18 +4,18 @@ use crate::{
 };
 use bstr::{BStr, BString};
 use luaffi_impl::{cdef, metatype};
-use std::{fmt::Display, mem::ManuallyDrop, ptr, slice};
+use std::{fmt::Display, mem::ManuallyDrop, slice};

-pub(crate) const IS_UTF8_FN: &str = "luaffi_is_utf8";
-pub(crate) const DROP_BUFFER_FN: &str = "luaffi_drop_buffer";
+pub(crate) const IS_UTF8_FN: &str = "__lf_is_utf8";
+pub(crate) const DROP_BUFFER_FN: &str = "__lf_drop_buffer";

-#[unsafe(export_name = "luaffi_is_utf8")]
+#[unsafe(export_name = "__lf_is_utf8")]
 unsafe extern "C" fn __is_utf8(ptr: *const u8, len: usize) -> bool {
    debug_assert!(!ptr.is_null());
    simdutf8::basic::from_utf8(unsafe { slice::from_raw_parts(ptr, len) }).is_ok()
 }

-#[unsafe(export_name = "luaffi_drop_buffer")]
+#[unsafe(export_name = "__lf_drop_buffer")]
 unsafe extern "C" fn __drop_buffer(buf: *mut lua_buffer) {
    debug_assert!(!buf.is_null());
    debug_assert!(!unsafe { (*buf).__ptr.is_null() });
@@ -42,6 +42,7 @@ impl lua_buf {
        }
    }

+    #[cfg(feature = "option_string_abi")]
    pub(crate) fn null() -> Self {
        Self {
            __ptr: ptr::null(),
@@ -71,6 +72,7 @@ impl lua_buffer {
        }
    }

+    #[cfg(feature = "option_string_abi")]
    pub(crate) fn null() -> Self {
        Self {
            __ptr: ptr::null_mut(),
@@ -228,6 +230,13 @@ impl_into_via!(&'static str, &'static BStr);
 impl_into_via!(BString, Vec<u8>);
 impl_into_via!(String, BString);

+// `Option<String>: From/IntoFfi` isn't implemented because it conflicts with the generic
+// `Option<T>: From/IntoFfi` impl and rust doesn't have specialisation yet (and probably not anytime
+// soon). this is fine for now because we have specialisation for string-like parameters implemented
+// in the #[metatype] macro already, and string returns wrapped in `Option<T>` isn't much additional
+// overhead.
+#[cfg(feature = "option_string_abi")]
+mod impl_option_string {
    macro_rules! impl_optional_from {
        ($ty:ty) => {
            unsafe impl<'s> FromFfi for Option<$ty> {
@@ -281,3 +290,4 @@ impl_optional_into!(&'static str, lua_buf::null());
    impl_optional_into!(Vec<u8>, lua_buffer::null());
    impl_optional_into!(BString, lua_buffer::null());
    impl_optional_into!(String, lua_buffer::null());
+}
--- a/crates/luaffi_impl/src/cdef.rs
+++ b/crates/luaffi_impl/src/cdef.rs
@@ -5,18 +5,26 @@ use quote::{format_ident, quote, quote_spanned};
 use syn::{ext::IdentExt, spanned::Spanned, *};

 #[derive(Debug, FromMeta)]
-pub struct Args {}
+pub struct Args {
+    module: Option<String>,
+}

-pub fn transform(_args: Args, mut item: Item) -> Result<TokenStream> {
-    let (name, impl_type, impl_cdef) = match item {
+pub fn transform(args: Args, mut item: Item) -> Result<TokenStream> {
+    let (name, impl_type, impl_module, impl_cdef) = match item {
        Item::Struct(ref mut str) => (
            str.ident.clone(),
            generate_type(&str.ident)?,
+            args.module
+                .map(|name| generate_module(&name, &str.ident))
+                .transpose()?,
            generate_cdef_structure(str)?,
        ),
        Item::Enum(ref mut enu) => (
            enu.ident.clone(),
            generate_type(&enu.ident)?,
+            args.module
+                .map(|name| generate_module(&name, &enu.ident))
+                .transpose()?,
            generate_cdef_enum(enu)?,
        ),
        _ => syn_error!(item, "expected struct or enum"),
@@ -24,7 +32,7 @@ pub fn transform(_args: Args, mut item: Item) -> Result<TokenStream> {

    let mod_name = format_ident!("__{name}_cdef");

-    Ok(quote_spanned!(name.span() =>
+    Ok(quote!(
        #[repr(C)]
        #[allow(non_camel_case_types)]
        #item
@@ -35,6 +43,7 @@ pub fn transform(_args: Args, mut item: Item) -> Result<TokenStream> {
        mod #mod_name {
            use super::*;
            #impl_type
+            #impl_module
            #impl_cdef
        }
    ))
@@ -42,14 +51,11 @@ pub fn transform(_args: Args, mut item: Item) -> Result<TokenStream> {

 fn generate_type(ty: &Ident) -> Result<TokenStream> {
    let ffi = ffi_crate();
-    let span = ty.span();
-    let name = LitStr::new(&ty.unraw().to_string(), span);
+    let name = ty.unraw().to_string();

-    Ok(quote_spanned!(span =>
+    Ok(quote!(
        unsafe impl #ffi::Type for #ty {
-            fn name() -> impl ::std::fmt::Display {
-                #name
-            }
+            fn name() -> impl ::std::fmt::Display { #name }

            fn ty() -> #ffi::TypeType {
                #ffi::TypeType::Aggregate
@@ -64,6 +70,10 @@ fn generate_type(ty: &Ident) -> Result<TokenStream> {
            }
        }

+        impl #ffi::Annotation for #ty {
+            fn annotation() -> impl ::std::fmt::Display { #name }
+        }
+
        // SAFETY: we can always implement `IntoFfi` because it transfers ownership from Rust to Lua
        unsafe impl #ffi::IntoFfi for #ty {
            type Into = Self;
@@ -72,6 +82,16 @@ fn generate_type(ty: &Ident) -> Result<TokenStream> {
    ))
 }

+fn generate_module(name: &str, ty: &Ident) -> Result<TokenStream> {
+    let ffi = ffi_crate();
+
+    Ok(quote!(
+        impl #ffi::Module for #ty {
+            fn name() -> impl ::std::fmt::Display { #name }
+        }
+    ))
+}
+
 fn generate_cdef_structure(str: &mut ItemStruct) -> Result<TokenStream> {
    syn_assert!(
        str.generics.params.is_empty(),
@@ -81,10 +101,9 @@ fn generate_cdef_structure(str: &mut ItemStruct) -> Result<TokenStream> {

    let ffi = ffi_crate();
    let ty = &str.ident;
-    let span = ty.span();
-    let build = generate_cdef_build(&get_cfields(&mut str.fields)?)?;
+    let build = generate_cdef_build(&parse_cfields(&mut str.fields)?)?;

-    Ok(quote_spanned!(span =>
+    Ok(quote!(
        unsafe impl #ffi::Cdef for #ty {
            fn build(b: &mut #ffi::CdefBuilder) { #build }
        }
@@ -100,18 +119,16 @@ fn generate_cdef_enum(enu: &mut ItemEnum) -> Result<TokenStream> {

    let ffi = ffi_crate();
    let ty = &enu.ident;
-    let span = ty.span();
    let build = enu
        .variants
        .iter_mut()
        .map(|variant| {
-            let span = variant.span();
-            let build = generate_cdef_build(&get_cfields(&mut variant.fields)?)?;
-            Ok(quote_spanned!(span => b.inner_struct(|b| { #build })))
+            let build = generate_cdef_build(&parse_cfields(&mut variant.fields)?)?;
+            Ok(quote!(b.inner_struct(|b| { #build })))
        })
        .collect::<Result<Vec<_>>>()?;

-    Ok(quote_spanned!(span =>
+    Ok(quote!(
        unsafe impl #ffi::Cdef for #ty {
            fn build(b: &mut #ffi::CdefBuilder) {
                b.field::<::std::ffi::c_int>("__tag").inner_union(|b| { #(#build;)* });
@@ -131,7 +148,7 @@ struct CFieldAttrs {
    opaque: bool,
 }

-fn get_cfields(fields: &mut Fields) -> Result<Vec<CField>> {
+fn parse_cfields(fields: &mut Fields) -> Result<Vec<CField>> {
    match fields {
        Fields::Named(fields) => fields.named.iter_mut(),
        Fields::Unnamed(fields) => fields.unnamed.iter_mut(),
@@ -155,13 +172,12 @@ fn parse_cfield_attrs(attrs: &mut Vec<Attribute>) -> Result<CFieldAttrs> {
    let mut parsed = CFieldAttrs::default();
    let mut i = 0;
    while let Some(attr) = attrs.get(i) {
-        if let Some(name) = attr.path().get_ident() {
-            if name == "opaque" {
+        let path = attr.path();
+        if path.is_ident("opaque") {
            parsed.opaque = true;
            attrs.remove(i);
            continue;
        }
-        }
        i += 1;
    }

@@ -185,7 +201,7 @@ fn generate_cdef_build(fields: &[CField]) -> Result<TokenStream> {
    for (i, field) in fields.iter().enumerate() {
        let ty = &field.ty;
        let offset = offset(i);
-        body.push(quote_spanned!(ty.span() =>
+        body.push(quote!(
            // round up current offset to the alignment of field type for field offset
            offset = (offset + #align_of::<#ty>() - 1) & !(#align_of::<#ty>() - 1);
            align = #max(align, #align_of::<#ty>());
--- a/crates/luaffi_impl/src/lib.rs
+++ b/crates/luaffi_impl/src/lib.rs
@@ -1,7 +1,6 @@
 use darling::{FromMeta, ast::NestedMeta};
 use proc_macro::TokenStream as TokenStream1;
 use quote::ToTokens;
-use syn::parse_macro_input;

 mod cdef;
 mod metatype;
@@ -17,8 +16,10 @@ pub fn cdef(args: TokenStream1, input: TokenStream1) -> TokenStream1 {
 }

 #[proc_macro_attribute]
-pub fn metatype(_args: TokenStream1, input: TokenStream1) -> TokenStream1 {
-    metatype::transform(parse_macro_input!(input))
+pub fn metatype(args: TokenStream1, input: TokenStream1) -> TokenStream1 {
+    NestedMeta::parse_meta_list(args.into())
+        .and_then(|meta| metatype::Args::from_list(&meta).map_err(Into::into))
+        .and_then(|args| metatype::transform(args, syn::parse(input)?))
        .unwrap_or_else(|err| err.into_compile_error().into_token_stream())
        .into()
 }
--- a/crates/luaffi_impl/src/metatype.rs
+++ b/crates/luaffi_impl/src/metatype.rs
@@ -1,23 +1,27 @@
 use crate::utils::{
-    StringLike, ffi_crate, is_optionlike, is_primitivelike, is_stringlike, is_unit, pat_ident,
-    syn_assert, syn_error, ty_name,
+    StringLike, ffi_crate, is_optionlike, is_primitivelike, is_resultlike, is_stringlike, is_unit,
+    pat_ident, syn_assert, syn_error, ty_name,
 };
+use darling::FromMeta;
 use proc_macro2::TokenStream;
 use quote::{ToTokens, format_ident, quote, quote_spanned};
 use std::{collections::HashSet, fmt, iter};
 use syn::{ext::IdentExt, spanned::Spanned, *};

-pub fn transform(mut imp: ItemImpl) -> Result<TokenStream> {
+#[derive(Debug, FromMeta)]
+pub struct Args {}
+
+pub fn transform(args: Args, mut imp: ItemImpl) -> Result<TokenStream> {
    syn_assert!(
        imp.generics.params.is_empty(),
        imp.generics,
        "cannot be generic (not yet implemented)"
    );

-    let impls = generate_impls(&mut imp)?;
+    let impls = generate_impls(&args, &mut imp)?;
    let mod_name = format_ident!("__{}_metatype", ty_name(&imp.self_ty)?);

-    Ok(quote_spanned!(imp.self_ty.span() =>
+    Ok(quote!(
        #imp

        #[doc(hidden)]
@@ -46,7 +50,7 @@ impl Registry {
    }
 }

-fn generate_impls(imp: &mut ItemImpl) -> Result<TokenStream> {
+fn generate_impls(_args: &Args, imp: &mut ItemImpl) -> Result<TokenStream> {
    let ffi = ffi_crate();
    let ty = imp.self_ty.clone();
    let ty_name = ty_name(&ty)?;
@@ -54,7 +58,27 @@ fn generate_impls(imp: &mut ItemImpl) -> Result<TokenStream> {
    let mut mms = HashSet::new();
    let mut lua_drop = None;

-    for func in get_ffi_functions(imp)? {
+    // process lua includes
+    imp.attrs.retain(|attr| {
+        if attr.path().is_ident("include") {
+            if let Ok(path) = attr.parse_args::<LitStr>() {
+                registry.build.push(quote_spanned!(path.span() =>
+                    b.include_lua(::std::include_str!(#path));
+                ));
+                return false;
+            } else if let Ok(chunk) = attr.parse_args::<Block>() {
+                registry.build.push(quote_spanned!(chunk.span() =>
+                    b.include_lua(#ffi::__internal::luaify_chunk!(#chunk));
+                ));
+                return false;
+            }
+        }
+
+        true
+    });
+
+    // process extern "Lua-C" ffi functions
+    for func in parse_ffi_functions(imp)? {
        if let Some(mm) = func.attrs.metamethod {
            syn_assert!(
                mms.insert(mm),
@@ -63,10 +87,11 @@ fn generate_impls(imp: &mut ItemImpl) -> Result<TokenStream> {
            );
        }

-        add_ffi_function(&mut registry, &func)?;
+        generate_ffi_function(&mut registry, &func)?;
    }

-    for func in get_lua_functions(imp)? {
+    // process extern "Lua" lua functions
+    for func in parse_lua_functions(imp)? {
        if let Some(mm) = func.attrs.metamethod {
            syn_assert!(
                mms.insert(mm),
@@ -75,24 +100,26 @@ fn generate_impls(imp: &mut ItemImpl) -> Result<TokenStream> {
            );
        }

-        if let Some(Metamethod::Gc) = func.attrs.metamethod {
+        if func.attrs.metamethod == Some(Metamethod::Gc) {
            lua_drop = Some(func);
        } else {
-            add_lua_function(&mut registry, &func)?;
+            generate_lua_function(&mut registry, &func)?;
        }
    }

+    // if no #[new] metamethod is defined, inject fallback new
    if !mms.contains(&Metamethod::New) {
        inject_fallback_new(&mut registry)?;
    }

+    // inject __gc/drop
    inject_merged_drop(&mut registry, lua_drop.as_ref())?;

    let shims = &registry.shims;
    let build = &registry.build;
    let exports = generate_ffi_exports(&registry)?;

-    Ok(quote_spanned!(ty.span() =>
+    Ok(quote!(
        impl #ty { #(#shims)* }

        unsafe impl #ffi::Metatype for #ty {
@@ -128,6 +155,25 @@ enum Metamethod {
    Ipairs,
 }

+impl Metamethod {
+    fn narg(&self) -> Option<usize> {
+        Some(match *self {
+            Self::Eq
+            | Self::Lt
+            | Self::Le
+            | Self::Concat
+            | Self::Add
+            | Self::Sub
+            | Self::Mul
+            | Self::Div
+            | Self::Mod
+            | Self::Pow => 2,
+            Self::Gc | Self::Len | Self::Unm | Self::ToString | Self::Pairs | Self::Ipairs => 1,
+            Self::Call | Self::New => return None,
+        })
+    }
+}
+
 impl TryFrom<&Ident> for Metamethod {
    type Error = Error;

@@ -192,10 +238,10 @@ impl ToTokens for Metamethod {

 struct FfiFunction {
    name: Ident,
-    is_async: bool,
-    params: Vec<PatType>,
+    params: Vec<(Ident, Type)>,
    ret: Type,
    attrs: FfiFunctionAttrs,
+    is_async: bool,
 }

 #[derive(Default)]
@@ -203,8 +249,8 @@ struct FfiFunctionAttrs {
    metamethod: Option<Metamethod>,
 }

-fn get_ffi_functions(imp: &mut ItemImpl) -> Result<Vec<FfiFunction>> {
-    let mut funcs = vec![];
+fn parse_ffi_functions(imp: &mut ItemImpl) -> Result<Vec<FfiFunction>> {
+    let mut parsed = vec![];

    for item in imp.items.iter_mut() {
        if let ImplItem::Fn(func) = item
@@ -224,30 +270,31 @@ fn get_ffi_functions(imp: &mut ItemImpl) -> Result<Vec<FfiFunction>> {
                .sig
                .inputs
                .iter()
-                .map(|arg| match arg {
+                .map(|arg| {
+                    Ok(match arg {
                        FnArg::Receiver(recv) => {
-                        let ty = &recv.ty;
-                        parse_quote_spanned!(ty.span() => self: #ty)
+                            (Ident::new("self", recv.span()), (*recv.ty).clone())
                        }
-                    FnArg::Typed(ty) => ty.clone(),
+                        FnArg::Typed(ty) => (pat_ident(&ty.pat)?.clone(), (*ty.ty).clone()),
                    })
-                .collect();
+                })
+                .collect::<Result<_>>()?;

            let ret = match func.sig.output {
                ReturnType::Default => parse_quote!(()),
                ReturnType::Type(_, ref ty) => (**ty).clone(),
            };

-            for param in params.iter() {
-                // double underscores are reserved for generated glue code
+            for (name, ty) in params.iter() {
+                // double underscores are reserved for glue code
                syn_assert!(
-                    !pat_ident(&param.pat)?.to_string().starts_with("__"),
-                    param.pat,
+                    !name.to_string().starts_with("__"),
+                    name,
                    "parameter names should not start with `__`"
                );

-                // lifetime should be determined by the caller (lua)
-                if let Type::Reference(ref ty) = *param.ty {
+                // lifetime should be determined by the caller (which is lua)
+                if let Type::Reference(ty) = ty {
                    syn_assert!(
                        ty.lifetime.is_none(),
                        ty.lifetime,
@@ -257,21 +304,30 @@ fn get_ffi_functions(imp: &mut ItemImpl) -> Result<Vec<FfiFunction>> {
            }

            let attrs = parse_ffi_function_attrs(&mut func.attrs)?;
-            attrs.metamethod.map(|mm| document_metamethod(func, mm));

-            document_ffi_function(func);
+            if let Some(mm) = attrs.metamethod
+                && let Some(narg) = mm.narg()
+            {
+                syn_assert!(
+                    params.len() == narg,
+                    func.sig.inputs,
+                    "expected {narg} parameters for `{mm}` metamethod"
+                );
+            }

-            funcs.push(FfiFunction {
+            parsed.push(FfiFunction {
                name: func.sig.ident.clone(),
-                is_async: func.sig.asyncness.is_some(),
                params,
                ret,
                attrs,
+                is_async: func.sig.asyncness.is_some(),
            });
+
+            document_ffi_function(func, parsed.last().unwrap());
        }
    }

-    Ok(funcs)
+    Ok(parsed)
 }

 fn parse_ffi_function_attrs(attrs: &mut Vec<Attribute>) -> Result<FfiFunctionAttrs> {
@@ -279,14 +335,10 @@ fn parse_ffi_function_attrs(attrs: &mut Vec<Attribute>) -> Result<FfiFunctionAtt
    let mut i = 0;
    while let Some(attr) = attrs.get(i) {
        if let Some(name) = attr.path().get_ident()
-            && let Ok(method) = Metamethod::try_from(name)
+            && let Ok(mm) = Metamethod::try_from(&name.unraw())
        {
-            match method {
-                Metamethod::Gc => syn_error!(attr, "implement `Drop` instead"),
-                _ => {}
-            }
-
-            parsed.metamethod = Some(method);
+            syn_assert!(mm != Metamethod::Gc, attr, "implement `Drop` instead");
+            parsed.metamethod = Some(mm);
            attrs.remove(i);
        } else {
            i += 1;
@@ -345,7 +397,7 @@ fn get_ffi_ret_type(ty: &Type) -> FfiReturnType {
    }
 }

-fn add_ffi_function(registry: &mut Registry, func: &FfiFunction) -> Result<()> {
+fn generate_ffi_function(registry: &mut Registry, func: &FfiFunction) -> Result<()> {
    let ffi = ffi_crate();
    let ty = &registry.ty;
    let func_name = &func.name;
@@ -360,144 +412,153 @@ fn add_ffi_function(registry: &mut Registry, func: &FfiFunction) -> Result<()> {
    let func_params = &func.params; // target function parameters
    let func_ret = &func.ret; // target function return type
    let mut func_args = vec![]; // target function arguments
-
    let mut shim_params = vec![]; // shim function parameters
-    let mut shim_ret = if func.is_async {
-        // shim function return type
-        quote_spanned!(func_ret.span() => #ffi::future::lua_future<impl ::std::future::Future<Output = #func_ret>>)
-    } else {
-        quote_spanned!(func_ret.span() => <#func_ret as #ffi::IntoFfi>::Into)
-    };
-
-    let mut asserts = vec![]; // compile-time builder asserts
+    let mut asserts = vec![]; // compile-time asserts
    let mut build = vec![]; // ffi builder body

-    // for __new metamethods, ignore the first argument (ctype of self, for which there is no
-    // equivalent in C)
-    if func.attrs.metamethod == Some(Metamethod::New) {
+    match func.attrs.metamethod {
+        Some(Metamethod::New) => {
+            // for __new metamethods, ignore the first argument (ctype of self, for which there is
+            // no equivalent in C)
            build.push(quote!(
                b.param_ignored();
            ));
        }
+        Some(Metamethod::Eq) => {
+            // for __eq metamethods, set special eq mode to return false on argument type mismatch
+            // instead of throwing
+            build.push(quote!(
+                b.set_eqmm(true);
+            ));
+        }
+        _ => {}
+    }

-    for (i, param) in func_params.iter().enumerate() {
-        let func_param = &param.ty;
+    for (i, (name, func_param)) in func_params.iter().enumerate() {
+        let span = func_param.span();
+        let name = name.unraw().to_string();
        let shim_param = format_ident!("arg{i}");
-        let name = pat_ident(&param.pat)?.unraw().to_string();

        match get_ffi_param_type(func_param) {
            FfiParameterType::Default => {
-                shim_params.push(quote_spanned!(func_param.span() =>
+                shim_params.push(quote_spanned!(span =>
                    #shim_param: <#func_param as #ffi::FromFfi>::From
                ));
-                func_args.push(quote_spanned!(param.pat.span() =>
+                func_args.push(quote_spanned!(span =>
                    <#func_param as #ffi::FromFfi>::convert(#shim_param)
                ));
-                build.push(quote_spanned!(param.pat.span() =>
+                build.push(if func.attrs.metamethod == Some(Metamethod::Eq) {
+                    quote_spanned!(span =>
+                        // preliminary `return false` for type mismatch in __eq mode. we just check
+                        // against the ctype of Self because that's what __eq should be comparing
+                        // anyway.
+                        b.param_ctchecked::<#func_param, Self>(#name);
+                    )
+                } else {
+                    quote_spanned!(span =>
                        b.param::<#func_param>(#name);
-                ));
+                    )
+                });
            }
            ty @ (FfiParameterType::StringLike(str) | FfiParameterType::OptionStringLike(str)) => {
                let shim_param_len = format_ident!("arg{i}_len");
-                shim_params.push(quote_spanned!(func_param.span() =>
+                shim_params.push(quote_spanned!(span =>
                    #shim_param: ::std::option::Option<&::std::primitive::u8>,
                    #shim_param_len: ::std::primitive::usize
                ));
                let allow_nil = matches!(ty, FfiParameterType::OptionStringLike(_));
                let check_utf8 = matches!(str, StringLike::Str);
-                let mut func_arg = quote_spanned!(func_param.span() =>
+                let mut func_arg = quote_spanned!(span =>
                    #shim_param.map(|s| ::std::slice::from_raw_parts(s, #shim_param_len))
                );
                func_arg = match str {
                    StringLike::SliceU8 => func_arg,
                    StringLike::BStr => {
-                        quote_spanned!(func_param.span() => #func_arg.map(::bstr::BStr::new))
+                        quote_spanned!(span => #func_arg.map(::bstr::BStr::new))
                    }
                    StringLike::Str => {
-                        quote_spanned!(func_param.span() => #func_arg.map(|s| {
+                        quote_spanned!(span => #func_arg.map(|s| {
                            ::std::debug_assert!(::std::str::from_utf8(s).is_ok());
                            ::std::str::from_utf8_unchecked(s)
                        }))
                    }
                };
                if !allow_nil {
-                    func_arg = quote_spanned!(func_param.span() => {
+                    func_arg = quote_spanned!(span => {
                        let arg = #func_arg;
                        ::std::debug_assert!(arg.is_some());
                        arg.unwrap_unchecked()
                    });
                }
                func_args.push(func_arg);
-                build.push(quote_spanned!(param.pat.span() =>
+                build.push(quote_spanned!(span =>
                    b.param_str(#name, #allow_nil, #check_utf8);
                ));
            }
        }
    }

-    // shim function body
-    let mut shim_body = if func.is_async {
-        // for async functions, wrapped the returned future in lua_future
-        quote_spanned!(func_name.span() => #ffi::future::lua_future::new(Self::#func_name(#(#func_args),*)))
-    } else {
-        quote_spanned!(func_name.span() => <#func_ret as #ffi::IntoFfi>::convert(Self::#func_name(#(#func_args),*)))
-    };
+    let func_call = quote!(Self::#func_name(#(#func_args),*)); // target function call

-    if !func.is_async {
+    // shim function body and return type
+    let (shim_body, shim_ret) = if func.is_async {
+        let span = func_ret.span();
+        (
+            // for async functions, wrapped the returned future in lua_future
+            quote_spanned!(span => #ffi::future::lua_future::new(#func_call)),
+            quote_spanned!(span => #ffi::future::lua_future<impl ::std::future::Future<Output = #func_ret>>),
+        )
+    } else {
+        let span = func_ret.span();
        match get_ffi_ret_type(&func_ret) {
            FfiReturnType::Void => {
-                asserts.push(quote_spanned!(func_ret.span() =>
+                asserts.push(quote_spanned!(span =>
                    <<#func_ret as #ffi::IntoFfi>::Into as #ffi::Type>::ty() == #ffi::TypeType::Void
                ));
+                (func_call, quote_spanned!(span => ()))
            }
            FfiReturnType::ByValue => {
-                asserts.push(quote_spanned!(func_ret.span() =>
+                asserts.push(quote_spanned!(span =>
                    <#func_ret as #ffi::IntoFfi>::convention() == #ffi::FfiReturnConvention::ByValue
                ));
+                (
+                    quote_spanned!(span => <#func_ret as #ffi::IntoFfi>::convert(#func_call)),
+                    quote_spanned!(span => <#func_ret as #ffi::IntoFfi>::Into),
+                )
            }
            FfiReturnType::ByOutParam => {
-                asserts.push(quote_spanned!(func_ret.span() =>
+                asserts.push(quote_spanned!(span =>
                    <#func_ret as #ffi::IntoFfi>::convention() == #ffi::FfiReturnConvention::ByOutParam
                ));
-
-                shim_params.insert(0, quote_spanned!(func_ret.span() => out: *mut #shim_ret));
-
-                (shim_body, shim_ret) = (
-                    quote_spanned!(func_ret.span() => ::std::ptr::write(out, #shim_body)),
-                    quote_spanned!(func_ret.span() => ()),
-                );
+                let out = quote_spanned!(span => out: *mut <#func_ret as #ffi::IntoFfi>::Into);
+                shim_params.insert(0, out);
+                (
+                    quote_spanned!(span => ::std::ptr::write(out, <#func_ret as #ffi::IntoFfi>::convert(#func_call))),
+                    quote_spanned!(span => ()),
+                )
+            }
        }
    };
-    }

-    // build.push(quote_spanned!(func_name.span() =>
-    //     b.call_inferred(#c_name, Self::#func_name);
-    // ));
-
-    build.push({
+    build.push(if func.is_async {
+        // we can't name the future from an async function, so instead we provide a closure with a
+        // "dummy call" that never gets called so that the builder can infer the return type from
+        // the closure
        let infer_args = iter::repeat_n(quote!(::std::unreachable!()), func_params.len());
-        let infer = if func.is_async {
-            quote!(|| #ffi::future::lua_future::new(Self::#func_name(#(#infer_args),*)))
+        quote!(b.call_inferred(#c_name, || {
+            #ffi::future::lua_future::new(Self::#func_name(#(#infer_args),*))
+        });)
    } else {
-            quote!(|| Self::#func_name(#(#infer_args),*))
-        };
-        quote_spanned!(func_name.span() => b.call_inferred(#c_name, #infer);)
+        quote!(b.call::<#func_ret>(#c_name);)
    });

-    registry.build.push(quote_spanned!(func_name.span() =>
-        #(::std::assert!(#asserts);)*
-    ));
-
+    registry.build.push(quote!(#(::std::assert!(#asserts);)*));
    registry.build.push(match func.attrs.metamethod {
-        Some(ref mm) => quote_spanned!(func_name.span() =>
-            b.metatable(#mm, |b| { #(#build)* });
-        ),
-        None => quote_spanned!(func_name.span() =>
-            b.index(#lua_name, |b| { #(#build)* });
-        ),
+        Some(mm) => quote!(b.metatable(#mm, |b| { #(#build)* });),
+        None => quote!(b.index(#lua_name, |b| { #(#build)* });),
    });

-    registry.shims.push(parse_quote_spanned!(func_name.span() =>
+    registry.shims.push(parse_quote!(
        #[unsafe(export_name = #c_name)]
        unsafe extern "C" fn #shim_name(#(#shim_params),*) -> #shim_ret { unsafe { #shim_body } }
    ));
@@ -509,7 +570,7 @@ fn generate_ffi_exports(registry: &Registry) -> Result<TokenStream> {
    let ty = &registry.ty;
    let names = registry.shims.iter().map(|f| &f.sig.ident);

-    Ok(quote_spanned!(ty.span() =>
+    Ok(quote!(
        // this ensures ffi function symbol exports are actually present in the resulting binary,
        // otherwise they may get dead code-eliminated before it reaches the linker
        #[used]
@@ -531,8 +592,8 @@ struct LuaFunctionAttrs {
    metamethod: Option<Metamethod>,
 }

-fn get_lua_functions(imp: &mut ItemImpl) -> Result<Vec<LuaFunction>> {
-    let mut funcs = vec![];
+fn parse_lua_functions(imp: &mut ItemImpl) -> Result<Vec<LuaFunction>> {
+    let mut parsed = vec![];

    for item in imp.items.iter_mut() {
        if let ImplItem::Fn(func) = item
@@ -546,41 +607,70 @@ fn get_lua_functions(imp: &mut ItemImpl) -> Result<Vec<LuaFunction>> {
                "cannot be generic"
            );

+            syn_assert!(
+                func.sig.constness.is_none(),
+                func.sig.constness,
+                "cannot be const"
+            );
+
            let mut params: Vec<_> = func
                .sig
                .inputs
                .iter()
-                .map(|arg| {
-                    Ok(match arg {
-                        FnArg::Receiver(recv) => Pat::Type(parse_quote_spanned!(recv.span() =>
-                            self: cdata
-                        )),
-                        FnArg::Typed(ty) => Pat::Type(ty.clone()),
+                .map(|arg| match arg {
+                    FnArg::Receiver(recv) => parse_quote_spanned!(recv.span() => self),
+                    FnArg::Typed(ty) => (*ty.pat).clone(), // ignore parameter type (only used for documentation purposes)
                })
-                })
-                .collect::<Result<_>>()?;
+                .collect();

            if let Some(ref variadic) = func.sig.variadic {
+                // need to transform variadic to the `varidic!()` luaify builtin macro because we
+                // luaify a closure below, and closures don't have variadics.
                params.push(parse_quote_spanned!(variadic.span() => variadic!()));
            }

            let attrs = parse_lua_function_attrs(&mut func.attrs)?;
-            attrs.metamethod.map(|mm| document_metamethod(func, mm));

-            document_lua_function(func);
+            if let Some(mm) = attrs.metamethod
+                && let Some(narg) = mm.narg()
+            {
+                syn_assert!(
+                    params.len() == narg,
+                    func.sig.inputs,
+                    "expected {narg} parameters for `{mm}` metamethod"
+                );
+            }

-            funcs.push(LuaFunction {
+            parsed.push(LuaFunction {
                name: func.sig.ident.clone(),
                params,
                body: func.block.clone(),
                attrs,
            });

+            document_lua_function(func, parsed.last().unwrap());
            stub_lua_function(func)?;
        }
    }

-    Ok(funcs)
+    Ok(parsed)
+}
+
+fn parse_lua_function_attrs(attrs: &mut Vec<Attribute>) -> Result<LuaFunctionAttrs> {
+    let mut parsed = LuaFunctionAttrs::default();
+    let mut i = 0;
+    while let Some(attr) = attrs.get(i) {
+        if let Some(name) = attr.path().get_ident()
+            && let Ok(mm) = Metamethod::try_from(&name.unraw())
+        {
+            parsed.metamethod = Some(mm);
+            attrs.remove(i);
+        } else {
+            i += 1;
+        }
+    }
+
+    Ok(parsed)
 }

 fn stub_lua_function(func: &mut ImplItemFn) -> Result<()> {
@@ -592,84 +682,46 @@ fn stub_lua_function(func: &mut ImplItemFn) -> Result<()> {
    func.attrs.push(parse_quote!(#[allow(unused)]));
    func.block.stmts.clear();
    func.block.stmts.push(parse_quote!(
-        ::std::unreachable!("cannot call lua function from rust");
+        const fn has_annotation<T: #ffi::Annotation>() {}
    ));

-    let inputs = &mut func.sig.inputs;
-    let output = &mut func.sig.output;
-
-    for input in inputs.iter_mut() {
-        if let FnArg::Typed(pat) = input
-            && let Ok(stub) = stub_lua_type(&pat.ty)
-        {
-            pat.ty = stub.into();
-        }
-    }
-
-    if let ReturnType::Type(_, ty) = output
-        && let Ok(stub) = stub_lua_type(ty)
-    {
-        *ty = stub.into();
-    }
-
+    // convert `...` variadic to a `rest: luaffi::marker::Many` parameter
    if let Some(ref variadic) = func.sig.variadic {
-        let ty = quote_spanned!(variadic.span() => variadic);
-        inputs.push(parse_quote!(rest: #ffi::__internal::stub_types::#ty));
+        let param = Ident::new("rest", variadic.span());
+        let ty = quote_spanned!(variadic.span() => many);
        func.sig.variadic = None;
+        func.sig
+            .inputs
+            .push(parse_quote!(#param: #ffi::marker::#ty));
    }

+    for param in func.sig.inputs.iter() {
+        let ty = match param {
+            FnArg::Receiver(recv) => &recv.ty,
+            FnArg::Typed(ty) => &ty.ty,
+        };
+
+        // temporary assertion until we implement annotation generation
+        func.block.stmts.push(parse_quote!(
+            has_annotation::<#ty>();
+        ));
+    }
+
+    // temporary assertion until we implement annotation generation
+    if let ReturnType::Type(_, ref ty) = func.sig.output {
+        func.block.stmts.push(parse_quote!(
+            has_annotation::<#ty>();
+        ));
+    }
+
+    func.block.stmts.push(parse_quote!(
+        ::std::unreachable!(r#"cannot call extern "Lua" function from rust"#);
+    ));
+
    Ok(())
 }

-fn stub_lua_type(ty: &Type) -> Result<Type> {
-    let ffi = ffi_crate();
-    let span = ty.span();
-    let ty = if let Type::Infer(_) = ty {
-        quote_spanned!(span => any)
-    } else {
-        match ty_name(ty)?.to_string().as_str() {
-            "any" => quote_spanned!(span => any),
-            "nil" => quote_spanned!(span => nil),
-            "boolean" => quote_spanned!(span => boolean),
-            "lightuserdata" => quote_spanned!(span => lightuserdata),
-            "number" => quote_spanned!(span => number),
-            "integer" => quote_spanned!(span => integer),
-            "string" => quote_spanned!(span => string),
-            "table" => quote_spanned!(span => table),
-            "function" => quote_spanned!(span => function),
-            "userdata" => quote_spanned!(span => userdata),
-            "thread" => quote_spanned!(span => thread),
-            "cdata" => quote_spanned!(span => cdata),
-            _ => syn_error!(ty, "unknown lua type"),
-        }
-    };
-
-    Ok(parse_quote!(#ffi::__internal::stub_types::#ty))
-}
-
-fn parse_lua_function_attrs(attrs: &mut Vec<Attribute>) -> Result<LuaFunctionAttrs> {
-    let mut parsed = LuaFunctionAttrs::default();
-    let mut i = 0;
-    while let Some(attr) = attrs.get(i) {
-        if let Some(name) = attr.path().get_ident()
-            && let Ok(method) = Metamethod::try_from(name)
-        {
-            match method {
-                Metamethod::New => syn_error!(attr, r#"cannot be applied to a lua function"#),
-                _ => {}
-            }
-
-            parsed.metamethod = Some(method);
-            attrs.remove(i);
-        } else {
-            i += 1;
-        }
-    }
-
-    Ok(parsed)
-}
-
-fn add_lua_function(registry: &mut Registry, func: &LuaFunction) -> Result<()> {
+fn generate_lua_function(registry: &mut Registry, func: &LuaFunction) -> Result<()> {
    let ffi = ffi_crate();
    let luaify = quote!(#ffi::__internal::luaify!);
    let func_name = &func.name;
@@ -678,12 +730,8 @@ fn add_lua_function(registry: &mut Registry, func: &LuaFunction) -> Result<()> {
    let name = func_name.unraw().to_string();

    registry.build.push(match func.attrs.metamethod {
-        Some(ref mm) => quote_spanned!(func_name.span() =>
-            b.metatable_raw(#mm, #luaify(|#(#params),*| #body));
-        ),
-        None => quote_spanned!(func_name.span() =>
-            b.index_raw(#name, #luaify(|#(#params),*| #body));
-        ),
+        Some(mm) => quote!(b.metatable_raw(#mm, #luaify(|#(#params),*| #body));),
+        None => quote!(b.index_raw(#name, #luaify(|#(#params),*| #body));),
    });

    Ok(())
@@ -708,50 +756,40 @@ fn inject_merged_drop(registry: &mut Registry, lua: Option<&LuaFunction>) -> Res
    let luaify = quote!(#ffi::__internal::luaify!);
    let ty = &registry.ty;
    let shim_name = format_ident!("__ffi_drop");
-    let c_name = format_ident!("{}_drop", ty.unraw());
+    let c_name = format_ident!("__{}_drop", ty.unraw());
    let c_name_str = c_name.to_string();

    if let Some(lua) = lua {
-        syn_assert!(
-            lua.params.len() == 1,
-            lua.name,
-            "finaliser must take exactly one parameter"
-        );
-
-        syn_assert!(
-            pat_ident(&lua.params[0])? == "self",
-            lua.params[0],
-            "finaliser parameter must be `self`"
-        );
-
-        let params = &lua.params;
+        let param = pat_ident(&lua.params[0])?;
        let body = &lua.body;

-        registry.build.push(quote_spanned!(ty.span() =>
+        syn_assert!(param == "self", param, "finaliser parameter must be `self`");
+
+        registry.build.push(quote!(
            if ::std::mem::needs_drop::<Self>() {
                // if we have both a lua-side finaliser and a rust drop, then merge the finalisers
                // by doing the lua part first then drop rust
-                b.declare::<#ffi::UnsafeExternCFn<(*mut Self,), ()>>(#c_name_str);
+                b.declare::<#ffi::ExternCFn<(*mut Self,), ()>>(#c_name_str);
                b.metatable_raw("gc", #luaify(|self| {
                    raw!(#luaify(#body)); // embed the lua part inside a do block
                    __C::#c_name(self);
                }));
            } else {
                // we only have a lua-side finaliser
-                b.metatable_raw("gc", #luaify(|#(#params),*| #body));
+                b.metatable_raw("gc", #luaify(|self| #body));
            }
        ));
    } else {
-        registry.build.push(quote_spanned!(ty.span() =>
+        registry.build.push(quote!(
            if ::std::mem::needs_drop::<Self>() {
                // we only have a rust drop
-                b.declare::<#ffi::UnsafeExternCFn<(*mut Self,), ()>>(#c_name_str);
+                b.declare::<#ffi::ExternCFn<(*mut Self,), ()>>(#c_name_str);
                b.metatable_raw("gc", ::std::format_args!("__C.{}", #c_name_str));
            }
        ));
    }

-    registry.shims.push(parse_quote_spanned!(ty.span() =>
+    registry.shims.push(parse_quote!(
        #[unsafe(export_name = #c_name_str)]
        unsafe extern "C" fn #shim_name(ptr: *mut Self) {
            unsafe { ::std::ptr::drop_in_place(ptr) }
@@ -761,44 +799,176 @@ fn inject_merged_drop(registry: &mut Registry, lua: Option<&LuaFunction>) -> Res
    Ok(())
 }

-fn document_ffi_function(func: &mut ImplItemFn) {
-    func.attrs.insert(0, parse_quote!(#[doc =
-        r#"<span class="stab" title="This is a C/FFI function." style="float: right; font-weight: 500; margin-left: 3px; padding-left: 5px; padding-right: 5px;">FFI</span>"#
-    ]));
+// the transparency makes it work in dark mode too
+// const FFI_COLOR: &str = "rgba(255, 222, 118, 0.3)"; // yellow
+// const LUA_COLOR: &str = "rgba(188, 222, 255, 0.3)"; // blue
+const FALLIBLE_COLOR: &str = "rgba(255, 168, 168, 0.3)"; // red
+const ASYNC_COLOR: &str = "rgba(188, 222, 255, 0.3)"; // blue
+const METAMETHOD_COLOR: &str = "rgba(255, 222, 118, 0.3)"; // yellow
+
+struct StabConfig {
+    text: &'static str,
+    desc: &'static str,
+    color: &'static str,
+    strong: bool,
 }

-fn document_lua_function(func: &mut ImplItemFn) {
-    func.attrs.insert(0, parse_quote!(#[doc =
-        r#"<span class="stab" title="This is a Lua function." style="float: right; font-weight: 500; margin-left: 3px; padding-left: 5px; padding-right: 5px;">Lua</span>"#
-    ]));
+fn generate_stab(
+    StabConfig {
+        text,
+        desc,
+        color,
+        strong,
+    }: StabConfig,
+) -> Attribute {
+    let attrs = vec![
+        ("class", "stab".into()),
+        ("title", desc.into()),
+        ("aria-label", desc.into()),
+        ("style", {
+            let mut style = vec![
+                ("float", "right"),
+                ("margin", "1px"),
+                ("margin-left", "4px"),
+                ("padding-left", "5px"),
+                ("padding-right", "5px"),
+                ("background", color),
+            ];
+
+            if strong {
+                style.push(("font-weight", "600"));
            }

-fn document_metamethod(func: &mut ImplItemFn, method: Metamethod) {
-    let s = match method {
-        Metamethod::Eq => "This is a metamethod which is called by the `==` operator.".into(),
-        Metamethod::Len => "This is a metamethod which is called by the `#` operator.".into(),
-        Metamethod::Lt => "This is a metamethod which is called by the `<` operator.".into(),
-        Metamethod::Le => "This is a metamethod which is called by the `<=` operator.".into(),
-        Metamethod::Concat => "This is a metamethod which is called by the `..` operator.".into(),
-        Metamethod::Add => "This is a metamethod which is called by the `+` operator.".into(),
-        Metamethod::Sub => "This is a metamethod which is called by the `-` operator.".into(),
-        Metamethod::Mul => "This is a metamethod which is called by the `*` operator.".into(),
-        Metamethod::Div => "This is a metamethod which is called by the `/` operator.".into(),
-        Metamethod::Mod => "This is a metamethod which is called by the `%` operator.".into(),
-        Metamethod::Pow => "This is a metamethod which is called by the `^` operator.".into(),
-        Metamethod::Unm => "This is a metamethod which is called by the `-` operator.".into(),
+            style
+                .into_iter()
+                .map(|(k, v)| format!("{k}: {v}"))
+                .collect::<Vec<_>>()
+                .join("; ")
+        }),
+    ];
+
+    let attrs = attrs
+        .into_iter()
+        .map(|(k, v)| format!(r#"{k}="{v}""#))
+        .collect::<Vec<_>>()
+        .join(" ");
+
+    let tag = format!(r#"<span {attrs}>{text}</span>"#);
+    parse_quote!(#[doc = #tag])
+}
+
+fn document_ffi_function(item: &mut ImplItemFn, func: &FfiFunction) {
+    let mut attrs = vec![];
+
+    // attrs.push(generate_stab(StabConfig {
+    //     text: "FFI",
+    //     desc: "This function is implemented in Rust and called via FFI.",
+    //     color: FFI_COLOR,
+    //     strong: true,
+    // }));
+
+    generate_stab_fallible(item).map(|stab| attrs.push(stab));
+    generate_stab_async(item).map(|stab| attrs.push(stab));
+    generate_stab_metamethod(func.attrs.metamethod).map(|(stab, help)| {
+        attrs.push(stab);
+        item.attrs.push(help);
+    });
+
+    item.attrs.splice(0..0, attrs);
+}
+
+fn document_lua_function(item: &mut ImplItemFn, func: &LuaFunction) {
+    let mut attrs = vec![];
+
+    // attrs.push(generate_stab(StabConfig {
+    //     text: "Lua",
+    //     desc: "This function is implemented in Lua.",
+    //     color: LUA_COLOR,
+    //     strong: true,
+    // }));
+
+    generate_stab_fallible(item).map(|stab| attrs.push(stab));
+    generate_stab_async(item).map(|stab| attrs.push(stab));
+    generate_stab_metamethod(func.attrs.metamethod).map(|(stab, help)| {
+        attrs.push(stab);
+        item.attrs.push(help);
+    });
+
+    item.attrs.splice(0..0, attrs);
+}
+
+fn generate_stab_async(item: &ImplItemFn) -> Option<Attribute> {
+    item.sig.asyncness.as_ref().map(|_| {
+        generate_stab(StabConfig {
+            text: "Async",
+            desc: "This function is asynchronous and will yield the calling thread.",
+            color: ASYNC_COLOR,
+            strong: false,
+        })
+    })
+}
+
+fn generate_stab_fallible(item: &ImplItemFn) -> Option<Attribute> {
+    match item.sig.output {
+        ReturnType::Default => None,
+        ReturnType::Type(_, ref ty) => is_resultlike(ty).map(|_| {
+            generate_stab(StabConfig {
+                text: "Fallible",
+                desc: "This function is fallible and may throw an error on failure.",
+                color: FALLIBLE_COLOR,
+                strong: false,
+            })
+        }),
+    }
+}
+
+fn generate_stab_metamethod(mm: Option<Metamethod>) -> Option<(Attribute, Attribute)> {
+    mm.map(|mm| {
+        let stab = generate_stab(StabConfig {
+            text: "Metamethod",
+            desc: "This function is a metamethod.",
+            color: METAMETHOD_COLOR,
+            strong: false,
+        });
+
+        let help = match mm {
+            Metamethod::Eq => "This function is a metamethod which is called by the `==` operator.",
+            Metamethod::Len => "This function is a metamethod which is called by the `#` operator.",
+            Metamethod::Lt => "This function is a metamethod which is called by the `<` operator.",
+            Metamethod::Le => "This function is a metamethod which is called by the `<=` operator.",
+            Metamethod::Concat => {
+                "This function is a metamethod which is called by the `..` operator."
+            }
+            Metamethod::Call => {
+                "This function is a metamethod which can be called by calling \
+                `(...)` on the value directly."
+            }
+            Metamethod::Add => "This function is a metamethod which is called by the `+` operator.",
+            Metamethod::Sub => "This function is a metamethod which is called by the `-` operator.",
+            Metamethod::Mul => "This function is a metamethod which is called by the `*` operator.",
+            Metamethod::Div => "This function is a metamethod which is called by the `/` operator.",
+            Metamethod::Mod => "This function is a metamethod which is called by the `%` operator.",
+            Metamethod::Pow => "This function is a metamethod which is called by the `^` operator.",
+            Metamethod::Unm => "This function is a metamethod which is called by the `-` operator.",
            Metamethod::ToString => {
-            "This is a metamethod which can be called by the `tostring` built-in function.".into()
+                "This function is a metamethod which is called by the \
+                [`tostring(...)`](https://www.lua.org/manual/5.1/manual.html#pdf-tostring) \
+                built-in function."
            }
            Metamethod::Pairs => {
-            "This is a metamethod which can be called by the `pairs` built-in function.".into()
+                "This function is a metamethod which is called by the \
+                [`pairs(...)`](https://www.lua.org/manual/5.1/manual.html#pdf-pairs) \
+                built-in function."
            }
            Metamethod::Ipairs => {
-            "This is a metamethod which can be called by the `ipairs` built-in function.".into()
+                "This function is a metamethod which is called by the \
+                [`ipairs(...)`](https://www.lua.org/manual/5.1/manual.html#pdf-ipairs) \
+                built-in function."
            }
-        _ => format!("This is a metamethod and cannot be called directly."),
+            _ => "This function is a metamethod and cannot be called directly.",
        };

-    func.attrs.push(parse_quote!(#[doc = ""]));
-    func.attrs.push(parse_quote!(#[doc = #s]));
+        let help = format!("\n# Metamethod\n\n{help}");
+        (stab, parse_quote!(#[doc = #help]))
+    })
 }
--- a/crates/luaffi_impl/src/utils.rs
+++ b/crates/luaffi_impl/src/utils.rs
@@ -1,5 +1,5 @@
 use std::env;
-use syn::{spanned::Spanned, *};
+use syn::{ext::IdentExt, spanned::Spanned, *};

 macro_rules! syn_error {
    ($src:expr, $($fmt:expr),+) => {{
@@ -63,7 +63,7 @@ pub fn is_primitivelike(ty: &Type) -> bool {
        Type::Path(path) => {
            if let Some(name) = path.path.get_ident() {
                return matches!(
-                    name.to_string().as_str(),
+                    name.unraw().to_string().as_str(),
                    "bool"
                        | "u8"
                        | "u16"
@@ -115,32 +115,38 @@ pub fn is_stringlike(ty: &Type) -> Option<StringLike> {
        && ty.mutability.is_none()
        && ty.lifetime.is_none()
    {
-        match *ty.elem {
+        Some(match *ty.elem {
            Type::Slice(ref slice) => {
                // match &[u8]
                if let Type::Path(ref path) = *slice.elem
                    && let Some(name) = path.path.get_ident()
-                    && name == "u8"
                {
-                    return Some(StringLike::SliceU8);
+                    match name.unraw().to_string().as_str() {
+                        "u8" => StringLike::SliceU8,
+                        _ => return None,
+                    }
+                } else {
+                    return None;
                }
            }
            Type::Path(ref path) => {
                // match &str or &BStr
                if let Some(name) = path.path.get_ident() {
-                    match name.to_string().as_str() {
-                        "str" => return Some(StringLike::Str),
-                        "BStr" => return Some(StringLike::BStr),
-                        _ => {}
+                    match name.unraw().to_string().as_str() {
+                        "str" => StringLike::Str,
+                        "BStr" => StringLike::BStr,
+                        _ => return None,
+                    }
+                } else {
+                    return None;
                }
            }
-            }
-            _ => {}
-        }
-    }
-
+            _ => return None,
+        })
+    } else {
        None
    }
+}

 pub fn is_optionlike(ty: &Type) -> Option<&Type> {
    if let Type::Path(path) = ty
@@ -157,3 +163,19 @@ pub fn is_optionlike(ty: &Type) -> Option<&Type> {
        None
    }
 }
+
+pub fn is_resultlike(ty: &Type) -> Option<&Type> {
+    if let Type::Path(path) = ty
+        && path.path.leading_colon.is_none()
+        && path.path.segments.len() == 1
+        && let Some(segment) = path.path.segments.get(0)
+        && segment.ident == "Result"
+        && let PathArguments::AngleBracketed(ref angle) = segment.arguments
+        && angle.args.len() <= 2 // allow Result<T, E> or Result<T>
+        && let Some(GenericArgument::Type(ty)) = angle.args.get(0)
+    {
+        Some(ty)
+    } else {
+        None
+    }
+}
--- a/crates/luaify/Cargo.toml
+++ b/crates/luaify/Cargo.toml
@@ -14,3 +14,6 @@ proc-macro = true
 proc-macro2 = "1.0.95"
 quote = "1.0.40"
 syn = { version = "2.0.103", features = ["full", "visit-mut"] }
+
+[dev-dependencies]
+pretty_assertions = "1.4.1"
--- a/crates/luaify/src/generate.rs
+++ b/crates/luaify/src/generate.rs
@@ -14,6 +14,12 @@ pub fn generate(expr: &Expr) -> Result<TokenStream> {
    Ok(f.done())
 }

+pub fn generate_chunk(block: &Block) -> Result<TokenStream> {
+    let mut f = Formatter::default();
+    generate_block(&mut f, &block, Context::stmt(false))?;
+    Ok(f.done())
+}
+
 #[derive(Default)]
 struct Formatter {
    buf: String,
@@ -910,7 +916,7 @@ fn generate_pat_typed(f: &mut Formatter, typed: &PatType, cx: PatContext) -> Res
    assert_no_attrs!(typed);
    match *typed.ty {
        Type::Infer(_) => generate_pat(f, &typed.pat, cx),
-        ref ty => syn_error!(ty, "cannot have type"),
+        ref ty => syn_error!(ty, "cannot specify type"),
    }
 }

--- a/crates/luaify/src/lib.rs
+++ b/crates/luaify/src/lib.rs
@@ -1,4 +1,10 @@
-use crate::{generate::generate, transform::transform};
+//! # luaify
+//!
+//! A Rust for generating Lua code from Rust syntax.
+use crate::{
+    generate::{generate, generate_chunk},
+    transform::{transform, transform_chunk},
+};
 use proc_macro::TokenStream as TokenStream1;
 use quote::ToTokens;
 use syn::parse_macro_input;
@@ -16,3 +22,13 @@ pub fn luaify(input: TokenStream1) -> TokenStream1 {
    }
    .into()
 }
+
+#[proc_macro]
+pub fn luaify_chunk(input: TokenStream1) -> TokenStream1 {
+    let mut block = parse_macro_input!(input);
+    match transform_chunk(&mut block).and_then(|()| generate_chunk(&block)) {
+        Ok(s) => s,
+        Err(err) => err.into_compile_error().into_token_stream(),
+    }
+    .into()
+}
--- a/crates/luaify/src/transform.rs
+++ b/crates/luaify/src/transform.rs
@@ -1,6 +1,4 @@
-use crate::utils::{LuaType, expr_ident, pat_ident, syn_error, wrap_expr_block};
-use quote::format_ident;
-use std::mem;
+use crate::utils::syn_error;
 use syn::{spanned::*, visit_mut::*, *};

 pub fn transform(expr: &mut Expr) -> Result<()> {
@@ -9,6 +7,12 @@ pub fn transform(expr: &mut Expr) -> Result<()> {
    visitor.result
 }

+pub fn transform_chunk(block: &mut Block) -> Result<()> {
+    let mut visitor = Visitor::new();
+    visitor.visit_block_mut(block);
+    visitor.result
+}
+
 #[derive(Debug)]
 struct Visitor {
    result: Result<()>,
@@ -21,27 +25,6 @@ impl Visitor {
 }

 impl VisitMut for Visitor {
-    fn visit_expr_closure_mut(&mut self, clo: &mut ExprClosure) {
-        match self.transform_expr_closure(clo) {
-            res @ Err(_) => self.result = res,
-            _ => visit_expr_closure_mut(self, clo),
-        }
-    }
-
-    fn visit_item_fn_mut(&mut self, func: &mut ItemFn) {
-        match self.transform_function(func) {
-            res @ Err(_) => self.result = res,
-            _ => visit_item_fn_mut(self, func),
-        }
-    }
-
-    fn visit_expr_mut(&mut self, expr: &mut Expr) {
-        match self.transform_expr(expr) {
-            res @ Err(_) => self.result = res,
-            _ => visit_expr_mut(self, expr),
-        }
-    }
-
    fn visit_expr_unary_mut(&mut self, un: &mut ExprUnary) {
        match self.transform_unary(un) {
            res @ Err(_) => self.result = res,
@@ -58,147 +41,9 @@ impl VisitMut for Visitor {
 }

 impl Visitor {
-    fn transform_expr_closure(&mut self, clo: &mut ExprClosure) -> Result<()> {
-        //
-        // transforms a closure expression with input type annotations by removing the annotations
-        // and inserting `as` casts at the start.
-        //
-        // before:
-        //    |a: string, b: number| { ... }
-        // after:
-        //    |a, b| { a as string; b as number; ... }
-        //
-        let mut checks: Vec<Stmt> = vec![];
-        for input in clo.inputs.iter_mut() {
-            match input {
-                Pat::Ident(_) => {}
-                Pat::Type(typed) => {
-                    let ident = pat_ident(&typed.pat)?;
-                    let ty = mem::replace(&mut typed.ty, parse_quote!(_));
-                    match (&*ty).try_into()? {
-                        LuaType::Any => {}
-                        _ => checks.push(parse_quote! { #ident as #ty; }),
-                    }
-                }
-                _ => {}
-            }
-        }
-
-        if !checks.is_empty() {
-            let mut body = wrap_expr_block(&clo.body);
-            body.stmts.splice(..0, checks);
-            clo.body = Box::new(parse_quote! { #body });
-        }
-
-        Ok(())
-    }
-
-    fn transform_function(&mut self, func: &mut ItemFn) -> Result<()> {
-        //
-        // transforms a function item with input type annotations by removing the annotations
-        // and inserting `as` casts at the start.
-        //
-        // before:
-        //    fn my_func(self: table, a: string) { ... }
-        // after:
-        //    fn my_func(self: _, a: _) { self as table; a as string; ... }
-        //
-        let mut checks: Vec<Stmt> = vec![];
-        for input in func.sig.inputs.iter_mut() {
-            if let Some((ident, ty)) = match input {
-                FnArg::Receiver(recv) if recv.colon_token.is_some() => {
-                    let ty = mem::replace(&mut recv.ty, parse_quote!(_));
-                    recv.colon_token = None;
-                    Some((Ident::new("self", recv.self_token.span()), ty))
-                }
-                FnArg::Typed(typed) => {
-                    let ident = pat_ident(&typed.pat)?;
-                    let ty = mem::replace(&mut typed.ty, parse_quote!(_));
-                    Some((ident, ty))
-                }
-                _ => None,
-            } {
-                match (&*ty).try_into()? {
-                    LuaType::Any => {}
-                    _ => checks.push(parse_quote! { #ident as #ty; }),
-                }
-            };
-        }
-
-        func.block.stmts.splice(..0, checks);
-        Ok(())
-    }
-
-    fn transform_expr(&mut self, expr: &mut Expr) -> Result<()> {
-        self.transform_expr_cast(expr)?;
-        Ok(())
-    }
-
-    fn transform_expr_cast(&mut self, expr: &mut Expr) -> Result<()> {
-        //
-        // transforms an `as` cast expression into a block expression containing a runtime
-        // lua type check.
-        //
-        // before:
-        //    var as string
-        // after:
-        //    { if type(var) != "string" { error(...) } }
-        //
-        if let Expr::Cast(cast) = expr {
-            let arg = (*cast.expr).clone();
-            let mut prelude: Option<Stmt> = None;
-            let ty: LuaType = (&*cast.ty).try_into()?;
-            let ty_str = format!("{ty}");
-            let (ident, msg) = match expr_ident(&arg) {
-                Ok(ident) => (ident.clone(), format!("{ty} expected in '{ident}', got ")),
-                Err(_) => {
-                    let ident = Ident::new("_", arg.span());
-                    prelude = Some(parse_quote! { let #ident = #arg; });
-                    (ident, format!("{ty} expected, got "))
-                }
-            };
-
-            let tmp = format_ident!("__{ident}");
-            let span = cast.span();
-            *expr = match ty {
-                LuaType::Any => parse_quote_spanned!(span => {}),
-                LuaType::Nil => parse_quote_spanned!(span => {
-                    #prelude
-                    assert(#ident == (), concat!(#msg, r#type(#ident)));
-                }),
-                LuaType::Number => parse_quote_spanned!(span => {
-                    #prelude
-                    let #tmp = #ident;
-                    #ident = tonumber(#ident);
-                    assert(#ident != (), concat!(#msg, r#type(#tmp)));
-                }),
-                LuaType::Integer => parse_quote_spanned!(span => {
-                    #prelude
-                    let #tmp = #ident;
-                    #ident = tonumber(#ident);
-                    assert(#ident != () && math::floor(#ident) == #ident, concat!(#msg, r#type(#tmp)));
-                }),
-                LuaType::String => parse_quote_spanned!(span => {
-                    #prelude
-                    if r#type(#ident) == "number" {
-                        #ident = tostring(#ident);
-                    } else {
-                        assert(r#type(#ident) == "string", concat!(#msg, r#type(#ident)));
-                    }
-                }),
-                _ => parse_quote_spanned!(span => {
-                    #prelude
-                    assert(r#type(#ident) == #ty_str, concat!(#msg, r#type(#ident)));
-                }),
-            }
-        }
-
-        Ok(())
-    }
-
    fn transform_unary(&mut self, un: &mut ExprUnary) -> Result<()> {
        //
-        // separates a nested negation unary operator with parentheses, because double hyphen
+        // separates a nested negation unary operator with parentheses, because the double hyphen
        // `--` indicates a comment in lua.
        //
        // before:
@@ -210,7 +55,7 @@ impl Visitor {
            && let Expr::Unary(ref inner) = *un.expr
            && let UnOp::Neg(_) = inner.op
        {
-            un.expr = Box::new(parse_quote!((#inner)));
+            un.expr = Box::new(parse_quote_spanned!(inner.span() => (#inner)));
        }

        Ok(())
--- a/crates/luaify/src/utils.rs
+++ b/crates/luaify/src/utils.rs
@@ -1,5 +1,4 @@
-use std::fmt;
-use syn::{ext::*, spanned::*, *};
+use syn::*;

 macro_rules! syn_error {
    ($src:expr, $($fmt:expr),+) => {{
@@ -24,90 +23,3 @@ pub fn wrap_expr_block(expr: &Expr) -> Block {
        expr => parse_quote!({ #expr }),
    }
 }
-
-pub fn expr_ident(expr: &Expr) -> Result<&Ident> {
-    match expr {
-        Expr::Path(path) => path.path.require_ident(),
-        _ => syn_error!(expr, "expected ident"),
-    }
-}
-
-pub fn pat_ident(pat: &Pat) -> Result<Ident> {
-    Ok(match pat {
-        Pat::Ident(ident) => match ident.subpat {
-            Some((_, ref subpat)) => syn_error!(subpat, "unexpected subpattern"),
-            None => ident.ident.clone(),
-        },
-        Pat::Wild(wild) => Ident::new("_", wild.span()),
-        _ => syn_error!(pat, "expected ident"),
-    })
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum LuaType {
-    Any,
-    Nil,
-    Boolean,
-    Lightuserdata,
-    Number,
-    Integer,
-    String,
-    Table,
-    Function,
-    Userdata,
-    Thread,
-    Cdata,
-}
-
-impl fmt::Display for LuaType {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match self {
-            LuaType::Any => write!(f, "any"),
-            LuaType::Nil => write!(f, "nil"),
-            LuaType::Boolean => write!(f, "boolean"),
-            LuaType::Lightuserdata => write!(f, "lightuserdata"),
-            LuaType::Number => write!(f, "number"),
-            LuaType::Integer => write!(f, "integer"),
-            LuaType::String => write!(f, "string"),
-            LuaType::Table => write!(f, "table"),
-            LuaType::Function => write!(f, "function"),
-            LuaType::Userdata => write!(f, "userdata"),
-            LuaType::Thread => write!(f, "thread"),
-            LuaType::Cdata => write!(f, "cdata"),
-        }
-    }
-}
-
-impl TryFrom<&Ident> for LuaType {
-    type Error = Error;
-
-    fn try_from(value: &Ident) -> Result<Self> {
-        Ok(match format!("{}", value.unraw()).as_str() {
-            "any" => Self::Any,
-            "nil" => Self::Nil,
-            "boolean" => Self::Boolean,
-            "lightuserdata" => Self::Lightuserdata,
-            "number" => Self::Number,
-            "integer" => Self::Integer,
-            "string" => Self::String,
-            "table" => Self::Table,
-            "function" => Self::Function,
-            "userdata" => Self::Userdata,
-            "thread" => Self::Thread,
-            "cdata" => Self::Cdata,
-            _ => syn_error!(value, "invalid lua type"),
-        })
-    }
-}
-
-impl TryFrom<&Type> for LuaType {
-    type Error = Error;
-
-    fn try_from(value: &Type) -> Result<Self> {
-        match value {
-            Type::Infer(_) => Ok(Self::Any),
-            Type::Path(path) if path.qself.is_none() => path.path.require_ident()?.try_into(),
-            _ => syn_error!(value, "invalid lua type"),
-        }
-    }
-}
--- a/crates/luaify/tests/test.rs
+++ b/crates/luaify/tests/test.rs
@@ -1,4 +1,5 @@
-use luaify::luaify;
+use luaify::{luaify, luaify_chunk};
+use pretty_assertions::assert_eq;

 #[test]
 fn raw_ident() {
@@ -76,13 +77,6 @@ fn local_fn() {
        }),
        r#"function(a,b)local function inner(c,d)end;return inner;end"#
    );
-    assert_eq!(
-        luaify!(|| {
-            fn check(self: string, arg: number) {}
-            inner
-        }),
-        r#"function()local function check(self,arg)do if type(self)=="number"then self=tostring(self);else assert(type(self)=="string","string expected in \'self\', got "..type(self));end;end;do local __arg=arg;arg=tonumber(arg);assert(arg~=nil,"number expected in \'arg\', got "..type(__arg));end;end;return inner;end"#
-    );
 }

 #[test]
@@ -207,37 +201,6 @@ fn loops() {
    );
 }

-#[test]
-fn type_checks() {
-    assert_eq!(luaify!(|s| {}), r#"function(s)end"#);
-    assert_eq!(
-        luaify!(|s: table| {}),
-        r#"function(s)do assert(type(s)=="table","table expected in \'s\', got "..type(s));end;end"#
-    );
-    assert_eq!(
-        luaify!(|s| { s as string }),
-        r#"function(s)do if type(s)=="number"then s=tostring(s);else assert(type(s)=="string","string expected in \'s\', got "..type(s));end;end;end"#
-    );
-    assert_eq!(
-        luaify!(|s| { s as number }),
-        r#"function(s)do local __s=s;s=tonumber(s);assert(s~=nil,"number expected in \'s\', got "..type(__s));end;end"#
-    );
-    assert_eq!(
-        luaify!(|s| { s as nil }),
-        r#"function(s)do assert(s==nil,"nil expected in \'s\', got "..type(s));end;end"#
-    );
-    assert_eq!(luaify!(|s| { s as any }), r#"function(s)do end;end"#);
-
-    assert_eq!(
-        luaify!(|s| {
-            let (ok, res) = coroutine::r#yield(thread);
-            ok as boolean;
-            res as nil;
-        }),
-        r#"function(s)local ok,res=coroutine.yield(thread);do assert(type(ok)=="boolean","boolean expected in \'ok\', got "..type(ok));end;do assert(res==nil,"nil expected in \'res\', got "..type(res));end;end"#
-    );
-}
-
 #[test]
 fn concat() {
    assert_eq!(luaify!(concat!(a)), r#"a"#);
@@ -402,3 +365,19 @@ fn length() {
        r#"local a,b,c=#a,#b,#c;"#
    );
 }
+
+#[test]
+fn chunk() {
+    assert_eq!(
+        luaify_chunk!({
+            if a == b {
+                c()
+            } else if b == c {
+                a()
+            } else {
+                d()
+            }
+        }),
+        "if a==b then c();elseif b==c then a();else d();end;"
+    );
+}
--- a/crates/luajit/Cargo.toml
+++ b/crates/luajit/Cargo.toml
@@ -16,4 +16,3 @@ bitflags = { version = "2.9.1", features = ["std"] }
 bstr = "1.12.0"
 luaffi = { path = "../luaffi" }
 luajit-sys = { path = "../luajit-sys" }
-thiserror = "2.0.12"
--- a/crates/luajit/src/lib.rs
+++ b/crates/luajit/src/lib.rs
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,2 +1,24 @@
+#[cfg(feature = "task")]
+pub use lb::chan;
+#[cfg(feature = "fs")]
 pub use lb::fs;
+#[cfg(feature = "net")]
 pub use lb::net;
+#[cfg(feature = "task")]
+pub use lb::task;
+#[cfg(feature = "time")]
+pub use lb::time;
+
+#[doc(hidden)]
+pub fn open(#[allow(unused)] rt: &mut lb::runtime::Builder) {
+    #[cfg(feature = "task")]
+    rt.module::<task::lb_tasklib>();
+    #[cfg(feature = "task")]
+    rt.module::<chan::lb_chanlib>();
+    #[cfg(feature = "time")]
+    rt.module::<time::lb_timelib>();
+    #[cfg(feature = "fs")]
+    rt.module::<fs::lb_fslib>();
+    #[cfg(feature = "net")]
+    rt.module::<net::lb_netlib>();
+}
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,7 +1,8 @@
 use clap::Parser;
+use luajit::Chunk;
 use mimalloc::MiMalloc;
 use owo_colors::OwoColorize;
-use std::{backtrace::Backtrace, fmt::Display, net::SocketAddr, num::NonZero, panic, thread};
+use std::{backtrace::Backtrace, fmt::Display, num::NonZero, panic, process, thread};
 use sysexits::ExitCode;

 #[global_allocator]
@@ -20,24 +21,42 @@ fn panic_cb(panic: &panic::PanicHookInfo) {
    };

    eprint!(
-        "{}:\n{trace}",
+        "{}\n{trace}",
        format_args!(
            "thread '{}' panicked at {location}: {msg}",
            thread::current().name().unwrap_or("<unnamed>")
        )
        .red()
+        .bold()
    );

    eprintln!(
        "{}",
        format_args!(
-            "This is a bug in luby. Please kindly report this at {}.",
+            "luby should never panic. Please kindly report this bug at {}.",
            env!("CARGO_PKG_REPOSITORY")
        )
        .yellow()
+        .bold()
    );
 }

+fn error_cb(err: &luajit::Error) {
+    match err.trace() {
+        Some(trace) => eprintln!("{}\n{trace}", err.red().bold()),
+        None => eprintln!("{}", err.red().bold()),
+    }
+
+    process::exit(1);
+}
+
+fn unwrap_exit<T, E: Display>(code: ExitCode) -> impl FnOnce(E) -> T {
+    move |err| {
+        eprintln!("{}", err.red().bold());
+        code.exit()
+    }
+}
+
 #[derive(Debug, Parser)]
 struct Args {
    /// Paths to scripts to execute.
@@ -60,12 +79,21 @@ struct Args {
    #[clap(long, short = 'j', help_heading = "Runtime", value_name = "CMD=FLAGS")]
    jit: Vec<String>,

+    /// Allow global variables.
+    #[clap(
+        long,
+        help_heading = "Runtime",
+        value_name = "ENABLED",
+        default_value_t = true
+    )]
+    allow_globals: bool,
+
    /// Number of worker threads.
    #[clap(
        long,
        short = 'T',
        help_heading = "Runtime",
-        value_name = "THREADS",
+        value_name = "COUNT",
        default_value_t = Self::threads()
    )]
    threads: NonZero<usize>,
@@ -74,16 +102,18 @@ struct Args {
    #[clap(
        long,
        help_heading = "Runtime",
-        value_name = "THREADS",
+        value_name = "COUNT",
        default_value_t = Self::blocking_threads()
    )]
    blocking_threads: NonZero<usize>,

    /// Enable tokio-console integration.
-    #[clap(long, help_heading = "Debugging")]
+    #[cfg(feature = "tokio-console")]
+    #[clap(long, help_heading = "Debugging", value_name = "ENABLED")]
    enable_console: bool,

    /// tokio-console publish address.
+    #[cfg(feature = "tokio-console")]
    #[clap(
        long,
        help_heading = "Debugging",
@@ -91,7 +121,16 @@ struct Args {
        default_value = "127.0.0.1:6669",
        requires = "enable_console"
    )]
-    console_addr: SocketAddr,
+    console_addr: std::net::SocketAddr,
+
+    /// Dump internal data.
+    #[clap(
+        long,
+        help_heading = "Debugging",
+        value_name = "DATA",
+        value_parser = ["cdef"]
+    )]
+    dump: Vec<String>,

    /// Print version.
    #[clap(long, short = 'V')]
@@ -108,19 +147,13 @@ impl Args {
    }
 }

-fn exit_err<T, E: Display>(code: ExitCode) -> impl FnOnce(E) -> T {
-    move |err| {
-        eprintln!("{}", err.red());
-        code.exit()
-    }
-}
-
-fn main() -> Result<(), ExitCode> {
+fn main() -> ExitCode {
    panic::set_hook(Box::new(panic_cb));

    let args = Args::parse();
    if args.version {
-        return Ok(print_version());
+        print_version();
+        return ExitCode::Ok;
    }

    init_logger(&args);
@@ -131,7 +164,10 @@ fn main() -> Result<(), ExitCode> {

    tokio.block_on(async {
        lua.await;
-        main.await.unwrap()
+        match main.await {
+            Ok(res) => res,
+            Err(err) => panic::resume_unwind(err.into_panic()),
+        }
    })
 }

@@ -149,7 +185,7 @@ fn print_version() {

 fn init_logger(args: &Args) {
    use tracing::level_filters::LevelFilter;
-    use tracing_subscriber::{Layer, util::*};
+    use tracing_subscriber::util::*;

    let log = tracing_subscriber::fmt()
        .compact()
@@ -163,61 +199,80 @@ fn init_logger(args: &Args) {
        .with_target(false)
        .finish();

-    if args.enable_console {
+    #[cfg(feature = "tokio-console")]
+    {
+        use tracing_subscriber::Layer;
        console_subscriber::ConsoleLayer::builder()
            .with_default_env()
            .server_addr(args.console_addr)
            .spawn()
            .with_subscriber(log)
-            .init()
-    } else {
-        log.init()
+            .init();
    }
+
+    #[cfg(not(feature = "tokio-console"))]
+    log.init();
 }

 fn init_tokio(args: &Args) -> tokio::runtime::Runtime {
-    let mut rt = match args.threads.get() {
+    match args.threads.get() {
        1 => tokio::runtime::Builder::new_current_thread(),
        n => {
            let mut rt = tokio::runtime::Builder::new_multi_thread();
            rt.worker_threads(n - 1);
            rt
        }
-    };
-
-    rt.enable_all()
+    }
+    .enable_all()
    .thread_name("luby")
    .max_blocking_threads(args.blocking_threads.get())
    .build()
-        .unwrap_or_else(exit_err(ExitCode::OsErr))
+    .unwrap_or_else(unwrap_exit(ExitCode::OsErr))
 }

 fn init_lua(args: &Args) -> lb::runtime::Runtime {
-    let rt = lb::runtime::Builder::new();
-    let mut rt = rt.build().unwrap_or_else(exit_err(ExitCode::Software));
+    let mut rt = {
+        let mut rt = lb::runtime::Builder::new();
+        luby::open(&mut rt);
+
+        if args.dump.iter().find(|s| *s == "cdef").is_some() {
+            print!("{}", rt.registry()); // for cdef debugging
+        }
+
+        rt.unhandled_error(error_cb)
+            .prohibit_globals(!args.allow_globals)
+            .build()
+            .unwrap()
+    };

    for arg in args.jit.iter() {
        let mut s = rt.guard();
-        if let Some((cmd, flags)) = parse_jitlib_cmd(arg)
-            && let Ok(_) = s.require(format!("jit.{cmd}"), 1)
+        let res = if let Some((cmd, flags)) = parse_jitlib_cmd(arg)
+            && let Ok(_) = s.require(format!("jit.{cmd}"), Some(1))
        {
-            (s.push("start"), s.get(-2), s.push(flags));
-            s.call(1, 0)
+            (s.push("start"), s.get(-2));
+            s.push(flags);
+            s.call(1, Some(0)) // require("jit.{cmd}").start(flags)
        } else {
-            s.require("jit", 1).unwrap();
+            s.require("jit", Some(1)).unwrap();
            match arg.as_str() {
                cmd @ ("on" | "off" | "flush") => {
                    (s.push(cmd), s.get(-2));
-                    s.call(0, 0)
+                    s.call(0, Some(0)) // require("jit").[on/off/flush]()
                }
-                arg => {
+                flags => {
                    (s.push("opt"), s.get(-2));
-                    (s.push("start"), s.get(-2), s.push(arg));
-                    s.call(1, 0)
+                    (s.push("start"), s.get(-2));
+                    s.push(flags);
+                    s.call(1, Some(0)) // require("jit").opt.start(flags)
                }
            }
+        };
+
+        if let Err(err) = res {
+            drop(s);
+            rt.report_error(&err);
        }
-        .unwrap_or_else(exit_err(ExitCode::Usage));
    }

    rt
@@ -225,36 +280,29 @@ fn init_lua(args: &Args) -> lb::runtime::Runtime {

 fn parse_jitlib_cmd(s: &str) -> Option<(&str, &str)> {
    match s {
-        "p" => Some(("p", "Flspv10")),
-        "v" => Some(("v", "-")),
-        "dump" => Some(("dump", "tirs")),
+        "p" => Some(("p", "Flspv10")),    // default -jp flags
+        "v" => Some(("v", "-")),          // default -jv flags
+        "dump" => Some(("dump", "tirs")), // default -jdump flags
        _ => s.split_once('='),
    }
 }

-async fn main_async(args: Args, state: &mut luajit::State) -> Result<(), ExitCode> {
+async fn main_async(args: Args, cx: &mut lb::runtime::Context) -> ExitCode {
    for ref path in args.path {
-        let mut s = state.guard();
        let chunk = match std::fs::read(path) {
            Ok(chunk) => chunk,
            Err(err) => {
-                eprintln!("{}", format_args!("{path}: {err}").red());
-                ExitCode::NoInput.exit();
+                eprintln!("{}", format_args!("{path}: {err}").red().bold());
+                return ExitCode::NoInput;
            }
        };

-        s.load(&luajit::Chunk::new(chunk).path(path))
-            .unwrap_or_else(exit_err(ExitCode::NoInput));
-
-        if let Err(err) = s.call_async(0, 0).await {
-            match err.trace() {
-                Some(trace) => eprintln!("{}\n{trace}", err.red()), // runtime error
-                None => eprintln!("{}", err.red()),
-            }
-
-            ExitCode::DataErr.exit();
+        if let Err(ref err) = cx.load(&Chunk::new(chunk).with_path(path)) {
+            cx.report_error(err);
+        } else if let Err(ref err) = cx.call_async(0, Some(0)).await {
+            cx.report_error(err);
        }
    }

-    Ok(())
+    ExitCode::Ok
 }
--- a/test.lua
+++ b/test.lua
@@ -1,6 +0,0 @@
-local ffi = require("ffi")
-local lb = ffi.new("struct lb_core")
-
-print(lb)
-
-lb.spawn("")
--- a/tests/main.lua
+++ b/tests/main.lua
@@ -0,0 +1,157 @@
+if (...) ~= nil and (...).type == "group" then return end -- prevent recursive harness call
+
+local ok = pcall(require, "lb:task")
+if not ok then error("lua test harness requires 'lb:task'") end
+local ok, time = pcall(require, "lb:time")
+if not ok then error("lua test harness requires 'lb:time'") end
+local ok, fs = pcall(require, "lb:fs")
+if not ok then error("lua test harness requires 'lb:fs'") end
+
+local global = _G
+local color = {
+  reset = "\x1b[0m",
+  pass = "\x1b[32;1m", -- green
+  fail = "\x1b[31;1m", -- red
+}
+
+local icon = {
+  check = "\u{2713}",
+  cross = "\u{00d7}",
+  chevron = "\u{203a}",
+}
+
+local function style(name, s)
+  return ("%s%s%s"):format(color[name], s, color.reset)
+end
+
+local function create_test(name, f, group)
+  local test = { type = "test", name = name or "", group = group, state = "pending", f = f }
+  local fenv = setmetatable({}, { __index = global, __newindex = global })
+  setfenv(f, fenv)
+  return test
+end
+
+local function create_group(name, f, parent)
+  local group = { type = "group", name = name or "", parent = parent, items = {} }
+  local fenv = setmetatable({
+    describe = function(name, f)
+      local item = create_group(name, f, group)
+      table.insert(group.items, item)
+      return item
+    end,
+
+    test = function(name, f)
+      local item = create_test(name, f, group)
+      table.insert(group.items, item)
+      return item
+    end,
+  }, { __index = global, __newindex = global })
+
+  setfenv(f, fenv)
+  f(group)
+  return group
+end
+
+local function name_test(test)
+  local name = test.name
+  local group = test.group
+  while group ~= nil do
+    if group.name ~= "" then name = ("%s %s %s"):format(group.name, icon.chevron, name) end
+    group = group.parent
+  end
+  return name
+end
+
+local function trace(msg)
+  return style("fail", msg) .. debug.traceback("", 2):sub(("\nstack traceback:"):len() + 1)
+end
+
+local function run_test(test)
+  local ok, res = xpcall(test.f, trace, test)
+  if ok then
+    test.state = "pass"
+    print("", ("%s %s"):format(style("pass", "PASS"), name_test(test)))
+  else
+    test.state = "fail"
+    print("", ("%s %s\n\n%s\n"):format(style("fail", "FAIL"), name_test(test), res))
+  end
+  collectgarbage() -- gc after each test to test destructors
+  return test
+end
+
+local function start(cx, item)
+  if item.type == "test" then
+    table.insert(cx.tasks, spawn(run_test, item))
+  elseif item.type == "group" then
+    for _, item in ipairs(item.items) do
+      start(cx, item)
+    end
+  end
+end
+
+local function check_refs()
+  -- ensure all refs were properly unref'ed
+  local registry = debug.getregistry()
+  local count = #registry
+  local ref = 0 -- FREELIST_REF
+  while type(registry[ref]) == "number" do
+    local next = registry[ref]
+    registry[ref], ref = nil, next
+  end
+  for i = 1, count do
+    local value = registry[i]
+    if type(value) ~= "thread" then -- ignore threads pinned by the runtime
+      assert(rawequal(registry[i], nil), ("ref %d not unref'ed: %s"):format(i, registry[i]))
+    end
+  end
+end
+
+local function main(item)
+  local cx = { tasks = {} }
+  local time, pass, fail = time.instant(), 0, 0
+  start(cx, item)
+  for _, task in ipairs(cx.tasks) do
+    if task:await().state == "pass" then
+      pass = pass + 1
+    else
+      fail = fail + 1
+    end
+  end
+  local elapsed = time:elapsed()
+  local code = 1
+  if fail == 0 then
+    print("", style("pass", ("%s %d tests passed"):format(icon.check, pass)))
+    code = 0
+  else
+    print(
+      "",
+      ("%s, %s"):format(
+        style("pass", ("%s %d tests passed"):format(icon.check, pass)),
+        style("fail", ("%s %d tests failed"):format(icon.cross, fail))
+      )
+    )
+  end
+  if elapsed < 1000 then
+    print("", ("%s completed in %.2f ms"):format(icon.chevron, elapsed * 1000))
+  else
+    print("", ("%s completed in %.2f s"):format(icon.chevron, elapsed))
+  end
+  cx = nil
+  collectgarbage()
+  check_refs()
+  return code -- report error to cargo
+end
+
+return main(create_group("", function()
+  local function include(path, pat)
+    for entry in fs.glob_dir(path, pat) do
+      local path = entry:path()
+      local f, err = loadfile(path)
+      if not f then error(err) end
+      describe(path, f)
+    end
+  end
+
+  include("tests", "**/*.lua")
+  include("crates", "*/tests/**/*.lua")
+end))
--- a/tests/main.rs
+++ b/tests/main.rs
@@ -0,0 +1,50 @@
+use luajit::Chunk;
+use owo_colors::OwoColorize;
+use std::{
+    fs, panic,
+    process::{self, ExitCode},
+};
+
+fn main() -> ExitCode {
+    let tokio = tokio::runtime::Runtime::new().unwrap();
+    let lua = {
+        let mut rt = lb::runtime::Builder::new();
+        luby::open(&mut rt);
+        rt.unhandled_error(error_cb)
+            .prohibit_globals(true)
+            .build()
+            .unwrap()
+    };
+
+    let path = "tests/main.lua";
+    let main = lua.spawn(async move |s| {
+        if let Err(ref err) = s.load(&Chunk::new(fs::read(path).unwrap()).with_path(path)) {
+            s.report_error(err);
+        } else if let Err(ref err) = s.call_async(0, Some(1)).await {
+            s.report_error(err);
+        }
+
+        if s.slot(1).integer().unwrap_or(1) == 0 {
+            ExitCode::SUCCESS
+        } else {
+            ExitCode::FAILURE
+        }
+    });
+
+    tokio.block_on(async move {
+        lua.await;
+        match main.await {
+            Ok(res) => res,
+            Err(err) => panic::resume_unwind(err.into_panic()),
+        }
+    })
+}
+
+fn error_cb(err: &luajit::Error) {
+    match err.trace() {
+        Some(trace) => eprintln!("{}\n{trace}", err.red().bold()),
+        None => eprintln!("{}", err.red().bold()),
+    }
+
+    process::exit(1);
+}
Author	SHA1	Message	Date
luaneko	5c257b0f74	Update luajit crate docs	2025-06-30 06:24:37 +10:00
luaneko	1808bee82a	Refactor and overhaul luajit crate	2025-06-30 05:59:54 +10:00
luaneko	7768c5ec56	Add basic timing library	2025-06-29 18:06:56 +10:00
luaneko	fcdee34b42	Fix doc errors	2025-06-29 17:58:34 +10:00
luaneko	5846220e35	Make bacon watch lua files too	2025-06-29 17:48:56 +10:00
luaneko	b0efc9f783	Report test complete time	2025-06-28 21:31:42 +10:00
luaneko	8c406a46b3	Correctly handle tcp disconnections	2025-06-28 21:11:09 +10:00
luaneko	263ca1cf48	Add basic tcp listener test	2025-06-28 20:00:01 +10:00
luaneko	505364a661	Check argument against negative sleep duration	2025-06-28 19:59:37 +10:00
luaneko	d5e85f2c30	Fix race condition in task state table unref	2025-06-28 19:52:28 +10:00
luaneko	cea9bc0813	Add lb_tcpsocket test	2025-06-28 17:21:28 +10:00
luaneko	85ed0d8318	Add more tests for task spawn	2025-06-28 17:21:19 +10:00
luaneko	eaa40ff3bc	Fix all borrow errors	2025-06-28 17:20:40 +10:00
luaneko	124e9bedfe	Implement lb_tcpstream	2025-06-28 15:42:16 +10:00
luaneko	a2cbb24a75	Turns out &mut T: FromFfi was unsound from the beginning after all	2025-06-28 15:06:32 +10:00
luaneko	36300b07d3	Fix __eq metamethods throwing on type mismatch	2025-06-28 11:10:29 +10:00
luaneko	db9d611ff7	Use raw equality for nil comparisons	2025-06-28 09:51:50 +10:00
luaneko	a90c36a260	Add more doc to net	2025-06-28 09:36:19 +10:00
luaneko	c760d12c39	Rewrite stab generation to be more extensible	2025-06-28 07:58:52 +10:00
luaneko	ef811ecfa9	Use faster fxhashset in registry	2025-06-28 06:06:39 +10:00
luaneko	d9ef6c7806	All internal library functions should be prefixed	2025-06-28 06:03:12 +10:00
luaneko	27c40c3244	All library functions no longer require self	2025-06-28 05:58:29 +10:00
luaneko	ccae0046fb	Improve cdef loading time by trimming unnecessary ctype caching	2025-06-28 05:29:19 +10:00
luaneko	e027623d40	Future destructor doesn't need to return nothing from drop	2025-06-28 05:22:59 +10:00
luaneko	8a49321110	Don't need to fully name option and result structs	2025-06-28 04:32:53 +10:00
luaneko	c70b043281	Fix main printing unnecessary ExitCode Debug impl	2025-06-28 04:18:00 +10:00
luaneko	f6b91cde10	Remove type checking transformation in luaify	2025-06-28 04:15:42 +10:00
luaneko	e05e2f4cb3	Implement the foundations for annotation generation	2025-06-28 04:15:27 +10:00
luaneko	6a4c726965	Properly report panic by resuming unwind	2025-06-28 04:11:33 +10:00
luaneko	5f1f6dab7a	Improve doc	2025-06-27 23:47:52 +10:00
luaneko	a760beabc1	Extern "Lua" functions should be able to act as constructors	2025-06-27 23:04:05 +10:00
luaneko	5ea532f1c6	Pretty icons	2025-06-27 14:41:19 +10:00
luaneko	c07ec4c3ad	Add headings	2025-06-27 14:31:49 +10:00
luaneko	7c40fb4322	Report number of passing and failing tests	2025-06-27 14:28:08 +10:00
luaneko	eb7b05d07a	Avoid globbing target dir every test	2025-06-27 04:45:53 +10:00
luaneko	3a7f2366e4	Ensure spawn order is consistent	2025-06-27 04:29:11 +10:00
luaneko	8443c44671	Test that task properly unrefs its table	2025-06-27 04:24:10 +10:00
luaneko	72b3afaeea	Add sleep test	2025-06-27 04:11:31 +10:00
luaneko	503985269a	Don't need to run all tests in workspace in bacon	2025-06-27 04:06:45 +10:00
luaneko	0839e7ce9a	Add task spawn tests	2025-06-27 04:06:35 +10:00
luaneko	cdfb2522ac	Add tempdir support	2025-06-27 03:53:08 +10:00
luaneko	0c4639c3e9	Add basic tcp socket test	2025-06-27 03:29:29 +10:00
luaneko	4f548bf9e9	More descriptive parameters	2025-06-27 03:18:25 +10:00
luaneko	40829cdfc6	Implement basic lua test harness	2025-06-27 03:11:49 +10:00
luaneko	db4faea821	Implement walk_dir and more robust globbing	2025-06-27 01:36:08 +10:00
luaneko	2964ebbe1b	Add basic glob function	2025-06-26 23:56:09 +10:00
luaneko	b1572cc9f1	Rename lsdir to read_dir and dirent to dir_entry	2025-06-26 23:24:48 +10:00
luaneko	862fcfe891	Add links to lua pdf in metamethod doc	2025-06-26 23:08:28 +10:00
luaneko	6a194e98e8	Document structs in fslib	2025-06-26 23:08:13 +10:00
luaneko	d2e06c9a70	Add stab tag for async functions	2025-06-26 22:58:30 +10:00
luaneko	679ffed807	Implement lsdir and file info functions	2025-06-26 22:46:27 +10:00
luaneko	549f96d4dc	Warn missing documentation	2025-06-26 21:32:38 +10:00
luaneko	09d7e51345	Add tokio/rt feature only if task feature is enabled	2025-06-26 21:10:07 +10:00
luaneko	8a74ade6a6	Implement task handle awaiting	2025-06-26 20:18:16 +10:00
luaneko	9338be7eb0	Add many lua annotation	2025-06-26 19:25:03 +10:00
luaneko	240e0111bf	Fix lua finaliser parameter check	2025-06-26 19:24:19 +10:00
luaneko	01f459ffaf	Implement task sleep function	2025-06-26 18:47:43 +10:00
luaneko	9b7dbcc141	Implement proper error handlign in spawned tasks	2025-06-26 18:47:31 +10:00
luaneko	24c5e9edc2	Include lb_tasklib::spawn in globals	2025-06-26 17:52:31 +10:00
luaneko	0cafac0948	Let modules decide their own name via #[cdef] macro	2025-06-26 17:47:21 +10:00
luaneko	1c1753234d	Rename MetatypeMethodBuilder to MetatypeFunctionBuilder	2025-06-26 17:12:00 +10:00
luaneko	31b5ff5ab9	Make all modules feature-gated to improve compile time	2025-06-26 16:54:58 +10:00
luaneko	2078dd0d8e	Delete test.lua	2025-06-26 13:57:45 +10:00
luaneko	dfd57e0ad0	Add macro to luaify blocks instead of exprs	2025-06-26 13:57:10 +10:00
luaneko	2a6015c19a	Use pretty assertions in luaify tests	2025-06-26 13:48:54 +10:00
luaneko	88ab48cddb	Modules should be registered in luby not lb	2025-06-26 13:46:39 +10:00
luaneko	bcb734846d	Implement lb_tcpsocket	2025-06-26 13:07:24 +10:00
luaneko	2fe9515702	Add newlines in generated cdef for readability	2025-06-26 13:06:39 +10:00
luaneko	f456a544e1	Disable all lualsp diagnostics in lib.lua	2025-06-26 13:05:50 +10:00
luaneko	ba969b9e56	Rename lb_libx to lb_xlib	2025-06-26 00:40:26 +10:00
luaneko	da5acd6bc8	Add stab tag for metamethods	2025-06-26 00:39:22 +10:00
luaneko	cbb47840e4	Alias stub types to rust types where possible	2025-06-25 23:16:42 +10:00
luaneko	2967513cbb	Allowing dumping generated cdef	2025-06-25 22:48:46 +10:00
luaneko	014687068f	Add file write operations	2025-06-25 22:26:43 +10:00
luaneko	85a0110e1a	Disable warnings in luaffi lib.lua	2025-06-25 22:19:17 +10:00
luaneko	91302db725	Print nicer error messages	2025-06-25 21:45:29 +10:00
luaneko	c249549b3c	Fix unknown feature warning	2025-06-25 21:25:02 +10:00
luaneko	30596d9331	Impl generic From/IntoFfi for Option	2025-06-25 21:24:24 +10:00
luaneko	530a1530ba	Call it library not module	2025-06-25 20:13:09 +10:00