All library functions no longer require self

Improve cdef loading time by trimming unnecessary ctype caching
Future destructor doesn't need to return nothing from drop
2025-06-28 05:58:29 +10:00 · 2025-06-28 05:29:19 +10:00 · 2025-06-28 05:22:59 +10:00 · 2025-06-28 04:32:53 +10:00 · 2025-06-28 04:18:00 +10:00 · 2025-06-28 04:15:42 +10:00
43 changed files with 2367 additions and 1147 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 +1050,15 @@ 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 +1123,6 @@ 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 +1154,7 @@ dependencies = [
 name = "luaify"
 version = "0.0.1"
 dependencies = [
+ "pretty_assertions",
 "proc-macro2",
 "quote",
 "syn",
@@ -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 +30,28 @@ repository.workspace = true
 dev.panic = "abort"
 release.panic = "abort"

+[[test]]
+name = "main"
+harness = false
+
+[features]
+default = ["task", "fs", "net"]
+task = ["lb/task"]
+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
@@ -1,7 +1,3 @@
-[jobs.test]
-command = ["cargo", "test", "--workspace"]
-need_stdout = true
-
 [jobs.doc]
 command = ["cargo", "doc", "--workspace"]

--- a/crates/lb/Cargo.toml
+++ b/crates/lb/Cargo.toml
@@ -7,15 +7,19 @@ authors.workspace = true
 homepage.workspace = true
 repository.workspace = true

+[features]
+runtime = ["tokio/rt"]
+task = ["tokio/rt", "tokio/time"]
+fs = ["tokio/fs", "dep:walkdir", "dep:globset", "dep:tempfile"]
+net = ["tokio/net"]
+
 [dependencies]
-camino = "1.1.10"
 derive_more = { version = "2.0.1", features = ["full"] }
+globset = { version = "0.4.16", optional = true }
 luaffi = { path = "../luaffi" }
 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) in Lua.
+///
+/// ```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 +1,429 @@
-//! 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 derive_more::From;
 use luaffi::{cdef, metatype};
-use std::io;
-use tokio::fs;
+use std::{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** in Lua. 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 {
+    /// 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) in Lua.
 ///
 /// ```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
+    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)
+    pub extern "Lua-C" fn read_sync(path: &str) -> Result<Vec<u8>> {
+        Ok(std::fs::read(path)?)
+    }
+
+    pub async extern "Lua-C" fn write(path: &str, contents: &[u8]) -> Result<()> {
+        Ok(tokio::fs::write(path, contents).await?)
+    }
+
+    pub extern "Lua-C" fn write_sync(path: &str, contents: &[u8]) -> Result<()> {
+        Ok(std::fs::write(path, contents)?)
+    }
+
+    pub async extern "Lua-C" fn read_dir(path: &str) -> Result<lb_read_dir> {
+        Ok(tokio::fs::read_dir(path).await?.into())
+    }
+
+    pub extern "Lua-C" fn read_dir_sync(path: &str) -> Result<lb_read_dir_sync> {
+        Ok(std::fs::read_dir(path)?.into())
+    }
+
+    pub extern "Lua-C" fn walk_dir(path: &str) -> lb_walk_dir {
+        walkdir::WalkDir::new(path).into_iter().into()
+    }
+
+    pub extern "Lua-C" fn glob(pattern: &str) -> Result<lb_glob_dir> {
+        Self::glob_dir(".", pattern)
+    }
+
+    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 {
+            iter,
+            matcher,
+            prefix,
+        })
+    }
+
+    pub extern "Lua-C" fn temp_dir() -> Result<lb_temp_dir> {
+        Ok(tempfile::tempdir()?.into())
+    }
+
+    pub extern "Lua-C" fn temp_dir_in(path: &str) -> Result<lb_temp_dir> {
+        Ok(tempfile::tempdir_in(path)?.into())
+    }
+}
+
+/// Iterator over the entries in a directory.
+#[derive(Debug, From)]
+#[cdef]
+pub struct lb_read_dir(#[opaque] tokio::fs::ReadDir);
+
+#[metatype]
+impl lb_read_dir {
+    #[call]
+    pub async extern "Lua-C" fn next(&mut self) -> Result<Option<lb_dir_entry>> {
+        Ok(self.0.next_entry().await?.map(Into::into))
+    }
+}
+
+/// Synchronous version of [`lb_read_dir`].
+#[derive(Debug, From)]
+#[cdef]
+pub struct lb_read_dir_sync(#[opaque] std::fs::ReadDir);
+
+#[metatype]
+impl lb_read_dir_sync {
+    #[call]
+    pub extern "Lua-C" fn next(&mut self) -> Result<Option<lb_dir_entry_sync>> {
+        Ok(self.0.next().transpose()?.map(Into::into))
+    }
+}
+
+/// Entry inside of a directory on the filesystem.
+#[derive(Debug, From)]
+#[cdef]
+pub struct lb_dir_entry(#[opaque] tokio::fs::DirEntry);
+
+#[metatype]
+impl lb_dir_entry {
+    pub extern "Lua-C" fn path(&self) -> String {
+        self.0.path().to_string_lossy().into()
+    }
+
+    pub extern "Lua-C" fn name(&self) -> String {
+        self.0.file_name().to_string_lossy().into()
+    }
+
+    pub async extern "Lua-C" fn r#type(&self) -> Result<lb_file_type> {
+        Ok(self.0.file_type().await?.into())
+    }
+
+    pub async extern "Lua-C" fn metadata(&self) -> Result<lb_file_meta> {
+        Ok(self.0.metadata().await?.into())
+    }
+
+    #[cfg(unix)]
+    pub extern "Lua-C" fn ino(&self) -> u64 {
+        self.0.ino()
+    }
+
+    #[tostring]
+    pub extern "Lua" fn tostring(&self) -> String {
+        self.path()
+    }
+}
+
+/// Synchronous version of [`lb_dir_entry`].
+#[derive(Debug, From)]
+#[cdef]
+pub struct lb_dir_entry_sync(#[opaque] std::fs::DirEntry);
+
+#[metatype]
+impl lb_dir_entry_sync {
+    pub extern "Lua-C" fn path(&self) -> String {
+        self.0.path().to_string_lossy().into()
+    }
+
+    pub extern "Lua-C" fn name(&self) -> String {
+        self.0.file_name().to_string_lossy().into()
+    }
+
+    pub extern "Lua-C" fn r#type(&self) -> Result<lb_file_type> {
+        Ok(self.0.file_type()?.into())
+    }
+
+    pub extern "Lua-C" fn metadata(&self) -> Result<lb_file_meta> {
+        Ok(self.0.metadata()?.into())
+    }
+
+    #[cfg(unix)]
+    pub extern "Lua-C" fn ino(&self) -> u64 {
+        use std::os::unix::fs::DirEntryExt;
+        self.0.ino()
+    }
+
+    #[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, From)]
+#[cdef]
+pub struct lb_file_type(#[opaque] std::fs::FileType);
+
+#[metatype]
+impl lb_file_type {
+    pub extern "Lua-C" fn is_dir(&self) -> bool {
+        self.0.is_dir()
+    }
+
+    pub extern "Lua-C" fn is_file(&self) -> bool {
+        self.0.is_file()
+    }
+
+    pub extern "Lua-C" fn is_symlink(&self) -> bool {
+        self.0.is_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, From)]
+#[cdef]
+pub struct lb_file_meta(#[opaque] std::fs::Metadata);
+
+#[metatype]
+impl lb_file_meta {
+    pub extern "Lua-C" fn is_dir(&self) -> bool {
+        self.0.is_dir()
+    }
+
+    pub extern "Lua-C" fn is_file(&self) -> bool {
+        self.0.is_file()
+    }
+
+    pub extern "Lua-C" fn is_symlink(&self) -> bool {
+        self.0.is_file()
+    }
+
+    pub extern "Lua-C" fn r#type(&self) -> lb_file_type {
+        self.0.file_type().into()
+    }
+
+    pub extern "Lua-C" fn size(&self) -> u64 {
+        self.0.len()
+    }
+
+    pub extern "Lua-C" fn perms(&self) -> lb_file_perms {
+        self.0.permissions().into()
+    }
+
+    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.))
+    }
+
+    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.))
+    }
+
+    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.))
+    }
+
+    #[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, From)]
+#[cdef]
+pub struct lb_file_perms(#[opaque] std::fs::Permissions);
+
+#[metatype]
+impl lb_file_perms {
+    pub extern "Lua-C" fn readonly(&self) -> bool {
+        self.0.readonly()
+    }
+
+    pub extern "Lua-C" fn set_readonly(&mut self, readonly: bool) {
+        self.0.set_readonly(readonly);
+    }
+}
+
+/// Iterator for recursively descending into a directory.
+#[derive(Debug, From)]
+#[cdef]
+pub struct lb_walk_dir(#[opaque] walkdir::IntoIter);
+
+#[metatype]
+impl lb_walk_dir {
+    #[call]
+    pub extern "Lua-C" fn next(&mut self) -> Result<Option<lb_walk_dir_entry>> {
+        Ok(self.0.next().transpose()?.map(Into::into))
+    }
+}
+
+/// Entry inside of a directory on the filesystem obtained from [`lb_walk_dir`].
+#[derive(Debug, From)]
+#[cdef]
+pub struct lb_walk_dir_entry(#[opaque] walkdir::DirEntry);
+
+#[metatype]
+impl lb_walk_dir_entry {
+    pub extern "Lua-C" fn path(&self) -> String {
+        self.0.path().to_string_lossy().into()
+    }
+
+    pub extern "Lua-C" fn name(&self) -> String {
+        self.0.file_name().to_string_lossy().into()
+    }
+
+    pub extern "Lua-C" fn r#type(&self) -> lb_file_type {
+        self.0.file_type().into()
+    }
+
+    pub extern "Lua-C" fn metadata(&self) -> Result<lb_file_meta> {
+        Ok(self.0.metadata()?.into())
+    }
+
+    pub extern "Lua-C" fn is_symlink(&self) -> bool {
+        self.0.path_is_symlink()
+    }
+
+    pub extern "Lua-C" fn depth(&self) -> u32 {
+        self.0.depth() as u32
+    }
+
+    #[cfg(unix)]
+    pub extern "Lua-C" fn ino(&self) -> u64 {
+        use walkdir::DirEntryExt;
+        self.0.ino()
+    }
+
+    #[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: walkdir::IntoIter,
+    #[opaque]
+    matcher: globset::GlobSet,
+    #[opaque]
+    prefix: PathBuf,
+}
+
+#[metatype]
+impl lb_glob_dir {
+    #[call]
+    pub extern "Lua-C" fn next(&mut self) -> Result<Option<lb_walk_dir_entry>> {
+        while let Some(res) = self.iter.next() {
+            let entry = res?;
+            let path = entry.path().strip_prefix(&self.prefix).unwrap();
+            if self.matcher.is_match(path) {
+                return Ok(Some(entry.into()));
+            }
+        }
+
+        Ok(None)
+    }
+}
+
+/// Directory in the filesystem that is automatically deleted when it is garbage-collected.
+#[derive(Debug, From)]
+#[cdef]
+pub struct lb_temp_dir(#[opaque] tempfile::TempDir);
+
+#[metatype]
+impl lb_temp_dir {
+    pub extern "Lua-C" fn path(&self) -> String {
+        self.0.path().to_string_lossy().into()
+    }
+
+    #[tostring]
+    pub extern "Lua" fn tostring(&self) -> String {
+        self.path()
    }
 }
--- a/crates/lb/src/lib.rs
+++ b/crates/lb/src/lib.rs
@@ -1,5 +1,12 @@
-pub mod channel;
+//! luby standard library
+#![warn(missing_docs)]
+#[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;
--- a/crates/lb/src/net.rs
+++ b/crates/lb/src/net.rs
@@ -1,56 +1,79 @@
-//! The `lb:net` module provides an asynchronous network API for creating TCP or UDP servers and
+//! # Networking library
+//!
+//! The `lb:net` library provides an asynchronous network API for creating TCP or UDP servers and
 //! clients.
 //!
-//! # Exports
+//! ## Exports
 //!
-//! See [`lb_libnet`] for items exported by this module.
+//! See [`lb_netlib`] for items exported by this library.
 use derive_more::{From, FromStr};
-use luaffi::{cdef, metatype};
+use luaffi::{cdef, marker::OneOf, metatype};
 use std::{
-    io,
    net::{AddrParseError, IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr},
+    time::Duration,
 };
+use thiserror::Error;
 use tokio::net::{TcpListener, TcpSocket, TcpStream};

-/// Items exported by the `lb:net` 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** in Lua. 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 {
+    /// I/O error.
+    #[error("{0}")]
+    Io(#[from] std::io::Error),
+    /// IP or socket address syntax error.
+    #[error("{0}")]
+    InvalidAddr(#[from] AddrParseError),
+    /// Socket was already converted and cannot be used anymore.
+    #[error("socket was already converted")]
+    SocketConsumed,
+}
+
+type Result<T> = std::result::Result<T, Error>;
+
+/// Items exported by the `lb:net` library.
+///
+/// This library can be acquired by calling
+/// [`require("lb:net")`](https://www.lua.org/manual/5.1/manual.html#pdf-require) in Lua.
 ///
 /// ```lua
 /// local net = require("lb:net");
 /// ```
-#[cdef]
-pub struct lb_libnet;
+#[cdef(module = "lb:net")]
+pub struct lb_netlib;

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

-    /// See [`Ipv4Addr::LOCALHOST`].
-    pub extern "Lua-C" fn localhost_v4(&self) -> lb_ipaddr {
+    /// An IPv4 address representing localhost: `127.0.0.1`
+    pub extern "Lua-C" fn localhost_v4() -> lb_ipaddr {
        lb_ipaddr(Ipv4Addr::LOCALHOST.into())
    }

-    /// See [`Ipv6Addr::LOCALHOST`].
-    pub extern "Lua-C" fn localhost_v6(&self) -> lb_ipaddr {
+    /// An IPv6 address representing localhost: `::1`
+    pub extern "Lua-C" fn localhost_v6() -> lb_ipaddr {
        lb_ipaddr(Ipv6Addr::LOCALHOST.into())
    }

-    /// See [`Ipv4Addr::UNSPECIFIED`].
-    pub extern "Lua-C" fn unspecified_v4(&self) -> lb_ipaddr {
+    /// An IPv4 address representing an unspecified address: `0.0.0.0`
+    pub extern "Lua-C" fn unspecified_v4() -> lb_ipaddr {
        lb_ipaddr(Ipv4Addr::UNSPECIFIED.into())
    }

-    /// See [`Ipv6Addr::UNSPECIFIED`].
-    pub extern "Lua-C" fn unspecified_v6(&self) -> lb_ipaddr {
+    /// An IPv6 address representing an unspecified address: `::`
+    pub extern "Lua-C" fn unspecified_v6() -> lb_ipaddr {
        lb_ipaddr(Ipv6Addr::UNSPECIFIED.into())
    }

-    /// See [`Ipv4Addr::BROADCAST`].
-    pub extern "Lua-C" fn broadcast_v4(&self) -> lb_ipaddr {
+    /// An IPv4 address representing the broadcast address: `255.255.255.255`
+    pub extern "Lua-C" fn broadcast_v4() -> lb_ipaddr {
        lb_ipaddr(Ipv4Addr::BROADCAST.into())
    }

@@ -59,22 +82,20 @@ impl lb_libnet {
    /// If `s` is an [`lb_ipaddr`], a copy of that value is returned. If `s` is an
    /// [`lb_socketaddr`], the IP address part of the socket address is returned. Otherwise, parses
    /// `s` as an IP address string. Both IPv4 or IPv6 addresses are supported.
-    ///
-    /// # Errors
-    ///
-    /// Throws if `s` cannot be parsed as an IP address.
-    pub extern "Lua" fn ipaddr(&self, s: any) -> lb_ipaddr {
-        if __istype(__ct.lb_ipaddr, s) {
-            __new(__ct.lb_ipaddr, s) // copy constructor
-        } else if __istype(__ct.lb_socketaddr, s) {
+    pub extern "Lua" fn ipaddr(
+        addr: OneOf<(&lb_ipaddr, &lb_socketaddr, &str)>,
+    ) -> Result<lb_ipaddr> {
+        if __istype(__ct.lb_ipaddr, addr) {
+            __new(__ct.lb_ipaddr, addr) // copy constructor
+        } else if __istype(__ct.lb_socketaddr, addr) {
            s.ip()
        } else {
-            self.__parse_ipaddr(s)
+            Self::__parse_ipaddr(addr)
        }
    }

-    extern "Lua-C" fn __parse_ipaddr(&self, s: &str) -> Result<lb_ipaddr, AddrParseError> {
-        s.parse()
+    extern "Lua-C" fn __parse_ipaddr(addr: &str) -> Result<lb_ipaddr> {
+        Ok(addr.parse()?)
    }

    /// Creates an [`lb_socketaddr`] from the given input.
@@ -86,56 +107,87 @@ impl lb_libnet {
    /// socket address string. Both IPv4 and IPv6 addresses are supported.
    ///
    /// If `port` is not specified, `0` is used as the default.
-    ///
-    /// # Errors
-    ///
-    /// Throws if `s` cannot be parsed as an IP or socket address.
-    pub extern "Lua" fn socketaddr(&self, s: any, port: any) -> lb_socketaddr {
+    pub extern "Lua" fn socketaddr(
+        addr: OneOf<(&lb_ipaddr, &lb_socketaddr, &str)>,
+        port: Option<u16>,
+    ) -> Result<lb_socketaddr> {
        if port != () {
-            self.__new_socketaddr(self.ipaddr(s), port)
+            Self::__new_skaddr(Self::ipaddr(addr), port)
        } else {
-            if __istype(__ct.lb_socketaddr, s) {
-                __new(__ct.lb_socketaddr, s) // copy constructor
-            } else if __istype(__ct.lb_ipaddr, s) {
-                self.__new_socketaddr(s, 0) // default port 0
+            if __istype(__ct.lb_socketaddr, addr) {
+                __new(__ct.lb_socketaddr, addr) // copy constructor
+            } else if __istype(__ct.lb_ipaddr, addr) {
+                Self::__new_skaddr(addr, 0) // default port 0
            } else {
-                self.__parse_socketaddr(s)
+                Self::__parse_skaddr(addr)
            }
        }
    }

-    extern "Lua-C" fn __new_socketaddr(&self, ip: &lb_ipaddr, port: u16) -> lb_socketaddr {
+    extern "Lua-C" fn __new_skaddr(ip: &lb_ipaddr, port: u16) -> lb_socketaddr {
        SocketAddr::new(ip.0, port).into()
    }

-    extern "Lua-C" fn __parse_socketaddr(&self, s: &str) -> Result<lb_socketaddr, AddrParseError> {
-        s.parse()
+    extern "Lua-C" fn __parse_skaddr(addr: &str) -> Result<lb_socketaddr> {
+        Ok(if let Ok(addr) = addr.parse() {
+            SocketAddr::new(addr, 0).into() // default port 0
+        } else {
+            addr.parse::<SocketAddr>()?.into()
+        })
    }

    /// Creates a new TCP socket configured for IPv4.
    ///
    /// See [`TcpSocket::new_v4`].
-    ///
-    /// # Errors
-    ///
-    /// Throws if an error was encountered during the socket creation.
-    pub extern "Lua-C" fn tcp_v4(&self) -> io::Result<lb_tcpsocket> {
-        TcpSocket::new_v4().map(lb_tcpsocket)
+    pub extern "Lua-C" fn tcp() -> Result<lb_tcpsocket> {
+        Ok(Some(TcpSocket::new_v4()?).into())
    }

    /// Creates a new TCP socket configured for IPv6.
    ///
    /// See [`TcpSocket::new_v6`].
-    ///
-    /// # Errors
-    ///
-    /// Throws if an error was encountered during the socket creation.
-    pub extern "Lua-C" fn tcp_v6(&self) -> io::Result<lb_tcpsocket> {
-        TcpSocket::new_v6().map(lb_tcpsocket)
+    pub extern "Lua-C" fn tcp6() -> Result<lb_tcpsocket> {
+        Ok(Some(TcpSocket::new_v6()?).into())
+    }
+
+    pub async extern "Lua" fn bind_tcp(
+        addr: OneOf<(&lb_ipaddr, &lb_socketaddr, &str)>,
+        port: Option<u16>,
+    ) -> Result<lb_tcpsocket> {
+        let addr = Self::socketaddr(addr, port);
+        let socket;
+        if addr.ip().is_v6() {
+            socket = Self::tcp6();
+        } else {
+            socket = Self::tcp();
+        }
+        socket.bind(addr);
+        socket
+    }
+
+    pub async extern "Lua" fn connect_tcp(
+        addr: OneOf<(&lb_ipaddr, &lb_socketaddr, &str)>,
+        port: Option<u16>,
+    ) -> Result<lb_tcpstream> {
+        let addr = Self::socketaddr(addr, port);
+        let socket;
+        if addr.ip().is_v6() {
+            socket = Self::tcp6();
+        } else {
+            socket = Self::tcp();
+        }
+        socket.connect(addr)
+    }
+
+    pub async extern "Lua" fn listen_tcp(
+        addr: OneOf<(&lb_ipaddr, &lb_socketaddr, &str)>,
+        port: Option<u16>,
+    ) -> Result<lb_tcplistener> {
+        Self::bind_tcp(addr, port).listen(1024)
    }
 }

-/// An IP address, either IPv4 or IPv6.
+/// IP address, either IPv4 or IPv6.
 ///
 /// # Example
 ///
@@ -143,7 +195,7 @@ impl lb_libnet {
 ///
 /// ```lua
 /// local net = require("lb:net");
-/// local addr = net:ipaddr("127.0.0.1"); -- ipv4 loopback address
+/// local addr = net.ipaddr("127.0.0.1"); -- ipv4 loopback address
 ///
 /// assert(addr:is_v4());
 /// assert(addr:is_loopback());
@@ -170,7 +222,7 @@ impl lb_ipaddr {
    }

    /// Returns the string `"v4"` if this is an IPv4 address or `"v6"` if this is an IPv6 address.
-    pub extern "Lua" fn family(&self) -> string {
+    pub extern "Lua" fn family(&self) -> String {
        if self.is_v6() { "v6" } else { "v4" }
    }

@@ -260,7 +312,7 @@ impl lb_ipaddr {
    }
 }

-/// A socket address, which is an IP address with a port number.
+/// Socket address, which is an IP address with a port number.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, From, FromStr)]
 #[cdef]
 pub struct lb_socketaddr(#[opaque] SocketAddr);
@@ -274,14 +326,17 @@ impl lb_socketaddr {

    /// Sets the IP part of this address.
    ///
-    /// This function accepts the same arguments as [`ipaddr`](lb_libnet::ipaddr).
-    pub extern "Lua" fn set_ip(&mut self, s: any) -> &mut Self {
-        if __istype(__ct.lb_ipaddr, s) {
-            self.__set_ip(s);
-        } else if __istype(__ct.lb_socketaddr, s) {
-            self.__set_ip(s.ip());
+    /// This function accepts the same arguments as [`ipaddr`](lb_netlib::ipaddr).
+    pub extern "Lua" fn set_ip(
+        &mut self,
+        addr: OneOf<(&lb_ipaddr, &lb_socketaddr, &str)>,
+    ) -> &mut Self {
+        if __istype(__ct.lb_ipaddr, addr) {
+            self.__set_ip(addr);
+        } else if __istype(__ct.lb_socketaddr, addr) {
+            self.__set_ip(addr.ip());
        } else {
-            self.__set_ip_parse(s);
+            self.__set_ip_parse(addr);
        }
        self
    }
@@ -290,8 +345,8 @@ impl lb_socketaddr {
        self.0.set_ip(ip.0);
    }

-    extern "Lua-C" fn __set_ip_parse(&mut self, s: &str) -> Result<(), AddrParseError> {
-        s.parse().map(|ip| self.0.set_ip(ip))
+    extern "Lua-C" fn __set_ip_parse(&mut self, addr: &str) -> Result<()> {
+        Ok(self.0.set_ip(addr.parse()?))
    }

    /// Returns the port part of this address.
@@ -300,7 +355,7 @@ impl lb_socketaddr {
    }

    /// Sets the port part of this address.
-    pub extern "Lua" fn set_port(&mut self, port: number) -> &mut Self {
+    pub extern "Lua" fn set_port(&mut self, port: u16) -> &mut Self {
        self.__set_port(port);
        self
    }
@@ -316,14 +371,127 @@ impl lb_socketaddr {
    }
 }

-/// A TCP socket which has not yet been converted to a [`lb_tcpstream`] or [`lb_tcplistener`].
+/// TCP socket which has not yet been converted to an [`lb_tcpstream`] or [`lb_tcplistener`].
 #[derive(Debug, From)]
 #[cdef]
-pub struct lb_tcpsocket(#[opaque] TcpSocket);
+pub struct lb_tcpsocket(#[opaque] Option<TcpSocket>);

 #[metatype]
-impl lb_tcpsocket {}
+impl lb_tcpsocket {
+    fn socket(&self) -> Result<&TcpSocket> {
+        self.0.as_ref().ok_or(Error::SocketConsumed)
+    }

+    /// See [`TcpSocket::keepalive`].
+    pub extern "Lua-C" fn keepalive(&self) -> Result<bool> {
+        Ok(self.socket()?.keepalive()?)
+    }
+
+    /// See [`TcpSocket::set_keepalive`].
+    pub extern "Lua-C" fn set_keepalive(&self, enabled: bool) -> Result<()> {
+        Ok(self.socket()?.set_keepalive(enabled)?)
+    }
+
+    /// See [`TcpSocket::reuseaddr`].
+    pub extern "Lua-C" fn reuseaddr(&self) -> Result<bool> {
+        Ok(self.socket()?.reuseaddr()?)
+    }
+
+    /// See [`TcpSocket::set_reuseaddr`].
+    pub extern "Lua-C" fn set_reuseaddr(&self, enabled: bool) -> Result<()> {
+        Ok(self.socket()?.set_reuseaddr(enabled)?)
+    }
+
+    /// See [`TcpSocket::reuseport`].
+    pub extern "Lua-C" fn reuseport(&self) -> Result<bool> {
+        Ok(self.socket()?.reuseport()?)
+    }
+
+    /// See [`TcpSocket::set_reuseport`].
+    pub extern "Lua-C" fn set_reuseport(&self, enabled: bool) -> Result<()> {
+        Ok(self.socket()?.set_reuseport(enabled)?)
+    }
+
+    /// See [`TcpSocket::send_buffer_size`].
+    pub extern "Lua-C" fn sendbuf(&self) -> Result<u32> {
+        Ok(self.socket()?.send_buffer_size()?)
+    }
+
+    /// See [`TcpSocket::set_send_buffer_size`].
+    pub extern "Lua-C" fn set_sendbuf(&self, size: u32) -> Result<()> {
+        Ok(self.socket()?.set_send_buffer_size(size)?)
+    }
+
+    /// See [`TcpSocket::recv_buffer_size`].
+    pub extern "Lua-C" fn recvbuf(&self) -> Result<u32> {
+        Ok(self.socket()?.recv_buffer_size()?)
+    }
+
+    /// See [`TcpSocket::set_recv_buffer_size`].
+    pub extern "Lua-C" fn set_recvbuf(&self, size: u32) -> Result<()> {
+        Ok(self.socket()?.set_recv_buffer_size(size)?)
+    }
+
+    /// See [`TcpSocket::linger`].
+    pub extern "Lua-C" fn linger(&self) -> Result<f64> {
+        Ok(self
+            .socket()?
+            .linger()?
+            .map(|n| n.as_secs_f64())
+            .unwrap_or(0.))
+    }
+
+    /// See [`TcpSocket::set_linger`].
+    pub extern "Lua-C" fn set_linger(&self, secs: f64) -> Result<()> {
+        Ok(self
+            .socket()?
+            .set_linger((secs != 0.).then_some(Duration::from_secs_f64(secs)))?)
+    }
+
+    /// See [`TcpSocket::nodelay`].
+    pub extern "Lua-C" fn nodelay(&self) -> Result<bool> {
+        Ok(self.socket()?.nodelay()?)
+    }
+
+    /// See [`TcpSocket::set_nodelay`].
+    pub extern "Lua-C" fn set_nodelay(&self, enabled: bool) -> Result<()> {
+        Ok(self.socket()?.set_nodelay(enabled)?)
+    }
+
+    /// See [`TcpSocket::tos`].
+    pub extern "Lua-C" fn tos(&self) -> Result<u32> {
+        Ok(self.socket()?.tos()?)
+    }
+
+    /// See [`TcpSocket::set_tos`].
+    pub extern "Lua-C" fn set_tos(&self, tos: u32) -> Result<()> {
+        Ok(self.socket()?.set_tos(tos)?)
+    }
+
+    /// See [`TcpSocket::local_addr`].
+    pub extern "Lua-C" fn local_addr(&self) -> Result<lb_socketaddr> {
+        Ok(self.socket()?.local_addr()?.into())
+    }
+
+    /// See [`TcpSocket::bind`].
+    pub extern "Lua-C" fn bind(&self, addr: &lb_socketaddr) -> Result<()> {
+        Ok(self.socket()?.bind(addr.0)?)
+    }
+
+    /// See [`TcpSocket::connect`].
+    pub async extern "Lua-C" fn connect(&mut self, addr: &lb_socketaddr) -> Result<lb_tcpstream> {
+        let socket = self.0.take().ok_or(Error::SocketConsumed)?;
+        Ok(socket.connect(addr.0).await?.into())
+    }
+
+    /// See [`TcpSocket::listen`].
+    pub extern "Lua-C" fn listen(&mut self, backlog: u32) -> Result<lb_tcplistener> {
+        let socket = self.0.take().ok_or(Error::SocketConsumed)?;
+        Ok(socket.listen(backlog)?.into())
+    }
+}
+
+/// TCP connection between a local and a remote socket.
 #[derive(Debug, From)]
 #[cdef]
 pub struct lb_tcpstream(#[opaque] TcpStream);
@@ -331,6 +499,7 @@ pub struct lb_tcpstream(#[opaque] TcpStream);
 #[metatype]
 impl lb_tcpstream {}

+/// TCP socket server, listening for connections.
 #[derive(Debug, From)]
 #[cdef]
 pub struct lb_tcplistener(#[opaque] TcpListener);
--- 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 +1,115 @@
-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 luaffi::{Module, Registry};
 use luajit::{Chunk, State};
-use std::fmt::Display;
+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>,
 }

 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}"),
+            }),
        }
-
-    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 module<T: Module>(&mut self) -> &mut Self {
+        self.registry.preload::<T>();
+        self
+    }
+
    pub fn build(&self) -> luajit::Result<Runtime> {
        Ok(Runtime {
+            cx: Context {
                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.eval(Chunk::new(self.registry.build()).path("[luby]"), 0, 0)?;
                    s
                },
+                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: self.state.new_thread(),
+            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 +1,107 @@
+//! # 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 luajit::{LUA_MULTRET, Type};
+use std::{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) in Lua.
+///
+/// ```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 / 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 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.
+        Self::__spawn(__ref(__tpack(f, variadic!())))
    }
-            println!("{s:?}");
+
+    extern "Lua-C" fn __spawn(key: c_int) -> lb_task {
+        let handle = spawn(async move |cx| {
+            // SAFETY: key is always unique, created by __ref above.
+            let arg = unsafe { cx.new_ref_unchecked(key) };
+            let mut s = cx.guard();
+            s.resize(0);
+            s.push(&arg);
+            let narg = s.unpack(1, 1, None) - 1; // unpack the function and its args from the table
+            debug_assert!(s.slot(2).type_of() == Type::Function);
+            match s.call_async(narg, LUA_MULTRET).await {
+                Ok(nret) => {
+                    s.pack(1, nret); // pack the return values back into the table
+                }
+                Err(err) => {
+                    drop(s);
+                    cx.report_error(&err);
+                }
+            }
+            let _ = arg.into_raw(); // the original ref is owned by the task handle and unref'ed there
        });

-        lb_task { handle }
+        lb_task {
+            handle: Some(handle),
+            __ref: key,
+        }
    }
 }

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

 #[metatype]
-impl lb_task {}
+impl lb_task {
+    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(&mut self) {
+        if let Some(handle) = self.handle.take() {
+            handle
+                .await
+                .unwrap_or_else(|err| panic!("task handler panicked: {err}"));
+        }
+    }
+
+    #[gc]
+    extern "Lua" fn gc(&self) {
+        __unref(self.__ref);
+    }
+}
--- 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 +1,17 @@
+local ok, net = pcall(require, "lb:net")
+if not ok then return 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)
+  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 +1,103 @@
+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("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("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)
+end)
+
+describe("sleep", function()
+  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)
+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 {
@@ -131,40 +170,6 @@ 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
@@ -1,3 +1,4 @@
+---@diagnostic disable
 local LUA_REFNIL = -1 -- lib_aux.c
 local FREELIST_REF = 0

--- a/crates/luaffi/src/lib.rs
+++ b/crates/luaffi/src/lib.rs
@@ -11,13 +11,14 @@ use std::{
    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
@@ -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"),
@@ -129,7 +129,7 @@ fn cache_local(f: &mut Formatter, list: &[(&str, &str)]) -> fmt::Result {
 #[derive(Debug, Clone, Default)]
 pub struct Registry {
    types: HashSet<String>,
-    funcs: HashSet<String>,
+    decls: HashSet<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 +451,16 @@ 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
 }

-impl<'r, 'm> MetatypeMethodBuilder<'r, 'm> {
+impl<'r, 'm> MetatypeFunctionBuilder<'r, 'm> {
    pub fn new(metatype: &'m mut MetatypeBuilder<'r>) -> Self {
        Self {
            metatype,
@@ -457,7 +479,7 @@ impl<'r, 'm> MetatypeMethodBuilder<'r, 'm> {
        );

        let Self {
-            metatype: MetatypeBuilder { registry, .. },
+            metatype: MetatypeBuilder { reg, .. },
            lparams,
            cparams,
            cargs,
@@ -466,7 +488,7 @@ impl<'r, 'm> MetatypeMethodBuilder<'r, 'm> {
            ..
        } = self;

-        registry.include::<T::From>();
+        reg.include::<T::From>();

        (!lparams.is_empty()).then(|| lparams.push_str(", "));
        (!cparams.is_empty()).then(|| cparams.push_str(", "));
@@ -517,12 +539,15 @@ impl<'r, 'm> MetatypeMethodBuilder<'r, 'm> {
        write!(prelude, "local __{name}_len = 0; if {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 +560,7 @@ 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 +569,7 @@ impl<'r, 'm> MetatypeMethodBuilder<'r, 'm> {
            ..
        } = self;

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

        match T::convention() {
@@ -587,6 +606,10 @@ 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 +643,7 @@ 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 +659,28 @@ 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;
@@ -756,11 +785,19 @@ 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 +805,59 @@ 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_ptr_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 {
+                "lightuserdata"
            }
        }
    };
 }

-impl_mut_ptr!(*mut T);
-impl_mut_ptr!(&mut T);
-impl_mut_ptr!(Option<&mut T>);
+impl_ptr_annotation!(*const T);
+impl_ptr_annotation!(*mut T);
+
+macro_rules! impl_ref_annotation {
+    ($ty:ty) => {
+        impl<T> Annotation for $ty
+        where
+            T: Annotation,
+        {
+            fn annotation() -> impl Display {
+                display!("{}", T::annotation())
+            }
+        }
+    };
+}
+
+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 +870,10 @@ 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 +895,10 @@ 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 {
@@ -857,7 +914,9 @@ 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>);

 //
@@ -880,7 +939,10 @@ impl_ptr_intoabi!(Option<&'static mut T>);
 //
 macro_rules! impl_ref_fromabi {
    ($ty:ty) => {
-        unsafe impl<'s, T: Type> FromFfi for $ty {
+        unsafe impl<'s, T> FromFfi for $ty
+        where
+            T: Type,
+        {
            type From = Option<$ty>;

            fn prelude(arg: &str) -> impl Display {
@@ -910,7 +972,10 @@ impl_ref_fromabi!(&'s mut T);
 //
 macro_rules! impl_ref_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 {
@@ -929,7 +994,10 @@ 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 +1011,23 @@ 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())
    }
@@ -961,18 +1041,27 @@ 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),*) -> $ret:tt) => {
+    ($ty:ident, fn($($arg:ident),*) -> $ret:ident) => {
        //
        // SAFETY: No `FromFfi` for function pointers because of borrow safety invariants (see above
        // in `&mut T`).
@@ -980,7 +1069,11 @@ macro_rules! impl_function {
        // We also can't implement `IntoFfi` because we can't call `FromFfi` and `IntoFfi` for the
        // function's respective argument and return values.
        //
-        unsafe impl<$($arg: Type,)* $ret: Type> Type for $ty<($($arg,)*), $ret> {
+        unsafe impl<$($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 +1087,8 @@ 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 +1097,40 @@ 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 str {
+    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
@@ -4,7 +4,7 @@ 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";
@@ -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)?)?;

-    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 })))
+            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;)* });
@@ -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
@@ -2,22 +2,26 @@ use crate::utils::{
    StringLike, ffi_crate, is_optionlike, is_primitivelike, 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)?;
@@ -54,6 +58,26 @@ fn generate_impls(imp: &mut ItemImpl) -> Result<TokenStream> {
    let mut mms = HashSet::new();
    let mut lua_drop = None;

+    // 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 get_ffi_functions(imp)? {
        if let Some(mm) = func.attrs.metamethod {
            syn_assert!(
@@ -66,6 +90,7 @@ fn generate_impls(imp: &mut ItemImpl) -> Result<TokenStream> {
        add_ffi_function(&mut registry, &func)?;
    }

+    // process extern "Lua" lua functions
    for func in get_lua_functions(imp)? {
        if let Some(mm) = func.attrs.metamethod {
            syn_assert!(
@@ -82,17 +107,19 @@ fn generate_impls(imp: &mut ItemImpl) -> Result<TokenStream> {
        }
    }

+    // 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 {
@@ -192,10 +219,10 @@ 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)]
@@ -224,30 +251,31 @@ 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,
@@ -258,15 +286,15 @@ 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));
-
+            func.sig.asyncness.is_some().then(|| document_async(func));
            document_ffi_function(func);

            funcs.push(FfiFunction {
                name: func.sig.ident.clone(),
-                is_async: func.sig.asyncness.is_some(),
                params,
                ret,
                attrs,
+                is_async: func.sig.asyncness.is_some(),
            });
        }
    }
@@ -279,7 +307,7 @@ 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(method) = Metamethod::try_from(&name.unraw())
        {
            match method {
                Metamethod::Gc => syn_error!(attr, "implement `Drop` instead"),
@@ -360,16 +388,8 @@ 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
@@ -380,99 +400,102 @@ fn add_ffi_function(registry: &mut Registry, func: &FfiFunction) -> Result<()> {
        ));
    }

-    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(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({
        let infer_args = iter::repeat_n(quote!(::std::unreachable!()), func_params.len());
@@ -481,23 +504,16 @@ fn add_ffi_function(registry: &mut Registry, func: &FfiFunction) -> Result<()> {
        } else {
            quote!(|| Self::#func_name(#(#infer_args),*))
        };
-        quote_spanned!(func_name.span() => b.call_inferred(#c_name, #infer);)
+        quote!(b.call_inferred(#c_name, #infer);)
    });

-    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(ref 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 +525,7 @@ 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]
@@ -546,27 +562,29 @@ 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 {
-                params.push(parse_quote_spanned!(variadic.span() => variadic!()));
+                params.push(parse_quote_spanned!(variadic.span() => variadic!())); // luaify builtin macro
            }

            let attrs = parse_lua_function_attrs(&mut func.attrs)?;
            attrs.metamethod.map(|mm| document_metamethod(func, mm));
-
+            func.sig.asyncness.is_some().then(|| document_async(func));
            document_lua_function(func);

            funcs.push(LuaFunction {
@@ -592,59 +610,43 @@ 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));
    }

-    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"),
-        }
+    for param in func.sig.inputs.iter() {
+        let ty = match param {
+            FnArg::Receiver(recv) => &recv.ty,
+            FnArg::Typed(ty) => &ty.ty,
        };

-    Ok(parse_quote!(#ffi::__internal::stub_types::#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 parse_lua_function_attrs(attrs: &mut Vec<Attribute>) -> Result<LuaFunctionAttrs> {
@@ -652,13 +654,8 @@ fn parse_lua_function_attrs(attrs: &mut Vec<Attribute>) -> Result<LuaFunctionAtt
    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(method) = Metamethod::try_from(&name.unraw())
        {
-            match method {
-                Metamethod::New => syn_error!(attr, r#"cannot be applied to a lua function"#),
-                _ => {}
-            }
-
            parsed.metamethod = Some(method);
            attrs.remove(i);
        } else {
@@ -678,12 +675,8 @@ 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(ref mm) => quote!(b.metatable_raw(#mm, #luaify(|#(#params),*| #body));),
+        None => quote!(b.index_raw(#name, #luaify(|#(#params),*| #body));),
    });

    Ok(())
@@ -718,40 +711,36 @@ fn inject_merged_drop(registry: &mut Registry, lua: Option<&LuaFunction>) -> Res
            "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) }
@@ -763,42 +752,73 @@ fn inject_merged_drop(registry: &mut Registry, lua: Option<&LuaFunction>) -> Res

 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>"#
+        r#"<span
+            class="stab"
+            title="This function is implemented in Rust and called via FFI."
+            style="float: right; background: #fff5d6; font-weight: 500; margin-left: 3px; padding-left: 5px; padding-right: 5px;"
+        >FFI</span>"#
    ]));
 }

 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>"#
+        r#"<span
+            class="stab"
+            title="This function is implemented in Lua."
+            style="float: right; background: #ebf5ff; font-weight: 500; margin-left: 3px; padding-left: 5px; padding-right: 5px;"
+        >Lua</span>"#
+    ]));
+}
+
+fn document_async(func: &mut ImplItemFn) {
+    func.attrs.insert(0, parse_quote!(#[doc =
+        r#"<span
+            class="stab"
+            title="This function is asynchronous and will yield the calling thread."
+            style="float: right; background: #ebf5ff; margin-left: 3px; padding-left: 5px; padding-right: 5px;"
+        >Async</span>"#
    ]));
 }

 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(),
+    func.attrs.insert(0, parse_quote!(#[doc =
+        r#"<span
+            class="stab"
+            title="This function is a metamethod."
+            style="float: right; background: #ebf5ff; margin-left: 3px; padding-left: 5px; padding-right: 5px;"
+        >Metamethod</span>"#
+    ]));
+
+    let doc = match method {
+        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]));
+    func.attrs.push(parse_quote!(#[doc = "# Metamethod"]));
+    func.attrs.push(parse_quote!(#[doc = ""]));
+    func.attrs.push(parse_quote!(#[doc = #doc]));
 }
--- 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
--- 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 +1,7 @@
-use crate::{generate::generate, transform::transform};
+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 +19,13 @@ 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/src/lib.rs
+++ b/crates/luajit/src/lib.rs
@@ -9,6 +9,7 @@ use std::{
    ffi::{CStr, CString, NulError},
    fmt,
    marker::PhantomData,
+    mem::ManuallyDrop,
    ops::{Deref, DerefMut},
    os::raw::{c_char, c_int, c_void},
    pin::Pin,
@@ -35,6 +36,11 @@ pub fn url() -> &'static str {
    LUAJIT_URL.to_str().unwrap()
 }

+// reexport constants
+pub use luajit_sys::{
+    LUA_ENVIRONINDEX, LUA_GLOBALSINDEX, LUA_MULTRET, LUA_NOREF, LUA_REFNIL, LUA_REGISTRYINDEX,
+};
+
 /// Lua error.
 #[derive(Debug, Error)]
 #[non_exhaustive]
@@ -477,6 +483,19 @@ pub struct Ref {
    key: c_int,
 }

+impl Ref {
+    /// Consumes this ref and returns the original key used to create the ref.
+    ///
+    /// This key can be used to index into the registry table ([`LUA_REGISTRYINDEX`]) to retrieve
+    /// the referenced value. The key can be converted back into a ref using
+    /// [`State::new_ref_unchecked`].
+    pub fn into_raw(self) -> c_int {
+        let Self { ref mut state, key } = *ManuallyDrop::new(self);
+        unsafe { ptr::drop_in_place(state) }
+        key
+    }
+}
+
 impl Drop for Ref {
    fn drop(&mut self) {
        // SAFETY: luaL_unref is guaranteed to not fail
@@ -871,7 +890,7 @@ impl Stack {
    /// array-part, these values are **not** cleared. The number of values popped is returned, which
    /// is always equal to `n`.
    ///
-    /// This method does not invoke any metamethods.
+    /// This method does not invoke any metamethods. The table is not popped from the stack.
    ///
    /// Equivalent to `table.pack(...)`.
    ///
@@ -907,7 +926,8 @@ impl Stack {
    /// pushed at the top of the stack in ascending order. If `i > j`, then nothing is pushed.
    /// Otherwise, `j - i + 1` values are pushed, and the number of values pushed is returned.
    ///
-    /// This method does not invoke any metamethods.
+    /// This method does not invoke any metamethods. The table is not popped from the stack or
+    /// altered in any way.
    ///
    /// Equivalent to `table.unpack(list, i, j)`.
    ///
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,2 +1,20 @@
+#[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;
+
+#[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 = "fs")]
+    rt.module::<fs::lb_fslib>();
+    #[cfg(feature = "net")]
+    rt.module::<net::lb_netlib>();
+}
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,7 +1,7 @@
 use clap::Parser;
 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 +20,42 @@ 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.
@@ -80,10 +98,12 @@ struct Args {
    blocking_threads: NonZero<usize>,

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

    /// tokio-console publish address.
+    #[cfg(feature = "tokio-console")]
    #[clap(
        long,
        help_heading = "Debugging",
@@ -91,7 +111,16 @@ 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 +137,13 @@ 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 +154,10 @@ 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 +175,7 @@ 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 +189,75 @@ 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).build().unwrap()
+    };

    for arg in args.jit.iter() {
        let mut s = rt.guard();
-        if let Some((cmd, flags)) = parse_jitlib_cmd(arg)
+        let res = if let Some((cmd, flags)) = parse_jitlib_cmd(arg)
            && let Ok(_) = s.require(format!("jit.{cmd}"), 1)
        {
            (s.push("start"), s.get(-2), s.push(flags));
-            s.call(1, 0)
+            s.call(1, 0) // require("jit.{cmd}").start(flags)
        } else {
            s.require("jit", 1).unwrap();
            match arg.as_str() {
                cmd @ ("on" | "off" | "flush") => {
                    (s.push(cmd), s.get(-2));
-                    s.call(0, 0)
+                    s.call(0, 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, 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 +265,29 @@ 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(&luajit::Chunk::new(chunk).path(path)) {
+            cx.report_error(err);
+        } else if let Err(ref err) = cx.call_async(0, 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 +1,125 @@
+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 module") end
+local ok, fs = pcall(require, "lb:fs")
+if not ok then error("lua test harness requires lb:fs module") end
+
+local global = _G
+local colors = {
+  reset = "\x1b[0m",
+  pass = "\x1b[32;1m",
+  fail = "\x1b[31;1m",
+}
+
+local icons = {
+  check = "\u{2713}",
+  cross = "\u{00d7}",
+  chevron = "\u{203a}",
+}
+
+local function color(name, s)
+  return colors[name] .. s .. colors.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 })
+  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 })
+
+  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 = string.format("%s %s %s", group.name, icons.chevron, name) end
+    group = group.parent
+  end
+  return name
+end
+
+local function trace(msg)
+  return color("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("", string.format("%s %s", color("pass", "PASS"), name_test(test)))
+  else
+    test.state = "fail"
+    print("", string.format("%s %s\n\n%s\n", color("fail", "FAIL"), name_test(test), res))
+  end
+  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 main(item)
+  local cx = { tasks = {} }
+  local pass, fail = 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
+  if fail == 0 then
+    print("", color("pass", string.format("%s %d tests passed", icons.check, pass)))
+    return 0
+  end
+  print(
+    "",
+    color("pass", string.format("%s %d tests passed", icons.check, pass))
+      .. ", "
+      .. color("fail", string.format("%s %d tests failed", icons.cross, fail))
+  )
+  return 1 -- 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 +1,47 @@
+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).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()).path(path)) {
+            s.report_error(err);
+        } else if let Err(ref err) = s.call_async(0, 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	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