Add basic fs lib

crates/lb/src/fs.rs

@@ -0,0 +1,32 @@
+//! The `lb:fs` module provides utilities for interacting with the file system asynchronously.
+//!
+//! See [`lb_libfs`] for items exported by this module.
+use luaffi::{cdef, metatype};
+use std::io;
+use tokio::fs;
+
+/// Items exported by the `lb:fs` module.
+///
+/// This module can be obtained by calling `require` in Lua.
+///
+/// ```lua
+/// local fs = require("lb:fs");
+/// ```
+#[cdef]
+pub struct lb_libfs;
+
+#[metatype]
+impl lb_libfs {
+    #[new]
+    extern "Lua-C" fn new() -> Self {
+        Self
+    }
+
+    pub extern "Lua" fn read(&self, path: string) -> string {
+        self.__read(path)
+    }
+
+    async extern "Lua-C" fn __read(&self, path: &str) -> io::Result<Vec<u8>> {
+        fs::read(path).await
+    }
+}