update rust crates to 2024 edition

lua-playground/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "lua-playground"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 
 [lib]
 crate-type = ["cdylib"]

lua-playground/build.rs

@@ -2,7 +2,7 @@ use std::env;
 use std::path::PathBuf;
 
 fn main() {
-    let book_output_path = env::var("BOOK_OUTPUT_PATH").map_or(None, Some);
+    let book_output_path = env::var("BOOK_OUTPUT_PATH").ok();
 
     let out_dir = env::var("OUT_DIR").unwrap();
     let pkg_name = env::var("CARGO_PKG_NAME").unwrap();
@@ -19,5 +19,12 @@ fn main() {
     println!("cargo:rustc-link-arg=-sEXPORT_ES6=1");
     println!("cargo:rustc-link-arg=-sERROR_ON_UNDEFINED_SYMBOLS=0");
     println!("cargo:rustc-link-arg=--no-entry");
-    println!("cargo:rustc-link-arg=-o{}.js", book_output_path.map(PathBuf::from).unwrap_or(target_path).join(pkg_name).to_string_lossy());
+    println!(
+        "cargo:rustc-link-arg=-o{}.js",
+        book_output_path
+            .map(PathBuf::from)
+            .unwrap_or(target_path)
+            .join(pkg_name)
+            .to_string_lossy()
+    );
 }

lua-playground/src/lib.rs

@@ -1,18 +1,20 @@
-use std::ffi::{c_char, CStr};
-use mlua::Lua;
+#![allow(clippy::missing_safety_doc)]
 
-#[no_mangle]
-pub extern "C" fn lua_new() -> *mut Lua {
+use mlua::Lua;
+use std::ffi::{CStr, c_char};
+
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn lua_new() -> *mut Lua {
     let lua = Lua::new();
     Box::into_raw(Box::new(lua))
 }
 
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub unsafe extern "C" fn lua_execute(lua: *mut Lua, to_execute: *const c_char) {
-    let lua: &mut Lua = &mut *lua;
-    let to_execute = CStr::from_ptr(to_execute);
+    let lua: &mut Lua = unsafe { &mut *lua };
+    let to_execute = unsafe { CStr::from_ptr(to_execute) };
 
-    if let Err(err) = lua.load(&to_execute.to_string_lossy().to_string()).exec() {
+    if let Err(err) = lua.load(to_execute.to_string_lossy().to_string()).exec() {
         eprintln!("{}", err)
     }
 }