✨ feat: add mlua integration

examples/mlua/.cargo/config

@@ -0,0 +1,11 @@
+[target.x86_64-apple-darwin]
+rustflags = [
+  "-C", "link-arg=-undefined",
+  "-C", "link-arg=dynamic_lookup",
+]
+
+[target.aarch64-apple-darwin]
+rustflags = [
+  "-C", "link-arg=-undefined",
+  "-C", "link-arg=dynamic_lookup",
+]

examples/mlua/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "lua"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+nvim-oxi = { path = "../../nvim-oxi", features = ["mlua"] }
+mlua = { version = "0.8", features = ["luajit"] }

examples/mlua/README.md

@@ -0,0 +1,4 @@
+# mlua
+
+`require("lua").greetings()` will print `"Hello from Rust.."` followed by
+`"..and goodbye from Lua!"`.

examples/mlua/src/lib.rs

@@ -0,0 +1,17 @@
+use mlua::prelude::LuaFunction;
+use nvim_oxi::{self as oxi, Dictionary, Function};
+
+fn greetings(_: ()) -> oxi::Result<()> {
+    oxi::print!("Hello from Rust..");
+
+    let lua = oxi::mlua::lua();
+    let print = lua.globals().get::<_, LuaFunction>("print")?;
+    print.call("..and goodbye from Lua!")?;
+
+    Ok(())
+}
+
+#[oxi::module]
+fn lua() -> oxi::Result<Dictionary> {
+    Ok(Dictionary::from_iter([("greetings", Function::from_fn(greetings))]))
+}

flake.nix

@@ -41,9 +41,11 @@
             buildInputs = lib.lists.optionals stdenv.isDarwin [ pkgs.libiconv ];
 
             packages = with pkgs; [
-              gcc
               (rust-bin.selectLatestNightlyWith (toolchain: toolchain.default))
+              gcc
+              luajit
               neovim
+              pkg-config
             ];
           }
         );

nvim-oxi/Cargo.toml

@@ -18,6 +18,7 @@ rustdoc-args = ["--cfg", "docsrs"]
 [features]
 libuv-rs = ["loop", "dep:libuv"]
 loop = ["dep:libuv-sys2"]
+mlua = ["dep:mlua"]
 nightly = []
 test = ["dep:oxi-test"]
 
@@ -26,6 +27,7 @@ derive_builder = "0.11"
 libc = "0.2"
 libuv-sys2 = { version = "1.43", optional = true }
 libuv = { version = "2.4", optional = true }
+mlua = { version = "0.8", optional = true }
 nvim-types = { version = "0.1", path = "../nvim-types", features = ["serde"] }
 once_cell = "1.12"
 oxi-module = { version = "0.1", path = "../oxi-module" }

nvim-oxi/src/error.rs

@@ -6,7 +6,8 @@ use serde::{de, ser};
 pub type Result<T> = std::result::Result<T, Error>;
 
 /// Error returned by `nvim-oxi` functions.
-#[derive(thiserror::Error, Debug, Eq, PartialEq)]
+#[derive(thiserror::Error, Debug)]
+#[cfg_attr(not(feature = "mlua"), derive(Eq, PartialEq))]
 pub enum Error {
     #[error(transparent)]
     NvimError(#[from] nvim_types::Error),
@@ -40,6 +41,10 @@ pub enum Error {
 
     #[error("{0}")]
     Other(String),
+
+    #[cfg(feature = "mlua")]
+    #[error(transparent)]
+    MluaError(#[from] mlua::Error),
 }
 
 impl ser::Error for Error {

nvim-oxi/src/lib.rs

@@ -42,6 +42,19 @@ pub mod types {
 #[cfg_attr(docsrs, doc(cfg(feature = "loop")))]
 pub mod libuv;
 
+#[cfg(feature = "mlua")]
+#[cfg_attr(docsrs, doc(cfg(feature = "mlua")))]
+pub mod mlua {
+    /// Returns a static reference to a
+    /// [`mlua::Lua`](https://docs.rs/mlua/latest/mlua/struct.Lua.html) object
+    /// to be able to interact with other Lua plugins.
+    pub fn lua() -> &'static mlua::Lua {
+        crate::lua::with_state(|lstate| unsafe {
+            mlua::Lua::init_from_ptr(lstate as *mut _).into_static()
+        })
+    }
+}
+
 // Re-exports.
 pub use error::{Error, Result};
 pub use lua::Function;

nvim-oxi/src/toplevel.rs

@@ -48,7 +48,6 @@ macro_rules! dbg {
     };
 }
 
-
 /// Prints a message to the Neovim message area.
 #[doc(hidden)]
 pub fn __print(text: impl Into<String>) {