rhai/codegen/src/lib.rs
2020-09-17 20:27:45 -05:00

197 lines
6.3 KiB
Rust

//!
//! This crate contains procedural macros to make creating Rhai modules much easier.
//!
//! # Exporting a Macro to Rhai
//!
//! ```
//! use rhai::{EvalAltResult, FLOAT};
//! use rhai::plugin::*;
//! use rhai::module_resolvers::*;
//!
//! #[rhai::export_module]
//! pub mod advanced_math {
//! use rhai::FLOAT;
//!
//! pub const MYSTIC_NUMBER: FLOAT = 42.0 as FLOAT;
//!
//! pub fn euclidean_distance(x1: FLOAT, y1: FLOAT, x2: FLOAT, y2: FLOAT) -> FLOAT {
//! ((y2 - y1).abs().powf(2.0) + (x2 -x1).abs().powf(2.0)).sqrt()
//! }
//! }
//!
//! fn main() -> Result<(), Box<EvalAltResult>> {
//! let mut engine = Engine::new();
//! let m = rhai::exported_module!(advanced_math);
//! let mut r = StaticModuleResolver::new();
//! r.insert("Math::Advanced".to_string(), m);
//! engine.set_module_resolver(Some(r));
//!
//! assert_eq!(engine.eval::<FLOAT>(
//! r#"import "Math::Advanced" as math;
//! let m = math::MYSTIC_NUMBER;
//! let x = math::euclidean_distance(0.0, 1.0, 0.0, m);
//! x"#)?, 41.0);
//! Ok(())
//! }
//! ```
//!
//! # Exporting a Function to a Rhai Module
//!
//! ```
//! use rhai::{EvalAltResult, FLOAT, Module, RegisterFn};
//! use rhai::plugin::*;
//! use rhai::module_resolvers::*;
//!
//! #[rhai::export_fn]
//! pub fn distance_function(x1: FLOAT, y1: FLOAT, x2: FLOAT, y2: FLOAT) -> FLOAT {
//! ((y2 - y1).abs().powf(2.0) + (x2 -x1).abs().powf(2.0)).sqrt()
//! }
//!
//! fn main() -> Result<(), Box<EvalAltResult>> {
//!
//! let mut engine = Engine::new();
//! engine.register_fn("get_mystic_number", || { 42 as FLOAT });
//! let mut m = Module::new();
//! rhai::set_exported_fn!(m, "euclidean_distance", distance_function);
//! let mut r = StaticModuleResolver::new();
//! r.insert("Math::Advanced".to_string(), m);
//! engine.set_module_resolver(Some(r));
//!
//! assert_eq!(engine.eval::<FLOAT>(
//! r#"import "Math::Advanced" as math;
//! let m = get_mystic_number();
//! let x = math::euclidean_distance(0.0, 1.0, 0.0, m);
//! x"#)?, 41.0);
//! Ok(())
//! }
//! ```
//!
//! # Exporting a Function to an Engine
//!
//! ```
//! use rhai::{EvalAltResult, FLOAT, Module, RegisterFn};
//! use rhai::plugin::*;
//! use rhai::module_resolvers::*;
//!
//! #[rhai::export_fn]
//! pub fn distance_function(x1: FLOAT, y1: FLOAT, x2: FLOAT, y2: FLOAT) -> FLOAT {
//! ((y2 - y1).abs().powf(2.0) + (x2 -x1).abs().powf(2.0)).sqrt()
//! }
//!
//! fn main() -> Result<(), Box<EvalAltResult>> {
//!
//! let mut engine = Engine::new();
//! engine.register_fn("get_mystic_number", || { 42 as FLOAT });
//! rhai::register_exported_fn!(engine, "euclidean_distance", distance_function);
//!
//! assert_eq!(engine.eval::<FLOAT>(
//! r#"let m = get_mystic_number();
//! let x = euclidean_distance(0.0, 1.0, 0.0, m);
//! x"#)?, 41.0);
//! Ok(())
//! }
//! ```
//!
use quote::quote;
use syn::parse_macro_input;
mod attrs;
mod function;
mod module;
mod register;
mod rhai_module;
#[cfg(test)]
mod test;
#[proc_macro_attribute]
pub fn export_fn(
args: proc_macro::TokenStream,
input: proc_macro::TokenStream,
) -> proc_macro::TokenStream {
let mut output = proc_macro2::TokenStream::from(input.clone());
let parsed_params = match crate::attrs::outer_item_attributes(args.into(), "export_fn") {
Ok(args) => args,
Err(err) => return proc_macro::TokenStream::from(err.to_compile_error()),
};
let mut function_def = parse_macro_input!(input as function::ExportedFn);
if let Err(e) = function_def.set_params(parsed_params) {
return e.to_compile_error().into();
}
output.extend(function_def.generate());
proc_macro::TokenStream::from(output)
}
#[proc_macro_attribute]
pub fn export_module(
args: proc_macro::TokenStream,
input: proc_macro::TokenStream,
) -> proc_macro::TokenStream {
let parsed_params = match crate::attrs::outer_item_attributes(args.into(), "export_module") {
Ok(args) => args,
Err(err) => return proc_macro::TokenStream::from(err.to_compile_error()),
};
let mut module_def = parse_macro_input!(input as module::Module);
if let Err(e) = module_def.set_params(parsed_params) {
return e.to_compile_error().into();
}
let tokens = module_def.generate();
proc_macro::TokenStream::from(tokens)
}
#[proc_macro]
pub fn exported_module(module_path: proc_macro::TokenStream) -> proc_macro::TokenStream {
let module_path = parse_macro_input!(module_path as syn::Path);
let tokens = quote::quote! {
#module_path::rhai_module_generate()
};
proc_macro::TokenStream::from(tokens)
}
#[proc_macro]
pub fn combine_with_exported_module(args: proc_macro::TokenStream) -> proc_macro::TokenStream {
let (module_expr, _export_name, module_path) = match crate::register::parse_register_macro(args)
{
Ok(triple) => triple,
Err(e) => return e.to_compile_error().into(),
};
let tokens = quote! {
#module_path::rhai_generate_into_module(#module_expr, true);
};
proc_macro::TokenStream::from(tokens)
}
#[proc_macro]
pub fn register_exported_fn(args: proc_macro::TokenStream) -> proc_macro::TokenStream {
let (engine_expr, export_name, rust_modpath) = match crate::register::parse_register_macro(args)
{
Ok(triple) => triple,
Err(e) => return e.to_compile_error().into(),
};
let gen_mod_path = crate::register::generated_module_path(&rust_modpath);
let tokens = quote! {
#engine_expr.register_result_fn(&(#export_name), #gen_mod_path::dynamic_result_fn);
};
proc_macro::TokenStream::from(tokens)
}
#[proc_macro]
pub fn set_exported_fn(args: proc_macro::TokenStream) -> proc_macro::TokenStream {
let (module_expr, export_name, rust_modpath) = match crate::register::parse_register_macro(args)
{
Ok(triple) => triple,
Err(e) => return e.to_compile_error().into(),
};
let gen_mod_path = crate::register::generated_module_path(&rust_modpath);
let tokens = quote! {
#module_expr.set_fn(#export_name, FnAccess::Public,
#gen_mod_path::token_input_types().as_ref(),
#gen_mod_path::token_callable());
};
proc_macro::TokenStream::from(tokens)
}