Split register export macro, add Engine support

codegen/src/function.rs

@@ -229,8 +229,10 @@ impl ExportedFn {
         }
     }
 
-    pub fn generate_with_params(mut self,
+    pub fn generate_with_params(
-                                mut params: ExportedFnParams) -> proc_macro2::TokenStream {
+        mut self,
+        mut params: ExportedFnParams,
+    ) -> proc_macro2::TokenStream {
         self.params = params;
         self.generate()
     }
@@ -241,11 +243,12 @@ impl ExportedFn {
         } else {
             self.name().to_string()
         };
-        let name: syn::Ident = syn::Ident::new(&format!("rhai_fn_{}", name_str),
+        let name: syn::Ident =
-                                               self.name().span());
+            syn::Ident::new(&format!("rhai_fn_{}", name_str), self.name().span());
         let impl_block = self.generate_impl("Token");
         let callable_block = self.generate_callable("Token");
         let input_types_block = self.generate_input_types("Token");
+        let dyn_result_fn_block = self.generate_dynamic_fn();
         quote! {
             #[allow(unused)]
             pub mod #name {
@@ -254,6 +257,54 @@ impl ExportedFn {
                 #impl_block
                 #callable_block
                 #input_types_block
+                #dyn_result_fn_block
+            }
+        }
+    }
+
+    pub fn generate_dynamic_fn(&self) -> proc_macro2::TokenStream {
+        let name: syn::Ident = if let Some(ref name) = self.params.name {
+            syn::Ident::new(name, self.name().span())
+        } else {
+            self.name().clone()
+        };
+
+        let mut dynamic_signature = self.signature.clone();
+        dynamic_signature.ident =
+            syn::Ident::new("dynamic_result_fn", proc_macro2::Span::call_site());
+        dynamic_signature.output = syn::parse2::<syn::ReturnType>(quote! {
+            -> Result<Dynamic, EvalBox>
+        })
+        .unwrap();
+        let arguments: Vec<syn::Ident> = dynamic_signature
+            .inputs
+            .iter()
+            .filter_map(|fnarg| {
+                if let syn::FnArg::Typed(syn::PatType { ref pat, .. }) = fnarg {
+                    if let syn::Pat::Ident(ref ident) = pat.as_ref() {
+                        Some(ident.ident.clone())
+                    } else {
+                        None
+                    }
+                } else {
+                    None
+                }
+            })
+            .collect();
+
+        if !self.params.return_raw {
+            quote! {
+                type EvalBox = Box<EvalAltResult>;
+                pub #dynamic_signature {
+                    Ok(Dynamic::from(super::#name(#(#arguments),*)))
+                }
+            }
+        } else {
+            quote! {
+                type EvalBox = Box<EvalAltResult>;
+                pub #dynamic_signature {
+                    super::#name(#(#arguments),*)
+                }
             }
         }
     }
@@ -740,6 +791,10 @@ mod generate_tests {
                 pub fn token_input_types() -> Box<[std::any::TypeId]> {
                     Token().input_types()
                 }
+                type EvalBox = Box<EvalAltResult>;
+                pub fn dynamic_result_fn() -> Result<Dynamic, EvalBox> {
+                    Ok(Dynamic::from(super::do_nothing()))
+                }
             }
         };
 
@@ -784,6 +839,10 @@ mod generate_tests {
                 pub fn token_input_types() -> Box<[std::any::TypeId]> {
                     Token().input_types()
                 }
+                type EvalBox = Box<EvalAltResult>;
+                pub fn dynamic_result_fn(x: usize) -> Result<Dynamic, EvalBox> {
+                    Ok(Dynamic::from(super::do_something(x)))
+                }
             }
         };
 
@@ -863,6 +922,10 @@ mod generate_tests {
                 pub fn token_input_types() -> Box<[std::any::TypeId]> {
                     Token().input_types()
                 }
+                type EvalBox = Box<EvalAltResult>;
+                pub fn dynamic_result_fn(x: usize, y: usize) -> Result<Dynamic, EvalBox> {
+                    Ok(Dynamic::from(super::add_together(x, y)))
+                }
             }
         };
 
@@ -909,6 +972,10 @@ mod generate_tests {
                 pub fn token_input_types() -> Box<[std::any::TypeId]> {
                     Token().input_types()
                 }
+                type EvalBox = Box<EvalAltResult>;
+                pub fn dynamic_result_fn(x: &mut usize, y: usize) -> Result<Dynamic, EvalBox> {
+                    Ok(Dynamic::from(super::increment(x, y)))
+                }
             }
         };
 
@@ -954,6 +1021,10 @@ mod generate_tests {
                 pub fn token_input_types() -> Box<[std::any::TypeId]> {
                     Token().input_types()
                 }
+                type EvalBox = Box<EvalAltResult>;
+                pub fn dynamic_result_fn(message: &str) -> Result<Dynamic, EvalBox> {
+                    Ok(Dynamic::from(super::special_print(message)))
+                }
             }
         };
 

codegen/src/lib.rs

@@ -35,7 +35,7 @@
 //! }
 //! ```
 //!
-//! # Exporting a Function to Rhai
+//! # Exporting a Function to a Rhai Module
 //!
 //! ```
 //! use rhai::{EvalAltResult, FLOAT, Module, RegisterFn};
@@ -52,7 +52,7 @@
 //!     let mut engine = Engine::new();
 //!     engine.register_fn("get_mystic_number", || { 42 as FLOAT });
 //!     let mut m = Module::new();
-//!     rhai::register_exported_fn!(m, "euclidean_distance", distance_function);
+//!     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));
@@ -66,12 +66,39 @@
 //! }
 //! ```
 //!
+//! # 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, quote_spanned, ToTokens};
+use quote::{quote, ToTokens};
-use syn::{parse::Parser, parse_macro_input, spanned::Spanned};
+use syn::parse_macro_input;
 
 mod function;
 mod module;
+mod register;
 mod rhai_module;
 
 #[proc_macro_attribute]
@@ -118,47 +145,30 @@ pub fn exported_module(module_path: proc_macro::TokenStream) -> proc_macro::Toke
 
 #[proc_macro]
 pub fn register_exported_fn(args: proc_macro::TokenStream) -> proc_macro::TokenStream {
-    let parser = syn::punctuated::Punctuated::<syn::Expr, syn::Token![,]>::parse_separated_nonempty;
+    let (engine_expr, export_name, rust_modpath) = match crate::register::parse_register_macro(args)
-    let args = parser.parse(args).unwrap();
+    {
-    let arg_span = args.span();
+        Ok(triple) => triple,
-    let items: Vec<syn::Expr> = args.into_iter().collect();
+        Err(e) => return e.to_compile_error().into(),
-    if items.len() != 3 {
-        return proc_macro::TokenStream::from(
-            syn::Error::new(arg_span, "this macro requires three arguments").to_compile_error(),
-        );
-    }
-    let rhai_module = &items[0];
-    let export_name = match &items[1] {
-        syn::Expr::Lit(litstr) => quote_spanned!(items[1].span()=>
-                                                 #litstr.to_string()),
-        expr => quote! { #expr },
-    };
-    let rust_modpath = if let syn::Expr::Path(ref path) = &items[2] {
-        &path.path
-    } else {
-        return proc_macro::TokenStream::from(
-            syn::Error::new(items[2].span(), "third argument must be a function name")
-                .to_compile_error(),
-        );
-    };
-    let gen_mod_path: syn::punctuated::Punctuated<syn::PathSegment, _> = {
-        let mut g = rust_modpath.clone().segments;
-        g.pop();
-        let ident = syn::Ident::new(
-            &format!("rhai_fn_{}", rust_modpath.segments.last().unwrap().ident),
-            items[2].span(),
-        );
-        g.push_value(syn::PathSegment {
-            ident,
-            arguments: syn::PathArguments::None,
-        });
-        g
     };
+    let gen_mod_path = crate::register::generated_module_path(&rust_modpath);
     let tokens = quote! {
-        #rhai_module.set_fn(#export_name, rhai::FnAccess::Public,
+        #engine_expr.register_result_fn(&(#export_name), #gen_mod_path::dynamic_result_fn);
-                            #gen_mod_path::token_input_types().as_ref(),
+    };
-                            #gen_mod_path::token_callable());
+    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, rhai::FnAccess::Public,
+                            #gen_mod_path::token_input_types().as_ref(),
+                            #gen_mod_path::token_callable());
     };
     proc_macro::TokenStream::from(tokens)
 }

codegen/src/register.rs

@@ -0,0 +1,49 @@
+use quote::{quote, quote_spanned};
+use syn::{parse::Parser, spanned::Spanned};
+
+pub(crate) fn generated_module_path(
+    fn_path: &syn::Path,
+) -> syn::punctuated::Punctuated<syn::PathSegment, syn::Token![::]> {
+    let mut g = fn_path.clone().segments;
+    g.pop();
+    let ident = syn::Ident::new(
+        &format!("rhai_fn_{}", fn_path.segments.last().unwrap().ident),
+        fn_path.span(),
+    );
+    g.push_value(syn::PathSegment {
+        ident,
+        arguments: syn::PathArguments::None,
+    });
+    g
+}
+
+type RegisterMacroInput = (syn::Expr, proc_macro2::TokenStream, syn::Path);
+pub fn parse_register_macro(
+    args: proc_macro::TokenStream,
+) -> Result<RegisterMacroInput, syn::Error> {
+    let parser = syn::punctuated::Punctuated::<syn::Expr, syn::Token![,]>::parse_separated_nonempty;
+    let args = parser.parse(args).unwrap();
+    let arg_span = args.span();
+    let mut items: Vec<syn::Expr> = args.into_iter().collect();
+    if items.len() != 3 {
+        return Err(syn::Error::new(
+            arg_span,
+            "this macro requires three arguments",
+        ));
+    }
+    let export_name = match &items[1] {
+        syn::Expr::Lit(litstr) => quote_spanned!(items[1].span()=>
+                                                 #litstr.to_string()),
+        expr => quote! { #expr },
+    };
+    let rust_modpath = if let syn::Expr::Path(ref path) = &items[2] {
+        path.path.clone()
+    } else {
+        return Err(syn::Error::new(
+            items[2].span(),
+            "third argument must be a function name",
+        ));
+    };
+    let module = items.remove(0);
+    Ok((module, export_name, rust_modpath))
+}

codegen/tests/test_functions.rs

@@ -16,7 +16,7 @@ fn raw_fn_test() -> Result<(), Box<EvalAltResult>> {
     let mut engine = Engine::new();
     engine.register_fn("get_mystic_number", || 42 as FLOAT);
     let mut m = Module::new();
-    rhai::register_exported_fn!(
+    rhai::set_exported_fn!(
         m,
         "euclidean_distance".to_string(),
         raw_fn::distance_function
@@ -50,7 +50,7 @@ fn raw_fn_mut_test() -> Result<(), Box<EvalAltResult>> {
     let mut engine = Engine::new();
     engine.register_fn("get_mystic_number", || 42 as FLOAT);
     let mut m = Module::new();
-    rhai::register_exported_fn!(m, "add_in_place", raw_fn_mut::add_in_place);
+    rhai::set_exported_fn!(m, "add_in_place", raw_fn_mut::add_in_place);
     let mut r = StaticModuleResolver::new();
     r.insert("Math::Advanced".to_string(), m);
     engine.set_module_resolver(Some(r));
@@ -82,7 +82,7 @@ fn raw_fn_str_test() -> Result<(), Box<EvalAltResult>> {
     let mut engine = Engine::new();
     engine.register_fn("get_mystic_number", || 42 as FLOAT);
     let mut m = Module::new();
-    rhai::register_exported_fn!(m, "write_out_str", raw_fn_str::write_out_str);
+    rhai::set_exported_fn!(m, "write_out_str", raw_fn_str::write_out_str);
     let mut r = StaticModuleResolver::new();
     r.insert("Host::IO".to_string(), m);
     engine.set_module_resolver(Some(r));
@@ -138,9 +138,9 @@ mod mut_opaque_ref {
 fn mut_opaque_ref_test() -> Result<(), Box<EvalAltResult>> {
     let mut engine = Engine::new();
     let mut m = Module::new();
-    rhai::register_exported_fn!(m, "new_message", mut_opaque_ref::new_message);
+    rhai::set_exported_fn!(m, "new_message", mut_opaque_ref::new_message);
-    rhai::register_exported_fn!(m, "new_os_message", mut_opaque_ref::new_os_message);
+    rhai::set_exported_fn!(m, "new_os_message", mut_opaque_ref::new_os_message);
-    rhai::register_exported_fn!(m, "write_out_message", mut_opaque_ref::write_out_message);
+    rhai::set_exported_fn!(m, "write_out_message", mut_opaque_ref::write_out_message);
     let mut r = StaticModuleResolver::new();
     r.insert("Host::Msg".to_string(), m);
     engine.set_module_resolver(Some(r));
@@ -174,7 +174,7 @@ fn rename_fn_test() -> Result<(), Box<EvalAltResult>> {
     let mut engine = Engine::new();
     engine.register_fn("get_mystic_number", || 42 as FLOAT);
     let mut m = Module::new();
-    rhai::register_exported_fn!(m, "add_two_floats", rename_fn::add_float);
+    rhai::set_exported_fn!(m, "add_two_floats", rename_fn::add_float);
     let mut r = StaticModuleResolver::new();
     r.insert("Math::Advanced".to_string(), m);
     engine.set_module_resolver(Some(r));
@@ -211,8 +211,8 @@ fn duplicate_fn_rename_test() -> Result<(), Box<EvalAltResult>> {
     let mut engine = Engine::new();
     engine.register_fn("get_mystic_number", || 42 as FLOAT);
     let mut m = Module::new();
-    rhai::register_exported_fn!(m, "add_two_floats", duplicate_fn_rename::add_float);
+    rhai::set_exported_fn!(m, "add_two_floats", duplicate_fn_rename::add_float);
-    rhai::register_exported_fn!(m, "add_two_ints", duplicate_fn_rename::add_int);
+    rhai::set_exported_fn!(m, "add_two_ints", duplicate_fn_rename::add_int);
     let mut r = StaticModuleResolver::new();
     r.insert("Math::Advanced".to_string(), m);
     engine.set_module_resolver(Some(r));
@@ -224,7 +224,7 @@ fn duplicate_fn_rename_test() -> Result<(), Box<EvalAltResult>> {
        let ix = 42;
        let iy = math::add_two_ints(ix, 1);
        [fy, iy]
-       "#
+       "#,
     )?;
     assert_eq!(&output_array[0].as_float().unwrap(), &43.0);
     assert_eq!(&output_array[1].as_int().unwrap(), &43);
@@ -253,7 +253,7 @@ fn raw_returning_fn_test() -> Result<(), Box<EvalAltResult>> {
     let mut engine = Engine::new();
     engine.register_fn("get_mystic_number", || 42 as FLOAT);
     let mut m = Module::new();
-    rhai::register_exported_fn!(
+    rhai::set_exported_fn!(
         m,
         "euclidean_distance".to_string(),
         raw_returning_fn::distance_function

src/plugin.rs

@@ -11,6 +11,7 @@ pub use crate::{
     ImmutableString,
     Module,
     Position,
+    RegisterResultFn,
 };
 
 pub use rhai_codegen::*;