Refine derive macro.

codegen/src/custom_type.rs

@@ -6,38 +6,100 @@ pub fn derive_custom_type_impl(input: DeriveInput) -> TokenStream {
     let name = input.ident;
 
     let accessors = match input.data {
-        syn::Data::Struct(ref data) => match data.fields {
-            syn::Fields::Named(ref fields) => {
-                let iter = fields.named.iter().map(|field| {
-                    let mut get_fn = None;
-                    let mut set_fn = None;
-                    let mut readonly = false;
-                    for attr in field.attrs.iter() {
-                        if attr.path().is_ident("get") {
-                            get_fn = Some(
-                                attr.parse_args()
-                                    .unwrap_or_else(syn::Error::into_compile_error),
-                            );
-                        } else if attr.path().is_ident("set") {
-                            set_fn = Some(
-                                attr.parse_args()
-                                    .unwrap_or_else(syn::Error::into_compile_error),
-                            );
-                        } else if attr.path().is_ident("readonly") {
-                            readonly = true;
+        syn::Data::Struct(syn::DataStruct {
+            fields: syn::Fields::Named(ref fields),
+            ..
+        }) => {
+            let iter = fields.named.iter().map(|field| {
+                let mut name = None;
+                let mut get_fn = None;
+                let mut set_fn = None;
+                let mut readonly = false;
+                let mut skip = false;
+
+                for attr in field.attrs.iter() {
+                    if attr.path().is_ident("rhai_custom_type_skip") {
+                        if get_fn.is_some() || set_fn.is_some() || name.is_some() {
+                            return syn::Error::new(
+                                Span::call_site(),
+                                "cannot use 'rhai_custom_type_skip' with other attributes",
+                            )
+                            .into_compile_error();
                         }
+
+                        skip = true;
+                        continue;
                     }
 
-                    generate_accessor_fns(&field.ident.as_ref().unwrap(), get_fn, set_fn, readonly)
-                });
-                quote! {#(#iter)*}
-            }
-            syn::Fields::Unnamed(_) => {
-                syn::Error::new(Span::call_site(), "tuple structs are not yet implemented")
-                    .into_compile_error()
-            }
-            syn::Fields::Unit => quote! {},
-        },
+                    if skip {
+                        return syn::Error::new(
+                            Span::call_site(),
+                            "cannot use 'rhai_custom_type_skip' with other attributes",
+                        )
+                        .into_compile_error();
+                    }
+
+                    if attr.path().is_ident("rhai_custom_type_name") {
+                        name = Some(
+                            attr.parse_args()
+                                .unwrap_or_else(syn::Error::into_compile_error),
+                        );
+                    } else if attr.path().is_ident("rhai_custom_type_get") {
+                        get_fn = Some(
+                            attr.parse_args()
+                                .unwrap_or_else(syn::Error::into_compile_error),
+                        );
+                    } else if attr.path().is_ident("rhai_custom_type_set") {
+                        if readonly {
+                            return syn::Error::new(
+                                Span::call_site(),
+                                "cannot use 'rhai_custom_type_set' with 'rhai_custom_type_readonly'",
+                            )
+                            .into_compile_error();
+                        }
+                        set_fn = Some(
+                            attr.parse_args()
+                                .unwrap_or_else(syn::Error::into_compile_error),
+                        );
+                    } else if attr.path().is_ident("rhai_custom_type_readonly") {
+                        if set_fn.is_some() {
+                            return syn::Error::new(
+                                Span::call_site(),
+                                "cannot use 'rhai_custom_type_readonly' with 'rhai_custom_type_set'",
+                            )
+                            .into_compile_error();
+                        }
+                        readonly = true;
+                    }
+                }
+
+                if !skip {
+                    generate_accessor_fns(
+                        &field.ident.as_ref().unwrap(),
+                        name,
+                        get_fn,
+                        set_fn,
+                        readonly,
+                    )
+                } else {
+                    quote! {}
+                }
+            });
+
+            quote! {#(#iter)*}
+        }
+
+        syn::Data::Struct(syn::DataStruct {
+            fields: syn::Fields::Unnamed(_),
+            ..
+        }) => syn::Error::new(Span::call_site(), "tuple structs are not yet implemented")
+            .into_compile_error(),
+
+        syn::Data::Struct(syn::DataStruct {
+            fields: syn::Fields::Unit,
+            ..
+        }) => quote! {},
+
         syn::Data::Enum(_) => {
             syn::Error::new(Span::call_site(), "enums are not yet implemented").into_compile_error()
         }
@@ -47,8 +109,8 @@ pub fn derive_custom_type_impl(input: DeriveInput) -> TokenStream {
     };
 
     quote! {
-        impl ::rhai::CustomType for #name {
-            fn build(mut builder: ::rhai::TypeBuilder<Self>) {
+        impl CustomType for #name {
+            fn build(mut builder: TypeBuilder<Self>) {
                 #accessors;
             }
         }
@@ -57,6 +119,7 @@ pub fn derive_custom_type_impl(input: DeriveInput) -> TokenStream {
 
 fn generate_accessor_fns(
     field: &Ident,
+    name: Option<TokenStream>,
     get: Option<TokenStream>,
     set: Option<TokenStream>,
     readonly: bool,
@@ -69,17 +132,17 @@ fn generate_accessor_fns(
         .map(|func| quote! {#func})
         .unwrap_or_else(|| quote! {|obj: &mut Self, val| obj.#field = val});
 
+    let name = name
+        .map(|field| quote! { #field })
+        .unwrap_or_else(|| quote! { stringify!(#field) });
+
     if readonly {
         quote! {
-            builder.with_get("#field", #get);
+            builder.with_get(#name, #get);
         }
     } else {
         quote! {
-            builder.with_get_set(
-                "#field",
-                #get,
-                #set,
-            );
+            builder.with_get_set(#name, #get, #set);
         }
     }
 }

codegen/src/lib.rs

@@ -410,7 +410,16 @@ pub fn set_exported_global_fn(args: proc_macro::TokenStream) -> proc_macro::Toke
     }
 }
 
-#[proc_macro_derive(CustomType, attributes(get, set, readonly))]
+#[proc_macro_derive(
+    CustomType,
+    attributes(
+        rhai_custom_type_name,
+        rhai_custom_type_get,
+        rhai_custom_type_set,
+        rhai_custom_type_readonly,
+        rhai_custom_type_skip
+    )
+)]
 pub fn derive_custom_type(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
     let input = parse_macro_input!(input as DeriveInput);
     let expanded = custom_type::derive_custom_type_impl(input);

codegen/tests/test_derive.rs

@@ -1,15 +1,25 @@
-use rhai_codegen::CustomType;
+use rhai::{CustomType, TypeBuilder, INT};
 
 // Sanity check to make sure everything compiles
 #[derive(Clone, CustomType)]
 pub struct Foo {
-    #[get(get_bar)]
-    bar: i32,
-    #[readonly]
+    #[rhai_custom_type_skip]
+    _dummy: INT,
+    #[rhai_custom_type_get(get_bar)]
+    bar: INT,
+    #[rhai_custom_type_name("boo")]
+    #[rhai_custom_type_readonly]
     baz: String,
-    qux: Vec<i32>,
+    #[rhai_custom_type_set(Self::set_qux)]
+    qux: Vec<INT>,
 }
 
-fn get_bar(_this: &mut Foo) -> i32 {
+impl Foo {
+    pub fn set_qux(&mut self, value: Vec<INT>) {
+        self.qux = value;
+    }
+}
+
+fn get_bar(_this: &mut Foo) -> INT {
     42
 }

tests/build_type.rs

@@ -1,8 +1,8 @@
 #![cfg(not(feature = "no_object"))]
-use rhai::{CustomType, Engine, EvalAltResult, Position, TypeBuilder, INT};
+use rhai::{CustomType, Engine, EvalAltResult, Position, Scope, TypeBuilder, INT};
 
 #[test]
-fn build_type() {
+fn test_build_type() {
     #[derive(Debug, Clone, PartialEq, Eq)]
     struct Vec3 {
         x: INT,
@@ -32,7 +32,7 @@
         fn set_z(&mut self, z: INT) {
             self.z = z
         }
         fn get_component(&mut self, idx: INT) -> Result<INT, Box<EvalAltResult>> {
             match idx {
                 0 => Ok(self.x),
                 1 => Ok(self.y),
@@ -156,3 +156,69 @@
         6,
     );
 }
+
+#[test]
+fn test_build_type_macro() {
+    #[derive(Debug, Clone, Eq, PartialEq)] // <- necessary for any custom type
+    #[derive(CustomType)] // <- auto-implement 'CustomType'
+    struct Foo {
+        #[rhai_custom_type_skip]
+        dummy: i64, // <- skip this field
+        #[rhai_custom_type_readonly] // <- only auto-implement getters
+        bar: i64,
+        #[rhai_custom_type_name("emphasize")]
+        baz: bool, // <- auto-implement getter/setter for 'baz'
+        #[rhai_custom_type_set(Self::set_hello)] // <- call custom setter for 'hello'
+        hello: String, // <- auto-implement getter for 'hello'
+    }
+
+    impl Foo {
+        pub fn set_hello(&mut self, value: String) {
+            self.hello = if self.baz {
+                let mut s = self.hello.clone();
+                s.push_str(&value);
+                for _ in 0..self.bar {
+                    s.push('!');
+                }
+                s
+            } else {
+                value
+            };
+        }
+    }
+
+    let mut engine = Engine::new();
+    engine.build_type::<Foo>();
+
+    let mut scope = Scope::new();
+    scope.push(
+        "foo",
+        Foo {
+            dummy: 0,
+            bar: 5,
+            baz: false,
+            hello: "hey".to_string(),
+        },
+    );
+
+    assert_eq!(
+        engine
+            .eval_with_scope::<Foo>(
+                &mut scope,
+                r#"
+                    foo.hello = "this should not be seen";
+                    foo.hello = "world!";
+                    foo.emphasize = true;
+                    foo.hello = "yo";
+                    foo
+                "#
+            )
+            .unwrap(),
+        Foo {
+            dummy: 0,
+            bar: 5,
+            baz: true,
+            hello: "world!yo!!!!!".into()
+        }
+    );
+}