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#![recursion_limit="256"]
extern crate proc_macro;
#[macro_use]
extern crate quote;
extern crate relm_derive_common;
extern crate relm_gen_widget;
extern crate syn;
use proc_macro::TokenStream;
use relm_gen_widget::gen_widget;
use relm_derive_common::{impl_msg, impl_simple_msg};
use syn::{
Ident,
Item,
ItemStruct,
parse,
};
use syn::Type::Macro;
use syn::spanned::Spanned;
#[proc_macro_derive(SimpleMsg)]
pub fn simple_msg(input: TokenStream) -> TokenStream {
let ast: Item = parse(input).expect("simple_msg > parse failed");
let gen = impl_simple_msg(&ast, Ident::new("relm", ast.span()));
gen.into()
}
#[proc_macro_derive(Msg)]
pub fn msg(input: TokenStream) -> TokenStream {
let ast: Item = parse(input).expect("msg > parse failed");
let gen = impl_msg(&ast, Ident::new("relm", ast.span()));
gen.into()
}
#[proc_macro_derive(Widget)]
pub fn widget(input: TokenStream) -> TokenStream {
let ast: Item = parse(input).expect("widget > parse failed");
let expanded = impl_widget(&ast);
expanded.into()
}
fn impl_widget(ast: &Item) -> TokenStream {
if let Item::Struct(ItemStruct { ref fields, ..}) = *ast {
for field in fields {
if let Some(ref ident) = field.ident {
if ident == "widget" {
if let Macro(ref mac) = field.ty {
let tts = &mac.mac.tts;
let tokens = quote! {
#tts
};
return gen_widget(tokens.into()).into();
}
}
}
}
}
panic!("Expecting `widget` field.");
}