Move attribute arg parsing to module

Author: dtolnay

src/args.rs

@@ -0,0 +1,18 @@
+use syn::parse::{Parse, ParseStream, Result};
+
+pub struct Args {
+    pub local: bool
+}
+
+mod kw {
+    syn::custom_keyword!(local);
+}
+
+impl Parse for Args {
+    fn parse(input: ParseStream) -> Result<Self> {
+        let local: Option<kw::local> = input.parse()?;
+        Ok(Args {
+            local: local.is_some(),
+        })
+    }
+}

src/lib.rs

@@ -299,25 +299,23 @@
 
 extern crate proc_macro;
 
+mod args;
 mod expand;
 mod lifetime;
 mod parse;
 mod receiver;
 
+use crate::args::Args;
 use crate::expand::expand;
 use crate::parse::Item;
 use proc_macro::TokenStream;
 use quote::quote;
 use syn::parse_macro_input;
 
-mod kw {
-    syn::custom_keyword!(local);
-}
-
 #[proc_macro_attribute]
 pub fn async_trait(args: TokenStream, input: TokenStream) -> TokenStream {
-    let local = parse_macro_input!(args as Option<kw::local>).is_some();
+    let args = parse_macro_input!(args as Args);
     let mut item = parse_macro_input!(input as Item);
-    expand(&mut item, local);
+    expand(&mut item, args.local);
     TokenStream::from(quote!(#item))
 }