mirror of
https://github.com/rust-lang/rust.git
synced 2025-05-14 02:49:40 +00:00
37 lines
1.4 KiB
Rust
37 lines
1.4 KiB
Rust
|
// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
|
||
|
|
// file at the top-level directory of this distribution and at
|
||
|
|
// http://rust-lang.org/COPYRIGHT.
|
||
|
|
//
|
||
|
|
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
|
||
|
|
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
|
||
|
|
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
|
||
|
|
// option. This file may not be copied, modified, or distributed
|
||
|
|
// except according to those terms.
|
||
|
|
|
||
|
|
// no-prefer-dynamic
|
||
|
|
|
||
|
|
#![crate_type = "proc-macro"]
|
||
|
|
|
||
|
|
extern crate proc_macro;
|
||
|
|
use proc_macro::*;
|
||
|
|
|
||
|
|
#[proc_macro]
|
||
|
|
pub fn check(input: TokenStream) -> TokenStream {
|
||
|
|
// Parsed `x2` can refer to `x2` from `input`
|
||
|
|
let parsed1: TokenStream = "let x3 = x2;".parse().unwrap();
|
||
|
|
// `x3` parsed from one string can refer to `x3` parsed from another string.
|
||
|
|
let parsed2: TokenStream = "let x4 = x3;".parse().unwrap();
|
||
|
|
// Manually assembled `x4` can refer to parsed `x4`.
|
||
|
|
let manual: Vec<TokenTree> = vec![
|
||
|
|
Ident::new("let", Span::call_site()).into(),
|
||
|
|
Ident::new("x5", Span::call_site()).into(),
|
||
|
|
Punct::new('=', Spacing::Alone).into(),
|
||
|
|
Ident::new("x4", Span::call_site()).into(),
|
||
|
|
Punct::new(';', Spacing::Alone).into(),
|
||
|
|
];
|
||
|
|
input.into_iter().chain(parsed1.into_iter())
|
||
|
|
.chain(parsed2.into_iter())
|
||
|
|
.chain(manual.into_iter())
|
||
|
|
.collect()
|
||
|
|
}
|