4 #![crate_type = "proc-macro"]
6 extern crate proc_macro;
10 pub fn check(input: TokenStream) -> TokenStream {
11 // Parsed `x2` can refer to `x2` from `input`
12 let parsed1: TokenStream = "let x3 = x2;".parse().unwrap();
13 // `x3` parsed from one string can refer to `x3` parsed from another string.
14 let parsed2: TokenStream = "let x4 = x3;".parse().unwrap();
15 // Manually assembled `x4` can refer to parsed `x4`.
16 let manual: Vec<TokenTree> = vec![
17 Ident::new("let", Span::call_site()).into(),
18 Ident::new("x5", Span::call_site()).into(),
19 Punct::new('=', Spacing::Alone).into(),
20 Ident::new("x4", Span::call_site()).into(),
21 Punct::new(';', Spacing::Alone).into(),
23 input.into_iter().chain(parsed1.into_iter())
24 .chain(parsed2.into_iter())
25 .chain(manual.into_iter())