rust/tests/ui/proc-macro/auxiliary/count_compound_ops.rs

33 lines
847 B
Rust

//@ force-host
//@ no-prefer-dynamic
#![feature(proc_macro_quote)]
#![crate_type = "proc-macro"]
extern crate proc_macro;
use proc_macro::{TokenStream, TokenTree, Spacing, Literal, quote};
#[proc_macro]
pub fn count_compound_ops(input: TokenStream) -> TokenStream {
assert_eq!(count_compound_ops_helper(quote!(++ (&&) 4@a)), 3);
let l = Literal::u32_suffixed(count_compound_ops_helper(input));
TokenTree::from(l).into()
}
fn count_compound_ops_helper(input: TokenStream) -> u32 {
let mut count = 0;
for token in input {
match &token {
TokenTree::Punct(tt) if tt.spacing() == Spacing::Alone => {
count += 1;
}
TokenTree::Group(tt) => {
count += count_compound_ops_helper(tt.stream());
}
_ => {}
}
}
count
}