37 lines
1.2 KiB
Rust
37 lines
1.2 KiB
Rust
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// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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// no-prefer-dynamic
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#![feature(proc_macro)]
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#![crate_type = "proc-macro"]
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extern crate proc_macro;
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use proc_macro::{TokenStream, TokenKind, OpKind, Literal, quote};
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#[proc_macro]
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pub fn count_compound_ops(input: TokenStream) -> TokenStream {
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assert_eq!(count_compound_ops_helper(quote!(++ (&&) 4@a)), 3);
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TokenKind::Literal(Literal::u32(count_compound_ops_helper(input))).into()
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}
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fn count_compound_ops_helper(input: TokenStream) -> u32 {
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let mut count = 0;
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for token in input {
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match token.kind {
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TokenKind::Op(c, OpKind::Alone) => count += 1,
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TokenKind::Sequence(_, tokens) => count += count_compound_ops_helper(tokens),
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_ => {}
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}
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}
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count
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}
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