2017-03-30 23:06:28 -05:00
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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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2018-07-03 17:36:31 -05:00
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#![feature(use_extern_macros, proc_macro_quote, proc_macro_non_items)]
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2017-03-30 23:06:28 -05:00
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#![crate_type = "proc-macro"]
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extern crate proc_macro as proc_macro_renamed; // This does not break `quote!`
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use proc_macro_renamed::{TokenStream, quote};
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#[proc_macro]
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pub fn hello(input: TokenStream) -> TokenStream {
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quote!(hello_helper!($input))
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//^ `hello_helper!` always resolves to the following proc macro,
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//| no matter where `hello!` is used.
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}
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#[proc_macro]
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pub fn hello_helper(input: TokenStream) -> TokenStream {
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quote! {
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extern crate hygiene_example; // This is never a conflict error
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let string = format!("hello {}", $input);
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//^ `format!` always resolves to the prelude macro,
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//| even if a different `format!` is in scope where `hello!` is used.
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hygiene_example::print(&string)
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}
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}
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