73 lines
2.3 KiB
Rust
73 lines
2.3 KiB
Rust
// Copyright 2016 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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//! This is a shim file to ease the transition to the final procedural macro interface for
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//! Macros 2.0. It currently exposes the `libsyntax` operations that the quasiquoter's
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//! output needs to compile correctly, along with the following operators:
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//!
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//! - `build_block_emitter`, which produces a `block` output macro result from the
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//! provided TokenStream.
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use ast;
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use codemap::Span;
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use parse::parser::Parser;
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use ptr::P;
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use tokenstream::TokenStream;
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use ext::base::*;
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/// Take a `ExtCtxt`, `Span`, and `TokenStream`, and produce a Macro Result that parses
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/// the TokenStream as a block and returns it as an `Expr`.
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pub fn build_block_emitter<'cx>(cx: &'cx mut ExtCtxt,
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sp: Span,
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output: TokenStream)
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-> Box<MacResult + 'cx> {
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let parser = cx.new_parser_from_tts(&output.to_tts());
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struct Result<'a> {
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prsr: Parser<'a>,
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span: Span,
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}; //FIXME is this the right lifetime
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impl<'a> Result<'a> {
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fn block(&mut self) -> P<ast::Block> {
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let res = self.prsr.parse_block().unwrap();
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res
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}
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}
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impl<'a> MacResult for Result<'a> {
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fn make_expr(self: Box<Self>) -> Option<P<ast::Expr>> {
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let mut me = *self;
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Some(P(ast::Expr {
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id: ast::DUMMY_NODE_ID,
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node: ast::ExprKind::Block(me.block()),
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span: me.span,
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attrs: ast::ThinVec::new(),
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}))
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}
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}
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Box::new(Result {
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prsr: parser,
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span: sp,
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})
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}
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pub mod prelude {
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pub use super::build_block_emitter;
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pub use ast::Ident;
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pub use codemap::{DUMMY_SP, Span};
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pub use ext::base::{ExtCtxt, MacResult};
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pub use parse::token::{self, Token, DelimToken};
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pub use symbol::keywords;
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pub use tokenstream::{TokenTree, TokenStream};
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}
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