rust/src/libsyntax/ext/pipes/parse_proto.rs
2013-02-17 05:25:26 -05:00

105 lines
3.3 KiB
Rust

// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
// Parsing pipes protocols from token trees.
use ext::pipes::pipec::*;
use parse::parser;
use parse::token;
use core::prelude::*;
pub trait proto_parser {
fn parse_proto(&self, id: ~str) -> protocol;
fn parse_state(&self, proto: protocol);
fn parse_message(&self, state: state);
}
pub impl proto_parser for parser::Parser {
fn parse_proto(&self, id: ~str) -> protocol {
let proto = protocol(id, self.span);
self.parse_seq_to_before_end(token::EOF,
{sep: None, trailing_sep_allowed: false},
|self| self.parse_state(proto));
return proto;
}
fn parse_state(&self, proto: protocol) {
let id = self.parse_ident();
let name = *self.interner.get(id);
self.expect(token::COLON);
let dir = match copy self.token {
token::IDENT(n, _) => self.interner.get(n),
_ => fail!()
};
self.bump();
let dir = match dir {
@~"send" => send,
@~"recv" => recv,
_ => fail!()
};
let typarms = if self.token == token::LT {
self.parse_ty_params()
}
else { ~[] };
let state = proto.add_state_poly(name, id, dir, typarms);
// parse the messages
self.parse_unspanned_seq(
token::LBRACE, token::RBRACE,
{sep: Some(token::COMMA), trailing_sep_allowed: true},
|self| self.parse_message(state));
}
fn parse_message(&self, state: state) {
let mname = *self.interner.get(self.parse_ident());
let args = if self.token == token::LPAREN {
self.parse_unspanned_seq(token::LPAREN,
token::RPAREN,
{sep: Some(token::COMMA),
trailing_sep_allowed: true},
|p| p.parse_ty(false))
}
else { ~[] };
self.expect(token::RARROW);
let next = match copy self.token {
token::IDENT(_, _) => {
let name = *self.interner.get(self.parse_ident());
let ntys = if self.token == token::LT {
self.parse_unspanned_seq(token::LT,
token::GT,
{sep: Some(token::COMMA),
trailing_sep_allowed: true},
|p| p.parse_ty(false))
}
else { ~[] };
Some(next_state {state: name, tys: ntys})
}
token::NOT => {
// -> !
self.bump();
None
}
_ => self.fatal(~"invalid next state")
};
state.add_message(mname, copy self.span, args, next);
}
}