rust/src/libsyntax/ext/pipes/parse_proto.rs
2013-03-04 12:27:01 -05:00

126 lines
3.5 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 ast_util;
use ext::pipes::proto::*;
use parse::common::SeqSep;
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);
}
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,
SeqSep {
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 = copy *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 generics = if *self.token == token::LT {
self.parse_generics()
} else {
ast_util::empty_generics()
};
let state = proto.add_state_poly(name, id, dir, generics);
// parse the messages
self.parse_unspanned_seq(
&token::LBRACE,
&token::RBRACE,
SeqSep {
sep: Some(token::COMMA),
trailing_sep_allowed: true,
},
|self| self.parse_message(state)
);
}
fn parse_message(&self, state: state) {
let mname = copy *self.interner.get(self.parse_ident());
let args = if *self.token == token::LPAREN {
self.parse_unspanned_seq(
&token::LPAREN,
&token::RPAREN,
SeqSep {
sep: Some(token::COMMA),
trailing_sep_allowed: true,
},
|p| p.parse_ty(false)
)
}
else { ~[] };
self.expect(&token::RARROW);
let next = match *self.token {
token::IDENT(_, _) => {
let name = copy *self.interner.get(self.parse_ident());
let ntys = if *self.token == token::LT {
self.parse_unspanned_seq(
&token::LT,
&token::GT,
SeqSep {
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, *self.span, args, next);
}
}