54 lines
1.6 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.
use ast::*;
use parse::token::*;
use parse::token::Token;
use core::prelude::*;
/// Unary operators have higher precedence than binary
pub const unop_prec: uint = 100u;
/**
* Precedence of the `as` operator, which is a binary operator
* but is not represented in the precedence table.
*/
pub const as_prec: uint = 11u;
/**
* Maps a token to a record specifying the corresponding binary
* operator and its precedence
*/
pub fn token_to_binop(tok: Token) -> Option<ast::binop> {
match tok {
BINOP(STAR) => Some(mul),
BINOP(SLASH) => Some(div),
BINOP(PERCENT) => Some(rem),
// 'as' sits between here with 11
BINOP(PLUS) => Some(add),
BINOP(MINUS) => Some(subtract),
BINOP(SHL) => Some(shl),
BINOP(SHR) => Some(shr),
BINOP(AND) => Some(bitand),
BINOP(CARET) => Some(bitxor),
BINOP(OR) => Some(bitor),
LT => Some(lt),
LE => Some(le),
GE => Some(ge),
GT => Some(gt),
EQEQ => Some(eq),
NE => Some(ne),
ANDAND => Some(and),
OROR => Some(or),
_ => None
}
}