This a crate providing an easy way of constructing parsers which can easily parse various programming languages. It has much of the same API as Text.Parsec.Token but are otherwise a bit different to fit in to the ownership model of rust. The crate is an extension of the combine crate.
rust
extern crate combine;
extern crate combine_language;
use combine::{satisfy, Parser};
use combine::char::{alpha_num, letter, string};
use combine_language::{Identifier, LanguageEnv, LanguageDef};
fn main() {
let env = LanguageEnv::new(LanguageDef {
ident: Identifier {
start: letter(),
rest: alpha_num(),
reserved: ["if", "then", "else", "let", "in", "type"].iter()
.map(|x| (*x).into())
.collect(),
},
op: Identifier {
start: satisfy(|c| "+-*/".chars().any(|x| x == c)),
rest: satisfy(|c| "+-*/".chars().any(|x| x == c)),
reserved: ["+", "-", "*", "/"].iter().map(|x| (*x).into()).collect()
},
comment_start: string("/*").map(|_| ()),
comment_end: string("*/").map(|_| ()),
comment_line: string("//").map(|_| ()),
});
let id = env.identifier();//An identifier parser
let integer = env.integer();//An integer parser
let result = (id, integer).easy_parse("this /* Skips comments */ 42");
assert_eq!(result, Ok(((String::from("this"), 42), "")));
}