parsers 0.9.2

Parser combinators for Dart.

Parser Combinators for Dart

Check out the user guide (work in progress).

Quick Start

pubspec.yaml

name: demo
dependencies:
  parsers: any

bin/demo.dart

import 'package:parsers/parsers.dart';
import 'dart:math';

final number = digit.many1       ^ digits2int
             | string('none')    ^ none
             | string('answer')  ^ answer;

final comma = char(',') < spaces;

final numbers = number.sepBy(comma) < eof;


digits2int(digits) => parseInt(Strings.concatAll(digits));
none(_) => null;
answer(_) => 42;


main() {
  print(numbers.parse('0,1, none, 3,answer')); // [0, 1, null, 3, 42]
  print(numbers.parse('0,1, boom, 3,answer')); // line 1, character 6: expected digit, 'none' or 'answer', got 'b'.
}

See the example directory for advanced usage.

About

This library is heavily inspired by Parsec, but differs on some points. In particular, the | operator has a sane backtracking semantics, as in Polyparse. As a consequence it is slower but also easier to use. I've also introduced some syntax for transforming parsing results that doesn't require any knowledge of monads or applicative functors and features uncurried functions, which are nicer-looking than curried ones in Dart.