parser-combinators
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1.1.3 • Public • Published

Parser Combinators

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A library of parser combinators, with which you can create your own parsers.

Parser combinators can be used for:

  • Replacing complicated regular expressions with easy-to-understand parsers
  • Incorporating custom languages into your application
  • Introducing higher-order functions and parsing concepts

This package:

  • Has full TypeScript support and is made with strict mode on
  • Is thoroughly tested
  • Is made in the Simplicity first philosophy
  • Will be continuously improved in time
As of now it contains the following combinators:
  • Standard combinators:
    • any
    • between
    • exhaust
    • many (and zeroOrMany, oneOrMany, oneOrManyRed)
    • map
    • optional
    • regex
    • sequence
    • string
  • Utility combinators:
    • refer
    • expect
    • expectErase
    • surely
  • Ready-made value combinators:
    • spaces
    • spacesPlus
    • wspaces
    • bool (and boolP)
    • int (and intP)
    • real (and realP)
  • Whole parsers:
    • Extended Backus-Naur Form (EBNF)
    • JavaScript Object Notation (JSON)

Example usage:

Using standard combinators:
import { seq, str, any } from 'parser-combinators/parsers';
import { ParseText } from 'parser-combinators';

const parser = seq(str('a'), any(str('b'), str('c')));
const result = ParseText('ab', parser); // Will return ['a', 'b']
Using ready value combinators:
import { wspaces, str, realP, map } from 'parser-combinators/parsers';
import { ParseText } from 'parser-combinators';

const parser = map(
    seq(wspaces, str('number:'), wspaces, realP, wspaces),
    ([,,, data]) => data
);
const result = ParseText(' number: 1.75  ', parser); // Will return 1.75
Using ref to expand the parser's possibilities:
import { wspaces, str, realP, map } from 'parser-combinators/parsers';
import { ParseText } from 'parser-combinators';

const parser = ref(
    map(
        seq(wspaces, str('number:'), wspaces, realP, wspaces),
        ([,,, data]) => data
    ),
    data => data > 1.5,
    'The number must be over 1.5!'
);
const result = ParseText(' number: 1.25  ', parser); // Will throw a ParseError('The number must be over 1.5!')

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npm i parser-combinators

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Version

1.1.3

License

ISC

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  • micha_i