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npm · #4521 most downloaded on npm
Simple, transparent parser combinators toolkit that supports any tokens
Last release 1 years ago
05 Sep 2025
Ships unpredictably
gaps range from 5 weeks to 2.6 years
Nearly every release is documented
notes for 10 of 10 stable releases
Nothing withdrawn
no release was ever pulled
5 years old
10 releases · first in 2021
One column per quarter.
old name provided as a deprecated alias and will be removed in the next minor/major version;
package.json exports;core moduletakeN and takeMinMax;filter and aliases guard and refine
takeWhile now can narrow the value type if provided a type guard;satisfy now can narrow the token type if provided a type guard;choice to first - to better reflect the order of evaluation
choice and or are still available as aliases for it;last
map1 to mapR
eitherOr is now a function and otherwise is an alias for it;between added for function middle;core types: TupleOf - for better type inference in takeN.char modulechar.charTest can have two arguments: positive and negative regular expressions
char.oneOf;char types: CharUnion, GraphemeUnion - for better type inference in oneOf.many functions got overloads for Matcher type propagation in less common scenarios;
Matcher type propagation in less common scenarios;condition function now accepts Parsers/Matchers with different value types, result value type is the union of the two;Targeting Node.js version 14 and ES2020;
otherwise function now has two overloads - Parser * Matcher -> Matcher and Parser * Parser -> Parser;
otherwise function now has two overloads - Parser * Matcher -> Matcher and Parser * Parser -> Parser;otherwise function now accepts Parsers/Matchers with different value types, result value type is the union of the two;otherwise function now has an alias called eitherOr which might be more natural for combining parsers.ensure local imports have file extensions - fix "./core module cannot be found" issue.
remove terser, source-map files;
rollup-plugin-cleanup to condition published files.- source-map files; - minor documentation update.
peek function keeps Parser/Matcher distinction;
peek function keeps Parser/Matcher distinction;package marked as free of side effects for tree shaking.
Aiming at Node.js version 12 and up.
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