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Julien Fontanet 471fbef6ef chore: hide USAGE.md This highlight the fact that it's not designed for direct consumption and it no longer needs a special handling in `npmignore`.		2022-02-18 17:11:52 +01:00
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.npmignore	feat(@vates/predicates): utils to compose predicates	2022-02-10 16:55:15 +01:00
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index.js	fix(predicates): use strict mode	2022-02-18 17:03:21 +01:00
index.spec.js	chore(predicates): add tests	2022-02-18 17:03:21 +01:00
package.json	chore(predicates): add tests	2022-02-18 17:03:21 +01:00
README.md	feat(@vates/predicates): utils to compose predicates	2022-02-10 16:55:15 +01:00

README.md

@vates/predicates

Utilities to compose predicates

Install

Installation of the npm package:

> npm install --save @vates/predicates

Usage

undefined predicates are ignored and undefined is returned if all predicates are undefined, this permits the most efficient composition:

const compositePredicate = every(undefined, some(predicate2, undefined))

// ends up as

const compositePredicate = predicate2

Predicates can also be passed wrapped in an array:

const compositePredicate = every([predicate1, some([predicate2, predicate3])])

this and all arguments are passed to the nested predicates.

`every(predicates)`

Returns a predicate that returns true iff every predicate returns true.

const isBetween3And7 = every(
  n => n >= 3,
  n => n <= 7
)

isBetween3And10(0)
// → false

isBetween3And10(5)
// → true

isBetween3And10(10)
// → false

`some(predicates)`

Returns a predicate that returns true iff some predicate returns true.

const isAliceOrBob = some(
  name => name === 'Alice',
  name => name === 'Bob'
)

isAliceOrBob('Alice')
// → true

isAliceOrBob('Bob')
// → true

isAliceOrBob('Oscar')
// → false

Contributions

Contributions are very welcomed, either on the documentation or on the code.

You may:

report any issue you've encountered;
fork and create a pull request.