@vates/predicates

 !License  

> 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:

`js
const compositePredicate = not(every(undefined, some(not(predicate2), undefined)))

// ends up as

const compositePredicate = predicate2
`

Predicates can also be passed wrapped in an array:

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

this and all arguments are passed to the nested predicates.

$3

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

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

isBetween3And10(0)
// → false

isBetween3And10(5)
// → true

isBetween3And10(10)
// → false
`

$3

> Returns a predicate that returns the negation of the predicate.

`js
const isEven = n => n % 2 === 0
const isOdd = not(isEven)

isOdd(1)
// true

isOdd(2)
// false
`

$3

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

`js
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.

License

ISC © Vates SAS