Select

Function for selecting things.

selector(spec)

The selector() function can be used to create a function that will select things based on a number of different specifications. It is used in various other utility functions including hash() and extract().

import { selector } from '@abw/badger-utils'

If passed an object it will return a selection function that will return true for items that have a true-like value in the object or false otherwise. It uses the Boolean() function to test for trueness.

const select = selector({ foo: true, bar: 1, baz: false })

select('foo')       // true
select('bar')       // true
select('baz')       // false
select('qux')       // false

If passed an array it will convert the array to an object with each item in the array being set to true.

const select = selector(['foo', 'bar'])

select('foo')       // true
select('bar')       // true
select('baz')       // false
select('qux')       // false

If passed a string it will split it on whitespace and/or commas and create an object as above.

const select = selector('foo bar')  // or 'foo,bar', 'foo, bar'

select('foo')       // true
select('bar')       // true
select('baz')       // false
select('qux')       // false

If passed a regular expression it will return true for candidates that match it.

const select = selector(/^foo|bar$/)

select('foo')       // true
select('bar')       // true
select('baz')       // false
select('qux')       // false

If passed a function then it simply returns the function unchanged.

const select = selector( item => item === 'foo' || item === 'bar' )

select('foo')       // true
select('bar')       // true
select('baz')       // false
select('qux')       // false