partition-iterable

Divides iterated values into those that match a filter and those that don’t.

Installation

Requires Node.js 6.0.0 or above.

npm i partition-iterable

API

The module exports a single function.

Parameters

1. Bindable: iter (iterable): The iterable whose values should be partitioned.
2. Optional: test (any): A Function, an Array, or another value. Each iterated value from iter is tested in a manner that depends on test’s type:
   • If a Function: Does test return true when the value is passed to it?
   • If an Array: Is the value included in test?
   • If omitted or undefined: Is the value truthy?
   • Otherwise: Does the value equal test?

Return Value

A two-element Array:

1. An Array of iterated values that passed the test.
2. An Array of those that did not.

Example

const partition = require('partition-iterable')

const isEven = n => n % 2 === 0

const [even, odd] = partition([1, 2, 3, 4, 5], isEven)

even // [2, 4]
odd // [1, 3, 5]

// Supports the bind operator
[1, 2, 3, 4, 5]::partition(isEven) // [[2, 4], [1, 3, 5]]

Related

• filter-iter: Filters an iterable object so that it only yields values which pass a test function.
• reduce-iterable: Applies a function to iterated values to reduce them to a single value.
• unique-iterable: Filters an iterable object so it doesn’t yield the same value more than once.
• unique-iterable-by: Filters yielded values by testing uniqueness with an index, key, or callback.