partition-array

Linear time in place array partitioning. Similar to Array.filter, but faster as it does not make a copy.

Example

var partition = require('partition-array')
var array = [1, 0, -1, 10, -5, 6, -8, -7]

var split = partition(array, function(x) {
  return x < 0
})

console.log('partition @', split)
console.log(array)
console.log('<0   ~', array.slice(0, split))
console.log('>=0  ~', array.slice(split))

Output:

partition @ 4
[ -1, -5, -8, -7, 0, 6, 1, 10 ]
<0   ~ [ -1, -5, -8, -7 ]
>=0  ~ [ 0, 6, 1, 10 ]

Install

npm install partition-array

API

var split = require('partition-array')(array, pred[, lo, hi])

Partitions the array into two contiguous regions based on predicate.

• array is the array which is to be partitioned
• pred is the predicate which is being tested
• lo is an optional parameter denoting the start of the subarray to partition (default 0)
• hi is an optional parameter denoting the end of the subarray to partition (default array.length)

Returns The point at which the array was split. For elements in the array before index mid, pred is true; for elements after mid pred is false.

License

(c) 2015 Mikola Lysenko. MIT License