split-limit

split-limit

Splits a string into limited length of substrings, but keep last substring unsplit.

Splits a String into an array of substrings, by passing parameter limit, only divide limit-1 times. and unlike String.prototype.split(), the last substring will be the unsplit remainder. it is more like ruby's split, php's explode/preg_split, golang's strings.SplitN/Regexp.Split function

Syntax

function splitLimit(string, separator, [limit = undefined], [options = {isKeepSubmatches: false} ]) {

}

Parameters

string String

the string need to be split

separator String|RegExp

if separator is a RegExp, string is divided where the separator regexp matches, and if separator regexp contains groups, the last parameter options will decide how to treat submatches

limit Integer (Optional)

Optional Integer specifying a limit on the number of splits to be found, unlike String.prototype.split(), it will only split limit-1 times (if limit is >= 1), normally it will return limit size array of substrings. if not set or set to null or set to isNaN, is equivalent to String.prototype.split() if set to <= 0, it will split all matched.(means there is no limited)

options Object (Optional)

decides to ignore or keep submatches while separator is a regexp and contains groups. if options is not been set or set to {isKeepSubmatches: false}, then submatches will be dropped. like php/golang does. if options is set to {isKeepSubmatches: true}, then submatches will be returned in the result array, followed after split value and the result array size maybe large than limit, like js/ruby/perl does (unless you know it exactly, otherwise just ignore it).

Usage

var splitLimit = require('split-limit');
var str = 'user-agent: Mozilla/5.0, OS: Mac, Arch:  amd64';

var splits = splitLimit(str, /:\s+/, 2);
// ==> [ 'user-agent', 'Mozilla/5.0, OS: Mac, Arch:  amd64' ]


// separator is regexp and contains groups
var str2 = 'apple *-* pear  .+.  melon ^-^ banana';
var splits2 = splitLimit(str2, /\s*([^-+])([-+])([^-+])\s*/, 3);
// ==> [ 'apple', 'pear', 'melon ^-^ banana' ]

// keep the submatches
var splits2_keep = splitLimit(str2, /\s*([^-+])([-+])([^-+])\s*/, 3, {
  isKeepSubmatches: true
});
// ==> [ 'apple', '*', '-', '*', 'pear', '.', '+', '.', 'melon ^-^ banana' ]


// split with string
// limit <=0 will split with all matched substrings.
splitLimit('write|read|create|lock', '|', -1);
// ==> [ 'write', 'read', 'create', 'lock' ]

// split with regexp and limit is -1, unlike String.prototype.split(), it ignored submatches!
splitLimit('apple - pear  -  melon - banana', /\s*(-)\s*/, -1);
// ==> ['apple', 'pear', 'melon', 'banana']
// if you want to keep submatches like String.prototype.split(), set options to {isKeepSubmatches: true}

Enjoy!

License

MIT © Jesse