Array extras for regular expressions.
Also provides optional String
and RegExp
prototype extensions.
No more writing the implementation-detail-leaking, non-semantic, and otherwise ugly:
let matches; while ((matches = regex.exec(str)) !== null) { // Do something if (condition) { break; } }
While all of the array extras could be useful, some
, might be the most general purpose as it (as with every
) allows short-circuiting (breaking).
The following is equivalent to that above (though with matches
as local):
RegExtras(regex).some(str, (matches) => { // Do something if (condition) { return true; } return false; });
And if the condition is at the end of the loop, just this:
RegExtras(regex).some(str, (matches) => { // Do something return condition; });
Node:
const RegExtras = require('regextras');
Modern browsers:
import {RegExtras} from './node_modules/regextras/dist/index-es.js';
Older browsers:
<script src="regextras/dist/index-umd.js"></script>
The prototype versions must be required or included separately.
If you need the generator methods, you should also add the following:
<script src="regextras/dist/index-generators-umd.js"></script>
new RegExtras(regex, flags, newLastIndex)
Example:
const piglatinArray = RegExtras(/\w*w?ay/).reduce('ouyay areway illysay', function (arr, i, word) { if (word.endsWith('way')) { arr.push(word.replace(/way$/, '')); } else { arr.push(word.slice(-3, -2) + word.slice(0, -3)); } return arr; }, []);
All arguments but the first are optional, and the first argument can be expressed as a string.
The new
keywords is not required.
These methods (and their callbacks) behave like the array extra to which they correspond with exceptions detailed below.
forEach(str, callback, thisObject) - Unlike the other extras, this method returns the RegExtras object (to enable chaining).
some(str, callback, thisObject)
every(str, callback, thisObject)
map(str, callback, thisObject)
filter(str, callback, thisObject)
reduce(str, cb, prev, thisObj) - Unlike the array extras, allows a fourth argument to set an alternative value for this
within the callback.
reduceRight(str, cb, prev, thisObj) - Unlike the array extras, allows a fourth argument to set an alternative value for this
within the callback.
find(str, cb, thisObj)
findIndex(str, cb, thisObj)
Also adds the following methods:
findExec(str, cb, thisObj) - Operates like find()
except that it returns the exec
result array (with index
and input
as well as numeric properties as returned by RegExp.prototype.exec).
filterExec(str, cb, thisObj) - Operates like filter()
except that the resulting array will contain the full exec
results.
If you are using the Node version (or if, for the browser, you add the index-generators.js
file and you are only supporting modern browsers), one can use the following generator methods:
values(str) - Returns an iterator with the array of matches (for each RegExp.prototype.exec
result)
keys(str) - Returns an iterator with 0-based indexes (from RegExp.prototype.exec
result)
entries(str) - Returns an iterator with an array containing the key and the array of matches (for each RegExp.prototype.exec
result)
All callbacks follow the signature:
cb(n1, n2..., i, n0);
...except for the reduce
and reduceRight
callbacks which follow:
cb(prev, n1, n2..., i, n0);
String
and RegExp
versions of the above methods are also available.
The RegExp
prototype version acts in the same way as RegExtra
just without the need for a separate constructor call.
The String
prototype version differs in that instead of the first argument being a string, it is the regular expression.
Could add Array accessor methods like slice()
, with an additional supplied regular expression to gather the exec
results into an array.
Utilize nodeunit
browser testing (and add mixinRegex
tests)
test
with tests
folderAdd generators for prototype versions