.. | ||
dist | ||
src | ||
.babelrc | ||
.editorconfig | ||
.eslintignore | ||
.eslintrc.js | ||
.remarkrc | ||
CHANGES.md | ||
lgtm.yml | ||
LICENSE-MIT.txt | ||
package.json | ||
README.md |
regextras
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;
});
Installation
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>
API
Constructor
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.
Instance methods
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 theexec
result array (withindex
andinput
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 fullexec
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)
Class methods
- mixinRegex(regex, newFlags='', newLastIndex=regex.lastIndex) - Makes a copy of a regular expression.
Callbacks
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);
Prototype versions
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.
Todos
-
Could add Array accessor methods like
slice()
, with an additional supplied regular expression to gather theexec
results into an array. -
Utilize
nodeunit
browser testing (and addmixinRegex
tests)- Convert nodeunit tests to ES6 modules running through babel-register?;
streamline as sole set of tests, reconciling
test
withtests
folder
- Convert nodeunit tests to ES6 modules running through babel-register?;
streamline as sole set of tests, reconciling
-
Add generators for prototype versions