Expressions allows to play with regular expressions*. Just type your pattern and some text to test it. All the changes are updated while you're typing text or pattern. App highlights the syntax, so the pattern is easy-to-read and modify. If you use subexpressions (groups), you can highlight them by pressing cmd+shift+] (or [ – for decreasing the highlighted group number).
If you don't remember the regex syntax, just press cmd+r or click button in the top-right. You will get the reference sheet, so you don't have to remember everything.
The user interface is very minimalistic and non-distractive. By default the color is the same as your menubar, but you can always switch to dark or light mode (see: Preferences). You can also open app in beautiful full screen mode which is perfect when you want to focus or to demonstrate regular expressions to other people.
* Expressions uses ICU regular expression standard. More information you will find here: https://developer.apple.com/reference/foundation/nsregularexpression
- fixed bug that appeared on macOS 10.11
Ratings and Reviews
Did not live up to expectations
I expected that the application will show different groups.
But it shows everything monolithically.
Text for example: "...1...2...3..."
Expression for example: "(?<char1>1).*(?<char2>2)"
Application result: hightlighted symbols "1...2"
Expected result: hightlighted symbols "1", "2"
PHP preg_match result: ["0" => "...1...2...3...", "char"' => "1", "char2" => "2"]
p.s. See the RegExRX for view the "ideal" visualization of result.
Developer Response ,
By default Expressions highlights the 0th group which is the whole regex.
To highlight a group, press cmd+shift+} (Menu View -> Highlight next group).
This app is great
This app is great
Best tool for quickly developing and testing regular expressions
The primary feature that was previously lacking was the inclusion of a quick little reference sheet, but that has been added in this release. Expressions is functionally equivalent to the other regex apps in most regards, but has a much cleaner design. For that reason, it has become my goto app for quickly developing and testing regular expressions.
Lastly, I just want to note that the developer is also very friendly and quick to respond to feedback/suggestions. 👍🏼
With Family Sharing set up, up to six family members can use this app.