Faster Coding with regular Expressions

Expressions is a sleek and simple app for coding with regular expressions. The app’s pared-down interface gives clarity to your work, highlighting the syntax in real time as you build up expressions. Plus, with a built-in library of metacharacters, you’ll never be stuck if you forget an expression.

How to use Expressions

Regular expressions are extremely useful to save development time. It allows to extract information from text such as code, log files, or documents. Learn how to use Expressions app for pattern matching.

Create new expressions

To create a new expression, click the (+) button at the bottom left of the screen, then name it. You can enter your expression manually in the upper text box, or copy-paste from somewhere else.

The app will automatically break up your expression according to syntax, and prompt you if the expression is invalid. Enter sample strings in the lower box to test for matches.

Add new expressions

Appearance and display

To adjust the display, click “Expressions” in the Menubar and select “Preferences.” This window lets you adjust the display theme, choosing “light,” “dark,” or “default.” It also gives you some control over the text fields, allowing you to choose the conditions under which your expressions will be displayed.


Character library

Regular expressions depend on a variety of metacharacters, and it can be hard to memorize them all. The app eliminates that problem by including a built-in character library.

To view the library, just click the top-right button in the window. The “Basic” and “Advanced” tabs let you toggle between two character lists. These lists make it easy to check your work and fix mistakes.

Character library

Expressions is a straightforward and beautiful way to work with a deceptively complicated coding style. It supports your work without getting in the way with automatic syntax highlighting, adjustable themes, and a handy character list. Happy coding!