SRL - Simple Regex Language
Regular Expressions Made Simple

Lookarounds

Lookarounds provide you with an easy way of applying conditions to your expressions. Think if them as simple if-statements: If that happened, match this.

if followed by / if not followed by

if [not] followed by

Sometimes, you may only want to match a certain condition if it is directly followed by a given other condition.

This can be done using lookahead. In SRL, a lookahead can be positive (if followed by) or negative (if not followed by). The example below will only capture the number, if it's no more followed by any other number.

Example query:

capture (digit) if not followed by (anything once or more, digit)

Test Input

Run Query!

SRL Query is matching!

SRL Query is not matching.

The SRL Query contains an error:

Whoops... you may have found a bug.

Generated Regular Expression:


        

if already had / if not already had

if [not] already had

Just like a lookahead, the lookbehind, which can be positive and negative as well, matches the characters exactly before that condition.

For example, you may only want to match bar if it's directly following foo:

Example query:

capture "bar" if already had "foo"

Test Input

Run Query!

SRL Query is matching!

SRL Query is not matching.

The SRL Query contains an error:

Whoops... you may have found a bug.

Generated Regular Expression: