Regex Reference

A concise reference for developer text workflows.

Pattern matching versus transformation

A regular expression describes text patterns. It can help identify lines or regions, but a safe transformation still requires an explicit decision about what should change.

Useful concepts

• Line anchors identify positions at line boundaries when multiline semantics are enabled.
• Whitespace classes match whitespace in many regex engines, but exact semantics vary.
• Capturing groups can preserve pieces of text while replacing matched regions.

Do not overgeneralize

Regex is not automatically the right tool for every cleanup job. For simple whole-line operations, explicit line processing is often easier to reason about and test.