Web tools
Web pages used infrequently but worth knowing about — bookmark-style tips, no install required.
Tip 60.1: Regex visualisers and debuggers
For when a pattern works but you can't see why.
- regex101 — explains each token and steps through matches; PCRE, Python, Java, Go, Rust and more. https://regex101.com/
- RegExr — live matching with a built-in cheat sheet; JavaScript and PCRE. https://regexr.com/
- Regexper — renders a regex as a railroad diagram; JavaScript only. https://regexper.com/
- Regex Vis — railroad diagram you can also edit the regex through. https://regex-vis.com/
Tip 60.2: Monkeytype — typing practice
Clean, minimal typing trainer with WPM/accuracy stats and configurable test length, language, and word lists.
Tip 60.3: Kafka Streams Topology Visualiser
Paste the Topology#describe() output from a Kafka Streams app and get a graph of sources, processors, state stores, and sinks.
Indispensable when reasoning about a non-trivial topology.