# regex ## Reference - [history behind that 2 problems quote](x-devonthink-item://CC6DF9A1-4FED-4496-85FD-1BF4F55F0F26) ### Tools - [regex explainer and tester in multiple languages](https://regex101.com/) - [regular expression compilation visualized](https://compiler.org/reason-re-nfa/src/index.html)