Regex is used all over the place, so it's certainly worthwhile to speed things up. And huge FST's are also used in language tech, e.g. to analyze all frillions of the forms of Finnish verbs into all their ambiguous readings with tags and dictionary forms: https://beta.apertium.org/index.eng.html?choice=fin&qA=Taite...
The language supported by that FST is basically infinite due to derivations and compounding, but the zipped binary fits on a handful of floppies.
Regex is used all over the place, so it's certainly worthwhile to speed things up. And huge FST's are also used in language tech, e.g. to analyze all frillions of the forms of Finnish verbs into all their ambiguous readings with tags and dictionary forms: https://beta.apertium.org/index.eng.html?choice=fin&qA=Taite... The language supported by that FST is basically infinite due to derivations and compounding, but the zipped binary fits on a handful of floppies.