Reversing a regular expression and reversing a glob are about the same: you just flip everything around and you're done. In fact RE2 uses this fact to speed up

Reversing a regular expression and reversing a glob are about the same: you just flip everything around and you're done. In fact RE2 uses this fact to speed up regexp searches. See https://swtch.com/~rsc/regexp/regexp3.html#submatch https://swtch.com/~rsc/regexp/regexp3.html#submatch and scan ahead a bit for "Run the DFA backward".