but clearly a difference between the versions

Specifically, a difference in the program into which the regex is compiled. As you mentioned, the difference is that the latter is more efficient to execute. It's slower to compile, though.

Don't suppose the optimized regex gets stored anywhere accessible?

What? What is it you want?

In reply to Re^3: Optimization of Regexes by ikegami
in thread Optimization of Regexes by shadowSage

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