Re^4: Inexplicably slow regex

[Anonymous Monk]

You may wish to show your actual regex, as that's the likely source of the issue.

[Anonymous Monk]

The actual regular expressions start exactly as above but require additional matching text at the end. Before posting I retested my input against the example regular expressions and encountered the same performance problems so the examples should be enough for analysis.

I'm sure providing my rather large input file would have helped but that would be difficult to manage. Luckily the user Grandfather below provided a self contained working example that illustrates the problem.