On 27 September 2015 at 18:11, Bart Schaefer > It'll get worse if there are partial matches, e.g., if you had 30000 > repetitions of "wfei" and scanned for "wfeiwj" there'd be a whole lot > of backtracking. There are no "w" anywhere in your sample $str so > each of the comparisons is only one equality test. It's still instant fast for 30k of wfei (attached is the script). I also tried generating a [wfeiwj]-only string, and it's also fast: cat /dev/urandom | env LC_CTYPE=C tr -cd 'wfeiwj' | head -c 120000 > input Gave it one more try with "wfeiwjwoiejfowiejfowijefoiwjefoiwjefoijwoeifjwoiejf" (30k of it, and was searching for it) and it becomes slower (times 0.15s instead of 0.012s) but is still instant fast. > > Still I think the biggest issue is that unmetafication happening too > low down. Since pattry*() is being called repeatedly with the same two > first arguments (prog and string) it might be possible to cache the > unmetafied string after the first call. I wonder why it depends on Zsh version and/or environment (OS, etc.). This doesn't seem related to unmetafication, unless it was changed after 5.0.2. Best regards, Sebastian Gniazdowski