Below is a test file for pcre2test which shows matching times which I
cannot explain. I run it on Windows like this:
pcre2test -tm 1 tests.txt
If I understand this correctly, at least the atomic grouping pattern
should run fast:
https://www.regular-expressions.info/catastrophic.html
Interestingly, with JIT all patterns run instantly in 0 ms:
pcre2test -jit -tm 1 tests.txt
I am using PCRE2 SVN 1284.
Could anyone jump in with an explanation?
Many thanks,
Ralf
----------
# Match is instantaneous (0 milliseconds).
/aa.*?bb/
\[aa bb ]{200}
# Failure with extra letter "x" is also extremely fast (0 milliseconds).
/aa.*?bbx/
\[aa bb ]{200}
# Failure with extra letter "y" is just as fast (0 milliseconds).
/aa.*?bby/
\[aa bb ]{200}
# Failure with extra letter "a" is very slow (> 6000 ms).
/aa.*?bba/
\[aa bb ]{200}
# Failure with extra letter "b" is also very slow (> 6000 ms).
/aa.*?bbb/
\[aa bb ]{200}
# Atomic grouping does not help (each > 6000 ms).
/aa(?>.*?bba)/
\[aa bb ]{200}
/aa(?>.*?bbb)/
\[aa bb ]{200}
# Is this expected behavior? Suggestions? Thank you!
