Author: ND Date: To: Pcre-dev Subject: [pcre-dev] Influence of some start-up optimizations at the
beginning of the pattern
Good day!
pcre2api.html document:
There are also other start-up optimizations. For example, a minimum length
for the subject may be recorded. Consider the pattern
(*MARK:A)(X|Y)
The minimum length for a match is one character. If the subject is "ABC",
there will be attempts to match "ABC", "BC", and "C". An attempt to match
an empty string at the end of the subject does not take place, because
PCRE2 knows that the subject is now too short, and so the (*MARK) is never
encountered. In this case, the optimization does not affect the overall
match result, which is still "no match", but it does affect the auxiliary
information that is returned.
But it seems no difference in pcre2test output in normal and
no_start_optimize cases. Both returned mark value:
PCRE2 version 10.33 2019-04-16
/(*MARK:A)(X|Y)/mark
ABC
No match, mark = A
/(*MARK:A)(X|Y)/mark,no_start_optimize
ABC
No match, mark = A
Tell please about what information are words "it does affect the auxiliary
information that is returned "?
May be some correction to docs needed?
