Front page | perl.perl5.porters |
Postings from September 2011
On Tue, Sep 27, 2011 at 2:44 PM, Eric Brine <ikegami@adaelis.com> wrote: > On Tue, Sep 27, 2011 at 1:22 AM, Father Chrysostomos via RT < > perlbug-followup@perl.org> wrote: > >> On Mon Sep 26 20:04:14 2011, ikegami@adaelis.com wrote: >> > On Sat, Sep 24, 2011 at 9:41 AM, Father Chrysostomos via RT < >> > perlbug-followup@perl.org> wrote: >> > >> > > On Sun Sep 18 13:33:28 2011, sprout wrote: >> > > > On Mon Sep 12 06:24:25 2011, ph10@hermes.cam.ac.uk wrote: >> > > > > another oddity of (*THEN). >> > > > > >> > > > > Pattern: /a+?(*THEN)c/ >> > > > > Subject: aaac >> > > > > Result: Perl 5.012003 matches "aaac" >> > > > >> > > > That’s strange. In 5.14 it doesn’t match. I don’t know which is >> worse. >> > > >> > >> > According to the 5.14.1 docs, it shouldn't match. >> > >> > Note that if [the (*THEN)] operator is used and NOT inside of an >> >> > alternation then it acts exactly like the (*PRUNE) operator. >> > >> > Consider the pattern A (*PRUNE) B, where A and B are complex patterns. >> Until >> > the (*PRUNE) verb is reached, A may backtrack as necessary to match. >> Once it >> > is reached, matching continues in B, which may also backtrack as >> necessary; >> > however, should B not match, then no further backtracking will take >> place, >> > and the pattern will fail outright at the current starting position. >> >> *at the current starting position* >> > > How can you check at what position it failed? I don't even know what that > means (and this is in our documentation). > Ok, I understand what the docs are *trying* to convery. The docs aren't just unclear, they are self-contradictory. In two places, even! - Failing outright is exactly the opposite the failing for only one start position. - Allowing no further backtracking to take place is the opposite of allowing backtracking to try at a different start position.Thread Previous | Thread Next