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Postings from February 2013
On 15 December 2012 20:40, James E Keenan via RT <perlbug-followup@perl.org> wrote: > On Sat Dec 15 05:29:48 2012, sprout wrote: >> On Fri Dec 14 19:03:21 2012, jkeenan wrote: >> > Here is a patch for the regression test part of the solution. Please >> > review. >> >> Thank you. That looks good to me. >> > > Patch applied in cd346b2859236d69de687d1baa46c23e19af2202. > > We still need the fix for the problem. > > Note that some of the tests added were TODO-ed. This may need > mentioning in pod/perldelta.pod if the underlying problem is not fixed > before the upcoming release. I just pushed a patch sequence to get this fixed. My working copy is at yves/revert_skipwhite, and I am smoking it at smoke-me/yves-revert_skipwhite. It is mostly a revert of 5255171e6cd0accee6f76ea2980e32b3b5b8e171. I think FC's patch had some merit BTW, just didnt work out in the game of Jenga that is perl. We maybe will have to reopen RT# 94490 if it is merged. It depends how you look at things. The root of this patch sequence is the fact that: split 0 || " ", $thing; #1 and my $x=0; split $x || " ", $thing; #2 behave differently. The former behaves like: split " ", $thing; #3 and the latter behaves like split / /, $thing; #4 The patch that caused all these problems made #1 behave the same as #2 and #4, instead of its current behavior like #3. Now, besides from the breakage in this ticket I personally think that #2 should behave like #3, which means that the behavior of #1 is just fine. Anyway, its an interesting question, and I could not find an easy way to make split $x || " " behave like split " " when $x is false. The "special" behavior of #3 (called RXf_SKIPWHITE) is triggered only when the pattern can be compile time determined. So far I don't understand the optree logic involved to figure out how to make it work like I expect. An unrelated follow up for this patch sequence might be to look into RXf_SPLIT and RXf_WHITE and RXf_SKIPWHITE. We use more bits than we need. RXf_SKIPWHITE is only relevant when RXf_SPLIT is set, and both RXf_WHITE and RXf_SKIPWHITE are used only in pp_split(). RXf_SPLIT is set only when dealing with a split "..", $thing and not when dealing with split /../, $thing. (IOW it is badly named, it should be called RXf_SKIPWHITE_ALLOWED or something like that.) Simplifying this mess, and putting some or all of these flags somewhere else, might free up some RXf_ bits (which are scarce). Yves -- perl -Mre=debug -e "/just|another|perl|hacker/"Thread Previous | Thread Next