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Postings from August 2010
On Wed, 04 Aug 2010 22:09:57 -0600, karl williamson <public@khwilliamson.com> wrote: > demerphq wrote: > > On 4 August 2010 15:38, karl williamson <public@khwilliamson.com> wrote: > >> Aristotle Pagaltzis wrote: > >>> * Ben Morrow <ben@morrow.me.uk> [2010-08-01 22:35]: > >>>> My alternative suggestion was to introduce a new grouping > >>>> construct, which I tentatively called (?~sixm:) (I don't much > >>>> like that, but there aren't many alternatives at this point), > >>>> which *does* do what you expect; and use that for > >>>> stringification instead. That way we change the stringification > >>>> once, now, and then never again. > >>> I’m unsure about how good an idea that is. > >>> > >>> Presumably the defaults can change in a future version of Perl, > >>> in which case a stringified pattern that uses this syntax will > >>> mean different things on different Perl versions. In some cases > >>> this will even magically do what you want, but it could equally > >>> be a pitfall. > >> FWIW, I have given this some thought, and came to the conclusion that Perl > >> is almost certainly never going to change the defaults, because of the > >> backward compatibility issues. > > > > Except that its been discussed many times that being able to specify > > the default flags in a lexically scoped manner would be a useful > > feature. So while it might be true that /perl/ will not change the > > default flags, it is quite conceivable that perl will provide the user > > a way to do so. > > Certainly, but it's not relevant here, as this construct would not be > affected by those. (I now think a period is better than an underscore, Assuming that the . is the same as the _ in the other thread, ... No, as it is not a syntax error at the moment: $ perl -we'$a =~ m/foo/i_Cu' Bareword found where operator expected at -e line 1, near "m/foo/i_Cu" syntax error at -e line 1, next token ??? $ perl -we'$a =~ m/foo/i.Cu' Useless use of concatenation (.) or string in void context at -e line 1. Name "main::a" used only once: possible typo at -e line 1. in the bottom example, the . is interpreted as a concatenation. > so will use that in the examples.) (?.:foo) would mean this cluster > does not inherit the surrounding flags, but uses the /perl/ default > ones. (.x:foo) means this cluster does not inherit the surrounding > flags, but uses the /perl/ default ones, but also the x modifier is > selected, whether or not it is a /perl/ default. > > Whatever the user has chosen to be the default, it will be shown in the > stringification iff it differs from the /perl/ default. -- H.Merijn Brand http://tux.nl Perl Monger http://amsterdam.pm.org/ using 5.00307 through 5.12 and porting perl5.13.x on HP-UX 10.20, 11.00, 11.11, 11.23, and 11.31, OpenSuSE 10.3, 11.0, and 11.1, AIX 5.2 and 5.3. http://mirrors.develooper.com/hpux/ http://www.test-smoke.org/ http://qa.perl.org http://www.goldmark.org/jeff/stupid-disclaimers/Thread Previous | Thread Next