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Re: need regular expression

by ioannis (Prior)
on Nov 02, 2005 at 08:23 UTC ( #504866=note: print w/replies, xml ) Need Help??


in reply to need regular expression

for ( my @dates = qw( 4-10-31 14-11-31 ) ) { s/ ^ (\d) (\d)? (-\d{1,2}-\d{1,2}) $ /($2?"20$1":"200").$1.$+/ex and print; }

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Re^2: need regular expression
by ioannis (Prior) on Nov 02, 2005 at 10:55 UTC
    This formula is simpler than the one earlier. The main insight here is to avoid strings; it is better to use arithmetic addition to construct the 'year' string (i.e. 20xx) .
    for ( my @dates = qw( 4-10-31 14-11-31 ) ) { s/ ^ (\d{1,2}) ((?:-\d{1,2}){2}) $ /(2000+$1).$+/xe and print; }
      I prefer to use strings - in that case, it becomes easy to deal with 3 or 4 digit years as well:
      my @dates = qw /4-10-31 14-11-31 1979-10-10/; for (@dates) { s/(\d+)/substr("2000", 0, -length($1)).$1/e; print "$_\n"; } __END__ 2004-10-31 2014-11-31 1979-10-10
      Perl --((8:>*

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[Corion]: ... gets called once. The data structure for that is just a hash of arrays, mapping the event type to a queue of registered one-shots, and the first one-shot from the queue gets removed and called.
[Corion]: But now I want to register a one-shot for two events, of which only one will arrive, so my data structure doesn't work anymore...
[Lady_Aleena]: Corion, ouchy.
[Corion]: (maybe I should write this up as a SoPW) - currently, the "most efficient" data structure I come up with is a single array which I scan for the first fitting one-shot. Not efficient but I don't expect more than five outstanding one-shots anyway
[choroba]: can't you create a meta-key corresponding to the disjunction of the events?
[robby_dobby]: Corion: Heh. This whole thing smells of Strategy Pattern or MVC pattern.
[Corion]: And performance linear to the number of registered one-shots doesn't feel that bad. Maybe I should collect statistics on how many callbacks are outstanding ;)
[Corion]: choroba: Yes, but the longer I thought about efficient hashes mapping the event type back to their callbacks, and how to keep them in sync, the more I thought that all that optimization might just not be worth it, even if it's horribly inelegant
[Lady_Aleena]: My biggest problem with hashes at the moment is one with 2,501 keys.
[choroba]: how many event types are there?

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