in reply to Re: List processing performance
in thread List processing performance

playing golf, 
my @words  = ( ... );
my @common = qw|a and at|;

my %seen;
@seen{@common} = (1) x @common;
@words = grep { $_ = lc; ! $seen{$_}++ } sort @words;

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:-) Autark

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RE: Re: List processing performance
by btrott (Parson) on Jul 11, 2000 at 20:52 UTC
    Oh, is *that* what we're doing then. :) In which case replace your last line with this: 
        @words = sort grep !$seen{$_ = lc}++, @words

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    A couple characters shorter, plus it's faster because the sort is done after you've filtered out duplicates and common words.
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[d/l]
      Golf, eh? @words = sort grep !$seen{+lc}++, @words; The + keeps lc from being interpreted as a hash key, and lc operates on $_ by default.

      Update: Of course, this works if your data set is all lowercase. Moral of the story, don't go for the birdie unless you're sure it's what you want.

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[d/l]
        Yes, but it doesn't work properly, because you're not actually changing $_. And if you don't change $_, then the words don't get lower-cased, and your sort is off (because it'll sort upper-case before lower-case).
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