Re: 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;
[download]

:-) Autark

Comment on Re: List processing performance Download Code

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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` [download] A couple characters shorter, plus it's faster because the sort is done after you've filtered out duplicates and common words.	[reply] [d/l]
(chromatic) RE: RE: Re: List processing performance by chromatic (Archbishop) on Jul 11, 2000 at 23:32 UTC
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.	[reply] [d/l]
RE: (chromatic) RE: RE: Re: List processing performance by btrott (Parson) on Jul 12, 2000 at 07:08 UTC
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).	[reply]


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