http://www.perlmonks.org?node_id=79092


in reply to sorting based on a list

If you are really going to sort by the first letter only in a special order you might try it with this:
my $sortstr = join('', @list); my @sorted_list = sort { index($sortstr,substr($a,0,1)) <=> index($sortstr,substr($b,0,1)) || $a <=> $b } @list2;
The first will compare the first letter only, the later will compare if the first letter is equal.
--
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Re: Re: sorting based on a list
by ChemBoy (Priest) on May 09, 2001 at 19:05 UTC

    Nice idea--I propose the following modification, to dump extra words at the end (and to use string comparison, of course):

    my $sortstr = join('', @list); my @sorted_list = sort { rindex($sortstr,substr($b,0,1)) <=> rindex($sortstr,substr($a,0,1)) || $a cmp $b } @list2;

    Of course, you might want words that start with letters not in the list to be at the front, in which case, alphie's solution is preferable (aside from using <=> instead of cmp).

    Update: doh! It doesn't do what I thought it did! Fix coming...
    Fix here:

    my $sortstr = join('', @list); my @sorted_list = sort { my ($tmp1,$tmp2); (($tmp1 = index($sortstr,substr($a,0,1))) >= 0 ? $tmp1 : length($sort +str)) <=> (($tmp2 = index($sortstr,substr($b,0,1))) >= 0 ? $tmp2 : length($sort +str)) || $a cmp $b } @list2;



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