Re: map and grep syntax question

I'm as big a fan of grep and map as the next guy, but sometimes they just don't make sense. In this case, I think a plain for loop would be clearer:

my $parts = [ 'Part1', 'Part2','Part3' ];
my $newLoop;

for (@$parts) {
  my $hash = { PARTNAME => $_ };

  $hash->{SELECTED}++
      if $_ eq $row->{title};

  push @$newLoop, $hash;
}
[download]

Or, if anything, just a single map call, but this demonstrates why I prefer the for loop:

my $parts = [ 'Part1', 'Part2','Part3' ];
my $newLoop = [ map {{ PARTNAME => $_,
                        $_ eq $row->{title}
                           ? (SELECTED => 1)
                           : ()
                    }} @$parts ];
[download]

Update: Joost beat me to the punch on the single-map part, but I still prefer my first snippet.

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Re^2: map and grep syntax question by Joost (Canon) on Dec 10, 2004 at 22:06 UTC
Update: Joost beat me to the punch on the single-map part, but I still prefer my first snippet. I prefer your first snipped too :-) map can get too complicated. my example is probably on the edge of where I would consider using it. "What should it profit a man, if he should win a flame war, yet lose his cool?"	[reply]
Re^2: map and grep syntax question by geektron (Curate) on Dec 10, 2004 at 22:46 UTC
the straight `map` loop is the most concise, i think, plus i need to work more with some of the added list ops. i just want to extend my working knowledge of everything.	[reply] [d/l]
Re^3: map and grep syntax question by revdiablo (Prior) on Dec 10, 2004 at 23:17 UTC
the straight map loop is the most concise, i think The most concise solution is not always the best. Take a look at any Perl Golf contest for conclusive proof of this. :-) For example, here's another concise version: `my $newLoop; push @{$newLoop},{PARTNAME=>$_,/$row->{title}/?(SELECTED=>1):()} for qw(Part1 Part2 Part3);` [download] But if I saw that in real code, I wouldn't be very happy. plus i need to work more with some of the added list ops. i just want to extend my working knowledge of everything. That's fine, but part of learning how to work with something is learning when not to use it. I can't say the map verion that Joost and I both came up with is the worst code I've seen, but it isn't particularly clear. So, learn how to use map, but also learn when to use something else.	[reply] [d/l]