Re^2: Trying to optimize de-referenced hash slice without scope variables...

Fellow boriz
Thank you very much for your suggestion, but I'm not sure if

perl -MData::Dumper -e "print Dumper @{$_[3]}{'a','b','c','d'}, $_[3];
+ "
$VAR1 = undef;
$VAR2 = undef;
$VAR3 = undef;
$VAR4 = undef;
$VAR1 = undef;
$VAR2 = undef;
$VAR3 = undef;
$VAR4 = undef;
$VAR1 = undef;
$VAR2 = undef;
$VAR3 = undef;
$VAR4 = undef;
$VAR5 = '1';
[download]

is the same thing as

perl -MData::Dumper -e 'print Dumper @$data{"a","b","c"}, $data'
$VAR1 = undef;
$VAR2 = undef;
$VAR3 = undef;
$VAR4 = {
          'c' => undef,
          'a' => undef,
          'b' => undef
        };
[download]

or I'm doing something really wrong here, or your data structure definition is not the same as my example. :-) Nice try, anyway.

-- monsieur_champs

Comment on Re^2: Trying to optimize de-referenced hash slice without scope variables... Select or Download Code

Replies are listed 'Best First'.
Re^3: Trying to optimize de-referenced hash slice without scope variables... by Joost (Canon) on Jun 15, 2004 at 17:31 UTC
Your $data and @_ are empty here, so this won't work the same because of autovivication. The number of $VAR variables is different, because you have a .. d in the first and a .. c in the second expample. All of this should work if you actually fill $data and `$_[3]` with a hash reference that uses those keys. "What should it profit a man, if he should win a flame war, yet lose his cool?"	[reply] [d/l]
Re^4: Trying to optimize de-referenced hash slice without scope variables... by monsieur_champs (Curate) on Jun 15, 2004 at 17:56 UTC
Autovivification shouldn't fill in the data structure as I access it? So both the accesses should produce the same data structures (that's autovivification work, I guess), and Data::Dumper should produce the same result in both cases. BTW, here is the result, again: `perl -MData::Dumper $data = { a=>'b', c=>'d', e=>'h', i=>'j' }; $_[3] = { a=>'b', c=>'d', e=>'h', i=>'j' }; print Dumper @$data{'a','c','e'}; print "\n"; print Dumper @{$_[3]}{'a','c','e'}; print "\n";` [download] and the result was: `$VAR1 = 'b'; $VAR2 = 'd'; $VAR3 = 'h'; $VAR1 = 'b'; $VAR2 = 'd'; $VAR3 = 'h';` [download] exactly as expected. I'm confused. What's the problem with auto-vivification? Its supposed to fill in the "gore details", it isn't? Thank you for your time and patience! -- monsieur_champs	[reply] [d/l] [select]
Re^3: Trying to optimize de-referenced hash slice without scope variables... by borisz (Canon) on Jun 15, 2004 at 17:37 UTC
My perl works this way, Im sure there is another mistake. `#!/usr/bin/perl use Data::Dumper; %xx = ( a => 1, b => 2 ); sub inputBox{ @{$_[3]}{'a','b','c','d'}; } sub inputBox2{ my $data = $_[3]; @$data{'a','b','c','d'}; } print Dumper (inputBox( 1,2,3,\%xx)); print Dumper (inputBox2( 1,2,3,\%xx));` [download] Boris	[reply] [d/l]