Re^3: map weirdness

well, it works in my case..

insaniac][amano: ~ : perl -we 'use strict;my @d=([0,"BE"],[3,"BUS"],[4
+,"BUS2"]);my @a=map($_ , split(/,/, "BUS2,BE") ) ; my @b=map { my $ma
+pkey=$_; map { $d[$mapkey]->[1] =~ /$a[$_]/ ? $d[$mapkey] : () } 0..$
+#a } 0..$#d; use Data::Dumper;print Dumper(@b);'
$VAR1 = [
          0,
          'BE'
        ];
$VAR2 = [
          4,
          'BUS2'
        ];

insaniac][amano: ~ : perl -we 'use strict;my @d=([0,"BE"],[3,"BUS"],[4
+,"BUS2"]);my @a=map($_ , split(/,/, "BUS2,BE") ) ; my @b=map { my $ma
+pkey=$_; map { $d[$mapkey]->[1] =~ /$a[$_]/ ? [@{$d[$mapkey]}] : () }
+ 0..$#a } 0..$#d; use Data::Dumper;print Dumper(@b);'
$VAR1 = [
          0,
          'BE'
        ];
$VAR2 = [
          4,
          'BUS2'
        ];
[download]

--
to ask a question is a moment of shame
to remain ignorant is a lifelong shame

Comment on Re^3: map weirdness Download Code

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Re^4: map weirdness by ysth (Canon) on Dec 13, 2004 at 19:11 UTC
Add @d to the Dumper() call, and you'll see the difference: $ perl -we 'use strict;my @d=([0,"BE"],[3,"BUS"],[4, "BUS2"]);my @a=map($_ , split(/,/, "BUS2,BE") ) ; my @b=map { my $mapk +ey =$_; map { $d[$mapkey]->[1] =~ /$a[$_]/ ? $d[$mapkey] : () } 0..$#a } +0 ..$#d; use Data::Dumper;print Dumper(@d,@b)' $VAR1 = [ 0, 'BE' ]; $VAR2 = [ 3, 'BUS' ]; $VAR3 = [ 4, 'BUS2' ]; $VAR4 = $VAR1; $VAR5 = $VAR3; $ perl -we 'use strict;my @d=([0,"BE"],[3,"BUS"],[4, "BUS2"]);my @a=map($_ , split(/,/, "BUS2,BE") ) ; my @b=map { my $mapk +ey =$_; map { $d[$mapkey]->[1] =~ /$a[$_]/ ? [@{$d[$mapkey]}] : () } 0..$ +#a } 0 ..$#d; use Data::Dumper;print Dumper(@d,@b)' $VAR1 = [ 0, 'BE' ]; $VAR2 = [ 3, 'BUS' ]; $VAR3 = [ 4, 'BUS2' ]; $VAR4 = [ 0, 'BE' ]; $VAR5 = [ 4, 'BUS2' ]; [download] In the second case, @b is composed of refs to new arrays that have copies of the arrays referenced in @d. People often shoot themselves in the foot by leaving shared references like this in datastructures without meaning to. If, instead of 'BUS2' et. al., you had references, forming an even deeper structure, those would still be shared, though. If you need to prevent that, use something like `Storable::dclone($ref)` instead of `[@{$ref}]`.	[reply] [d/l] [select]
Re^5: map weirdness by insaniac (Friar) on Dec 15, 2004 at 15:24 UTC
thanx for your effort and explanation :-D -- to ask a question is a moment of shame to remain ignorant is a lifelong shame	[reply]