enough theory, now practical code:
use strict;
use warnings;
use Data::Dump qw/pp/;
use Scalar::Util qw/reftype/;
sub walk {
my ($entry,$code) =@_;
my $type = reftype($entry);
$type //= "SCALAR";
if ($type eq "HASH") {
walk($_,$code) for values %$entry;
}
elsif ($type eq "ARRAY") {
walk($_,$code) for @$entry;
}
elsif ($type eq "SCALAR" ) {
$code->($_[0]); # alias of entry
}
else {
warn "unknown type $type";
}
}
my $test = { a => [2, 3, [4, { b => 42 }]], c => 5 };
pp $test;
walk $test, sub { $_[0]+=100 };
pp $test;
Output
/usr/bin/perl -w /tmp/walker.pl
{ a => [2, 3, [4, { b => 42 }]], c => 5 }
{ a => [102, 103, [104, { b => 142 }]], c => 105 }
Cheers Rolf
( addicted to the Perl Programming Language)
UPDATE
of course you could extend walk to call optional $coderefs on every node and specify them as named parameters:
walk $ref , SCALAR => sub { print $_[0] } , ARRAY => sub { Dump $_[0] }, ...
But I think the original code is so small thats its easier to copy and manipulate it in place for different needs.
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