http://www.perlmonks.org?node_id=1031287


in reply to Re: Manipulate deepest values in complex hash structures
in thread Manipulate deepest values in complex hash structures

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.