I think this is more along the lines of what i should have (but i
still don't have it working):
On Sun, Nov 10, 2013 at 6:10 PM, shawn wilson <ag4ve...@gmail.com> wrote:
> I'm having a bit of trouble writing a trace array for a structure
> traversal function.
>
> Before someone points out Data::Walker and the like, here is my
> limitation: this is for a script to generate iptables / ipset save
> files - it needs to run on machines with perl 5.10+ without needing
> anything else (including MakeMaker - nothing - just runs out of the
> box). So, if a module isn't in core, I can't really use it.
>
> Nevermind the function name 'flatten' - I just want to get $path to
> work correctly.
>
> Thanks
>
>
> #!/usr/bin/env perl
>
> use strict;
> use warnings;
>
> use Data::Dumper;
>
> my $deep = {
> 'foo' => [qw/
> ugh
> umm
> arr
> /],
> 'bar' => [qw/
> aaa
> bbb
> ccc
> /],
> 'baz' => [
> 'fi' => [qw/
> one
> two
> three
> /],
> 'fo' => [qw/
> four
> five
> six
> /],
> 'fum' => [qw/
> seven
> eight
> nine
> /],
> ],
> };
>
> my ($new) = into_me($deep, undef, 'flatten_els');
>
> print Dumper($new);
>
> sub flatten_els
> {
> my ($var, @etc) = @_;
> my ($path, $type) = @etc;
>
> print "path [" . join('] [', @$path) . "]\n";
>
> return $var, @etc unless ($type =~ /^H /);
>
> $var = join(' ', values %$var);
>
> return $var, @etc;
> }
>
>
>
> # Traverse a variable with callbacks
> sub into_me
> {
> my ($vals, $kfunc, $vfunc, @etc) = @_;
> no strict 'refs';
>
> # This should be private - you probably shouldn't call into_me with a path
> my $path;
> if (scalar(@etc) >= 1 and ref($etc[-1]) eq 'ARRAY' and $etc[-1]->[0]
> eq 'BASE')
> {
> $path = pop @etc;
> }
> else
> {
> push @$path, 'BASE';
> }
>
> my $rtype = (ref(\$vals) eq 'SCALAR' ? 'SCALAR' : ref($vals));
>
> my $ret;
>
> if ($rtype eq 'ARRAY')
> {
push @$path, 'A ';
for my $num (0 .. $#$vals)
{
next unless (defined($vals->[$num]));
my $val = $vals->[$num];
my ($anum, $aval);
($anum, @etc) = $kfunc->($num, @etc, 'EL') if (defined($kfunc));
$anum //= $num;
$path->[-1] =~ s/^A .*/A $anum/;
push @etc, $path;
($aval, @etc) = $vfunc->($val, @etc, 'VAL') if (defined($vfunc));
$aval //= $val;
($ret->[$anum], @etc) = into_me($aval, $kfunc, $vfunc, @etc);
> }
> }
> elsif ($rtype eq 'HASH')
> {
push @$path, 'H ';
foreach my $key (keys %$vals)
{
next unless (defined($vals->{$key}));
my $val = $vals->{$key};
my ($akey, $aval);
($akey, @etc) = $kfunc->($key, @etc, 'KEY') if (defined($kfunc));
$akey //= $key;
$path->[-1] =~ s/^H .*/H $akey/;
push @etc, $path;
($aval, @etc) = $vfunc->($val, @etc, 'VAL') if (defined($vfunc));
$aval //= $val;
($ret->{$akey}, @etc) = into_me($aval, $kfunc, $vfunc, @etc);
> }
> }
> elsif ($rtype eq 'SCALAR')
> {
> push @$path, "S $vals";
> push @etc, $path;
> ($ret, @etc) = $vfunc->($vals, @etc);
> pop @$path;
> }
> else
> {
> $ret = $vals;
> }
>
pop @$path;
> push @etc, $path;
>
> use strict 'refs';
> return $ret, @etc;
> }
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