#!/usr/bin/perl -w use strict; use warnings; use feature 'state'; use Data::Dumper; $Data::Dumper::Deparse=1; our %data; our $VAR1; sub insert { my ($name,$href)=@_; $href->{$name}=$href->{'nextID'}->(); print $name," => ",$href->{$name},"\n"; } sub init_data { %data=( nextID => sub { state $n=100; $n++; print "\$n is now $n\n"; return $n; } ); } init_data(); print "Working with the original:\n\n"; insert(a => \%data); insert(b => \%data); insert(c => \%data); my $dump=Dumper(\%data); print "\nData::Dumper output:\n\n"; print "$dump\n"; print "\nWorking with the original again:\n\n"; insert(d => \%data); print "\nWorking with the re-evaluated Data::Dumper output:\n\n"; eval $dump; die $@ if $@; insert(d => $VAR1); #### Working with the original: $n is now 101 a => 101 $n is now 102 b => 102 $n is now 103 c => 103 Data::Dumper output: $VAR1 = { 'c' => 103, 'a' => 101, 'nextID' => sub { use warnings; use strict; use feature 'state'; state $n = 100; ++$n; print "\$n is now $n\n"; return $n; }, 'b' => 102 }; Working with the original again: $n is now 104 d => 104 Working with the re-evaluated Data::Dumper output: $n is now 101 d => 101 #### #!/usr/bin/perl -w use strict; use warnings; use Data::Dumper; $Data::Dumper::Deparse=1; our %data; our $VAR1; sub insert { my ($name,$href)=@_; $href->{$name}=$href->{'nextID'}->(); print $name," => ",$href->{$name},"\n"; } sub init_data { my $n=100; %data=( nextID => sub { $n++; print "\$n is now $n\n"; return $n; } ); } init_data(); print "Working with the original:\n\n"; insert(a => \%data); insert(b => \%data); insert(c => \%data); my $dump=Dumper(\%data); print "\nData::Dumper output:\n\n"; print "$dump\n"; print "\nWorking with the original again:\n\n"; insert(d => \%data); print "\nWorking with the re-evaluated Data::Dumper output:\n\n"; eval $dump; die $@ if $@; insert(d => $VAR1); #### Working with the original: $n is now 101 a => 101 $n is now 102 b => 102 $n is now 103 c => 103 Data::Dumper output: $VAR1 = { 'c' => 103, 'b' => 102, 'a' => 101, 'nextID' => sub { use warnings; use strict; ++$n; print "\$n is now $n\n"; return $n; } }; Working with the original again: $n is now 104 d => 104 Working with the re-evaluated Data::Dumper output: Global symbol "$n" requires explicit package name at (eval 8) line 8. Global symbol "$n" requires explicit package name at (eval 8) line 9. Global symbol "$n" requires explicit package name at (eval 8) line 10. #### #!/usr/bin/perl -w use Data::Dumper; $Data::Dumper::Deparse=1; our %data; our $VAR1; sub insert { my ($name,$href)=@_; $href->{$name}=$href->{'nextID'}->(); print $name," => ",$href->{$name},"\n"; } sub init_data { my $n=100; %data=( nextID => sub { $n++; print "\$n is now $n\n"; return $n; } ); } init_data(); print "Working with the original:\n\n"; insert(a => \%data); insert(b => \%data); insert(c => \%data); my $dump=Dumper(\%data); print "\nData::Dumper output:\n\n"; print "$dump\n"; print "\nWorking with the original again:\n\n"; insert(d => \%data); print "\nWorking with the re-evaluated Data::Dumper output:\n\n"; eval $dump; die $@ if $@; insert(d => $VAR1); #### Working with the original: $n is now 101 a => 101 $n is now 102 b => 102 $n is now 103 c => 103 Data::Dumper output: $VAR1 = { 'a' => 101, 'c' => 103, 'nextID' => sub { ++$n; print "\$n is now $n\n"; return $n; }, 'b' => 102 }; Working with the original again: $n is now 104 d => 104 Working with the re-evaluated Data::Dumper output: $n is now 1 d => 1