Data::Range::Compare::Cookbook::Instance_and_Constants - Look inside the instance
package a_to_z; use strict; use warnings; use vars qw(@ISA @list %ids %helper); use Data::Range::Compare qw(:KEYS); @ISA=qw(Data::Range::Compare); use constant key_ids=>6; @list=('a' .. 'z'); my $id=-1; %ids=map { ($_,++$id) } @list; undef $id; $helper{add_one}=\&add_one; sub add_one { my $here=$ids{$_[0]}; ++$here; return 'z' if $#list<$here; $list[$here] } $helper{sub_one}=\&sub_one; sub sub_one { my $here=$ids{$_[0]}; --$here; return 'a' if $here<0; $list[$here] } sub cmp_values { $_[0] cmp $_[1] } $helper{cmp_values}=\&cmp_values; sub new{ my ($class,$start,$end,$generated,$missing)=@_; my $s=$class->SUPER::new(\%helper,$start,$end,$generated,$missing); $s->[key_ids]=\%ids; $s; } sub letter_ids { %{$_[0]->[key_ids]} } sub range_compare { my ($s,@args)=@_; $s->SUPER::range_compare(\%helper,@args) } sub get_common_range { my ($class,@args)=@_; $class->SUPER::get_common_range(\%helper,@args); } sub first_letter () { $_[0]->[key_start] } sub last_letter () { $_[0]->[key_end] } 1;
Now you can create a perl script to load a_to_z and use the simplified functionality.
use a_to_z; my $obj_a=a_to_z->new(qw(c f)); my $obj_b=a_to_z->new(qw(a z)); my $obj_c=a_to_z->new(qw(g j)); $list=[ [$obj_a] ,[$obj_b] ,[$obj_c] ]; $sub=a_to_z->range_compare($list); while(my @row=$sub->()) { my ($obj_a,$obj_b,$obj_c)=@row; my $common_range=a_to_z-->get_common_range(\@row); print "\n"; print "Common Range: $common_range\n"; my ($obj_a,$obj_b,$obj_c)=@row; my $range_a_state=$obj_a->missing ? 'Not in set a' : 'in set a'; my $range_b_state=$obj_b->missing ? 'Not in set b' : 'in set b'; my $range_c_state=$obj_c->missing ? 'Not in set c' : 'in set c'; print "Range_a: $obj_a is $range_a_state\n"; print "Range_b: $obj_b is $range_b_state\n"; print "Range_c: $obj_c is $range_c_state\n"; } Output: Common Range: a - b Range_a: a - b is Not in set a Range_b: a - z is in set b Range_c: a - f is Not in set c Common Range: c - f Range_a: c - f is in set a Range_b: a - z is in set b Range_c: a - f is Not in set c Common Range: g - j Range_a: g - z is Not in set a Range_b: a - z is in set b Range_c: g - j is in set c Common Range: k - z Range_a: g - z is Not in set a Range_b: a - z is in set b Range_c: k - z is Not in set c
Simple example demonstrating HOWTO subclass the "a to z" example
Data::Range::Compare instances are array references and use numeric entries to identify each element.
key_helper
This constant represents the position of \%helper in the array instance.
The value of key_helper is 0
key_start
This constant represents the position of $start in this instance.
The value of key_start is 1
key_end
This constant represents the position of $end in this instance.
The value of key_end is 2
key_generated
This constant represents the position of $generated in this instance.
The value of key_generated is 3
key_missing
This constant represents the position of $missing in this instance.
The value of key_missing is 4
key_key_data
This constant represents the position of $key_data in this instance.
The value of key_key_data is 5
Michael Shipper
Copyright 2010 Michael Shipper. All rights reserved.
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
Data::Range::Compare::Cookbook perlboot
To install Data::Range::Compare, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Data::Range::Compare
CPAN shell
perl -MCPAN -e shell install Data::Range::Compare
For more information on module installation, please visit the detailed CPAN module installation guide.