Author image Michael Shipper
and 1 contributors


Data::Range::Compare::Stream::CallBack - Dynamic compare support plugin


  use Data::Range::Compare::Stream::CallBack qw(%HELPER);

  # create the factory instance we will hand around
  my $factory_instance=new Data::Range::Compare::Stream::CallBack(\%HELPER);


This module module provides a dynamic method of supporting diffrent data types without the need to subclass Data::Range::Compare::Stream. Note: this class does in fact subclass Data::Range::Compare::Stream.


%HELPER is exported by default.

%HELPER is a hash that contains 3 anonymous functions.

  our %HELPER=(
    sub_one=>sub { $_[0] - 1 },
    add_one=>sub { $_[0] + 1 },
    cmp_values=>sub { $_[0] <=> $_[1] },

OO Methods

This section covers the OO Methods in the package.

  • my $range=new Data::Range::Compare::Stream::CallBack(\%HELPER,$range_start,$range_end);

  • my $range=new Data::Range::Compare::Stream::CallBack(\%HELPER$range_start,$range_end,$data);

  • my $factory_instance=new Data::Range::Compare::Stream::CallBack(\%HELPER);

    Object constructor: Creates a new instance of Data::Range::Compare::Stream.

    Arguments an their meanings:

      \%HELPER  -- Required.
        This hash ref use used to handle comparison, addition and subtraction
      $range_start -- Required
        Represents the start of this given range
      $range_end -- Required
        Represents the end of this range.
      $data -- Optional
        Used to tag this range with your data
  • my $new_value=$range->sub_one($value);

    Computes and returns the object that came before this $value. This function uses the helper->{sub_one} code ref to handle the call.

  • my $new_value=$range->add_one($value)

    Computes and returns the object that comes after this $value. This function uses the $helper->{add_one} code ref to handle the call.

  • my $cmp=$range->cmp_values($value_a,$value_b)

    Returns -1,0,1 similar to <=> or cmp. This function uses the $helper->{cmp_values} code ref to handle the call.

  • my $range=$factory_instance->factory(0,1);

  • my $range=$factory_instance->factory(0,1,$data);

    Given an instance of Data::Range::Compare::Stream::CallBack, this function is used to create a new range object that will also contain the related %HELPER function.




Michael Shipper

Source-Forge Project

As of version 0.001 the Project has been moved to

Data Range Compare


Copyright 2011 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.