Heap::Elem::RefRev - Reversed Object Reverence Heap Elements


Heap documentation Contained in the Heap distribution.

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NAME

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Heap::Elem::RefRev - Reversed Object Reverence Heap Elements

SYNOPSIS

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  use Heap::Elem::RefRev( RefRElem );
  use Heap::Fibonacci;

  my $heap = Heap::Fibonacci->new;
  my $elem;

  foreach $i ( 1..100 ) {
      $obj = myObject->new( $i );
      $elem = RefRElem( $obj );
      $heap->add( $elem );
  }

  while( defined( $elem = $heap->extract_top ) ) {
      # assume that myObject object have a method I<printable>
      print "Largest is ", $elem->val->printable, "\n";
  }

DESCRIPTION

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Heap::Elem::RefRev is used to wrap object reference values into an element that can be managed on a heap. Each referenced object must have a method cmp which can compare itself with any of the other objects that have references on the same heap. These comparisons must be consistant with normal arithmetic. The top of the heap will have the largest (according to cmp) element still remaining. (See Heap::Elem::Ref if you want the heap to always return the smallest element.)

The details of the Elem interface are described in Heap::Elem.

The details of using a Heap interface are described in Heap.

AUTHOR

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John Macdonald, john@perlwolf.com

COPYRIGHT

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SEE ALSO

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Heap(3), Heap::Elem(3), Heap::Elem::Ref(3).


Heap documentation Contained in the Heap distribution.

package Heap::Elem::RefRev;

use strict;
use vars qw($VERSION @ISA @EXPORT @EXPORT_OK);
use Heap::Elem;

require Exporter;

@ISA = qw(Exporter Heap::Elem);

# No names exported.
@EXPORT = ( );

# Available for export: RefRElem (to allocate a new Heap::Elem::RefRev value)
@EXPORT_OK = qw( RefRElem );

$VERSION = '0.80';

sub RefRElem {	# exportable synonym for new
    Heap::Elem::RefRev->new(@_);
}

# compare two RefRev elems - the objects must have a compatible cmp method
sub cmp {
    return $_[1][0]->cmp( $_[0][0] );
}

1;
__END__