Commit | Line | Data |
---|---|---|
86530b38 AT |
1 | package Heap::Elem::NumRev; |
2 | ||
3 | use strict; | |
4 | use vars qw($VERSION @ISA @EXPORT @EXPORT_OK); | |
5 | ||
6 | require Exporter; | |
7 | require AutoLoader; | |
8 | ||
9 | @ISA = qw(Exporter AutoLoader); | |
10 | ||
11 | # No names exported. | |
12 | @EXPORT = ( ); | |
13 | ||
14 | # Available for export: NumRElem (to allocate a new Heap::Elem::NumRev value) | |
15 | @EXPORT_OK = qw( NumRElem ); | |
16 | ||
17 | $VERSION = '0.70'; | |
18 | ||
19 | ||
20 | # Preloaded methods go here. | |
21 | ||
22 | sub new { | |
23 | my $class = shift; | |
24 | $class = ref($class) || $class; | |
25 | ||
26 | # two slot array, 0 for the numeric value, 1 for use by Heap | |
27 | my $self = [ shift, undef ]; | |
28 | ||
29 | return bless $self, $class; | |
30 | } | |
31 | ||
32 | sub NumRElem { # exportable synonym for new | |
33 | Heap::Elem::NumRev->new(@_); | |
34 | } | |
35 | ||
36 | # get or set value slot | |
37 | sub val { | |
38 | my $self = shift; | |
39 | @_ ? ($self->[0] = shift) : $self->[0]; | |
40 | } | |
41 | ||
42 | # get or set heap slot | |
43 | sub heap { | |
44 | my $self = shift; | |
45 | @_ ? ($self->[1] = shift) : $self->[1]; | |
46 | } | |
47 | ||
48 | # compare two NumR elems (reverse order) | |
49 | sub cmp { | |
50 | my $self = shift; | |
51 | my $other = shift; | |
52 | return $other->[0] <=> $self->[0]; | |
53 | } | |
54 | ||
55 | # Autoload methods go after =cut, and are processed by the autosplit program. | |
56 | ||
57 | 1; | |
58 | __END__ | |
59 | # Below is the stub of documentation for your module. You better edit it! | |
60 | ||
61 | =head1 NAME | |
62 | ||
63 | Heap::Elem::NumRev - Perl extension for Reversed Numeric Heap Elements | |
64 | ||
65 | =head1 SYNOPSIS | |
66 | ||
67 | use Heap::Elem::NumRev( NumRElem ); | |
68 | use Heap::Fibonacci; | |
69 | ||
70 | my $heap = Heap::Fibonacci->new; | |
71 | my $elem; | |
72 | ||
73 | foreach $i ( 1..100 ) { | |
74 | $elem = NumRElem( $i ); | |
75 | $heap->add( $elem ); | |
76 | } | |
77 | ||
78 | while( defined( $elem = $heap->extract_top ) ) { | |
79 | print "Largest is ", $elem->val, "\n"; | |
80 | } | |
81 | ||
82 | =head1 DESCRIPTION | |
83 | ||
84 | Heap::Elem::NumRev is used to wrap numeric values into an element | |
85 | that can be managed on a heap. The top of the heap will have | |
86 | the largest element still remaining. (See L<Heap::Elem::Num> | |
87 | if you want the heap to always return the smallest element.) | |
88 | ||
89 | The details of the Elem interface are described in L<Heap::Elem>. | |
90 | ||
91 | The details of using a Heap interface are described in L<Heap>. | |
92 | ||
93 | =head1 AUTHOR | |
94 | ||
95 | John Macdonald, jmm@perlwolf.com | |
96 | ||
97 | =head1 COPYRIGHT | |
98 | ||
99 | Copyright 1998-2003, O'Reilly & Associates. | |
100 | ||
101 | This code is distributed under the same copyright terms as perl itself. | |
102 | ||
103 | =head1 SEE ALSO | |
104 | ||
105 | Heap(3), Heap::Elem(3), Heap::Elem::Num(3). | |
106 | ||
107 | =cut |