1# $Id: Number.pm,v 1.14 2002/12/26 17:57:09 matt Exp $
2
3package XML::XPath::Number;
4use XML::XPath::Boolean;
5use XML::XPath::Literal;
6use strict;
7
8use overload
9        '""' => \&value,
10        '0+' => \&value,
11        '<=>' => \&cmp;
12
13sub new {
14    my $class = shift;
15    my $number = shift;
16    if ($number !~ /^\s*[+-]?(\d+(\.\d*)?|\.\d+)\s*$/) {
17        $number = undef;
18    }
19    else {
20        $number =~ s/^\s*(.*)\s*$/$1/;
21    }
22    bless \$number, $class;
23}
24
25sub as_string {
26    my $self = shift;
27    defined $$self ? $$self : 'NaN';
28}
29
30sub as_xml {
31    my $self = shift;
32    return "<Number>" . (defined($$self) ? $$self : 'NaN') . "</Number>\n";
33}
34
35sub value {
36    my $self = shift;
37    $$self;
38}
39
40sub cmp {
41    my $self = shift;
42    my ($other, $swap) = @_;
43    if ($swap) {
44        return $other <=> $$self;
45    }
46    return $$self <=> $other;
47}
48
49sub evaluate {
50    my $self = shift;
51    $self;
52}
53
54sub to_boolean {
55    my $self = shift;
56    return $$self ? XML::XPath::Boolean->True : XML::XPath::Boolean->False;
57}
58
59sub to_literal { XML::XPath::Literal->new($_[0]->as_string); }
60sub to_number { $_[0]; }
61
62sub string_value { return $_[0]->value }
63
641;
65__END__
66
67=head1 NAME
68
69XML::XPath::Number - Simple numeric values.
70
71=head1 DESCRIPTION
72
73This class holds simple numeric values. It doesn't support -0, +/- Infinity,
74or NaN, as the XPath spec says it should, but I'm not hurting anyone I don't think.
75
76=head1 API
77
78=head2 new($num)
79
80Creates a new XML::XPath::Number object, with the value in $num. Does some
81rudimentary numeric checking on $num to ensure it actually is a number.
82
83=head2 value()
84
85Also as overloaded stringification. Returns the numeric value held.
86
87=cut
88