1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
|
package Data::DPath::Filters;
our $AUTHORITY = 'cpan:SCHWIGON';
# ABSTRACT: Magic functions available inside filter conditions
$Data::DPath::Filters::VERSION = '0.60';
use strict;
use warnings;
use Data::Dumper;
use Scalar::Util;
use constant {
HASH => 'HASH',
ARRAY => 'ARRAY',
SCALAR => 'SCALAR',
};
our $idx;
our $p; # current point
sub affe {
return $_ eq 'affe' ? 1 : 0;
}
sub idx { $idx }
sub size()
{
no warnings 'uninitialized';
return -1 unless defined $_;
# speed optimization: first try faster ref, then reftype
# ref
return scalar @$_ if ref $_ eq ARRAY;
return scalar keys %$_ if ref $_ eq HASH;
return 1 if ref \$_ eq SCALAR;
# reftype
return scalar @$_ if Scalar::Util::reftype $_ eq ARRAY;
return scalar keys %$_ if Scalar::Util::reftype $_ eq HASH;
return 1 if Scalar::Util::reftype \$_ eq SCALAR;
# else
return -1;
}
sub key()
{
no warnings 'uninitialized';
my $attrs = defined $p->attrs ? $p->attrs : {};
return $attrs->{key};
}
sub value()
{
no warnings 'uninitialized';
return $_;
}
sub isa($) {
my ($classname) = @_;
no warnings 'uninitialized';
#print STDERR "*** value ", Dumper($_ ? $_ : "UNDEF");
return $_->isa($classname) if Scalar::Util::blessed $_;
return undef;
}
sub reftype() {
return Scalar::Util::reftype($_);
}
sub is_reftype($) {
no warnings 'uninitialized';
return (Scalar::Util::reftype($_) eq shift);
}
1;
=pod
=encoding UTF-8
=head1 NAME
Data::DPath::Filters - Magic functions available inside filter conditions
=head1 API METHODS
=head2 affe
Mysterious test function. Will vanish. Soon. Or will it really? No,
probably not. I like it. :-)
Returns true if the value eq "affe".
=head2 idx
Returns the current index inside array elements.
Please note that the current matching elements might not be in a
defined order if resulting from anything else than arrays.
=head2 size
Returns the size of the current element. If it is an array ref it
returns the number of elements, if it is a hash ref it returns number of keys,
if it is a scalar it returns 1, everything else returns -1.
=head2 key
If it is a hashref returns the key under which the current element is
associated as value. Else it returns undef.
This gives the key() function kind of a "look back" behaviour because
the associated point is already after that key.
=head2 value
Returns the value of the current element.
=head2 isa
Frontend to UNIVERSAL::isa. True if the current element is_a given
class.
=head2 reftype
Frontend to Scalar::Util::reftype.
Returns Scalar::Util::reftype of current element $_. With this you can
do comparison by yourself with C<eq>, C<=~>, C<~~> or whatever in
filter expressions.
=head2 is_reftype($EXPECTED_TYPE)
Frontend to Scalar::Util::reftype.
Checks whether Scalar::Util::reftype of current element $_ equals the
provided argument $EXPECTED_TYPE and returns true/false.
=head1 AUTHOR
Steffen Schwigon <ss5@renormalist.net>
=head1 COPYRIGHT AND LICENSE
This software is copyright (c) 2024 by Steffen Schwigon.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
=cut
__END__
# sub parent, Eltern-Knoten liefern
# nextchild, von parent und mir selbst
# previous child
# "." als aktueller Knoten, kind of "no-op", daran aber Filter verknüpfbar, löst //.[filter] und /.[filter]
# IDEA: functions that return always true, but track stack of values, eg. last taken index
#
# //AAA/*[ _push_idx ]/CCC[ condition ]/../../*[ idx == pop_idx + 1]/
#
# This would take a way down to a filtered CCC, then back again and take the next neighbor.
|
