1PPIx::Regexp::Node(3) User Contributed Perl DocumentationPPIx::Regexp::Node(3)
2
6 PPIx::Regexp::Node - Represent a container
7
9 use PPIx::Regexp::Dumper;
10 PPIx::Regexp::Dumper->new( 'qr{(foo)}' )->print();
11
13 "PPIx::Regexp::Node" is a PPIx::Regexp::Element.
14 "PPIx::Regexp::Node" is the parent of PPIx::Regexp,
16 PPIx::Regexp::Node::Range and PPIx::Regexp::Structure.
17
19 This class represents a structural element that contains other classes.
20 It is an abstract class, not instantiated by the lexer.
21
23 This class provides the following public methods. Methods not
24 documented here are private, and unsupported in the sense that the
25 author reserves the right to change or remove them without notice.
26 child
28 my $kid = $node->child( 0 );
29 This method returns the child at the given index. The indices start
31 from zero, and negative indices are from the end of the list, so that
32 "$node->child( -1 )" returns the last child of the node.
33 children
35 This method returns the children of the Node. If called in scalar
36 context it returns the number of children.
37 contains
39 print $node->contains( $elem ) ? "yes\n" : "no\n";
40 This method returns true if the given element is contained in the node,
42 or false otherwise.
43 elements
45 This method returns the elements in the Node. For a
46 "PPIx::Regexp::Node" proper, it is the same as "children()".
47 find
49 my $rslt = $node->find( 'PPIx::Regexp::Token::Literal' );
50 my $rslt = $node->find( 'Token::Literal' );
51 my $rslt = $node->find( sub {
52 return $_[1]->isa( 'PPIx::Regexp::Token::Literal' )
53 && $_[1]->ordinal < ord(' ');
54 } );
55 This method finds things.
57 If given a string as argument, it is assumed to be a class name
59 (possibly without the leading 'PPIx::Regexp::'), and all elements of
60 the given class are found.
61 If given a code reference, that code reference is called once for each
63 element, and passed $self and the element. The code should return true
64 to accept the element, false to reject it, and ( for subclasses of
65 "PPIx::Regexp::Node") "undef" to prevent recursion into the node. If
66 the code throws an exception, you get nothing back from this method.
67 Either way, the return is a reference to the list of things found, a
69 false (but defined) value if nothing was found, or "undef" if an error
70 occurred.
71 find_parents
73 my $rslt = $node->find_parents( sub {
74 return $_[1]->isa( 'PPIx::Regexp::Token::Operator' )
75 && $_[1]->content() eq '|';
76 } );
77 This convenience method takes the same arguments as "find", but instead
79 of the found objects themselves returns their parents. No parent will
80 appear more than once in the output.
81 This method returns a reference to the array of parents if any were
83 found. If no parents were found the return is false but defined. If an
84 error occurred the return is "undef".
85 find_first
87 This method has the same arguments as "find", but returns either a
88 reference to the first element found, a false (but defined) value if no
89 elements were found, or "undef" if an error occurred.
90 first_element
92 This method returns the first element in the node.
93 first_token
95 This method returns the first token in the node. If there is none, it
96 returns nothing.
97 last_element
99 This method returns the last element in the node.
100 last_token
102 This method returns the last token in the node. If there is none, it
103 returns nothing.
104 is_matcher
106 This method returns a true value if any of the node's children does.
107 Otherwise it returns "undef" if any of the node's children does.
108 Otherwise it returns a false (but defined) value.
109 perl_version_introduced
111 This method returns the maximum value of "perl_version_introduced"
112 returned by any of its elements. In other words, it returns the minimum
113 version of Perl under which this node is valid. If there are no
114 elements, 5.000 is returned, since that is the minimum value of Perl
115 supported by this package.
116 perl_version_removed
118 This method returns the minimum defined value of "perl_version_removed"
119 returned by any of the node's elements. In other words, it returns the
120 lowest version of Perl in which this node is "not" valid. If there are
121 no elements, or if no element has a defined "perl_version_removed",
122 "undef" is returned.
123 schild
125 This method returns the significant child at the given index; that is,
126 "$node->schild(0)" returns the first significant child,
127 "$node->schild(1)" returns the second significant child, and so on.
128 Negative indices count from the end.
129 schildren
131 This method returns the significant children of the Node. If called in
132 scalar context it returns the number of significant children.
133
135 Support is by the author. Please file bug reports at
136 <https://rt.cpan.org/Public/Dist/Display.html?Name=PPIx-Regexp>,
137 <https://github.com/trwyant/perl-PPIx-Regexp/issues>, or in electronic
138 mail to the author.
139
141 Thomas R. Wyant, III wyant at cpan dot org
142
144 Copyright (C) 2009-2021 by Thomas R. Wyant, III
145 This program is free software; you can redistribute it and/or modify it
147 under the same terms as Perl 5.10.0. For more details, see the full
148 text of the licenses in the directory LICENSES.
149 This program is distributed in the hope that it will be useful, but
151 without any warranty; without even the implied warranty of
152 merchantability or fitness for a particular purpose.
153perl v5.34.0 2021-10-25 PPIx::Regexp::Node(3)