1PPIx::Regexp::Node(3) User Contributed Perl DocumentationPPIx::Regexp::Node(3)
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6 PPIx::Regexp::Node - Represent a container
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9 use PPIx::Regexp::Dumper;
10 PPIx::Regexp::Dumper->new( 'qr{(foo)}' )->print();
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13 "PPIx::Regexp::Node" is a PPIx::Regexp::Element.
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15 "PPIx::Regexp::Node" is the parent of PPIx::Regexp,
16 PPIx::Regexp::Node::Range and PPIx::Regexp::Structure.
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19 This class represents a structural element that contains other classes.
20 It is an abstract class, not instantiated by the lexer.
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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.
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27 child
28 my $kid = $node->child( 0 );
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30 This method returns the child at the given index. The indices start
31 from zero, and negative indices are from the end of the list, so that
32 "$node->child( -1 )" returns the last child of the node.
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34 children
35 This method returns the children of the Node. If called in scalar
36 context it returns the number of children.
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38 contains
39 print $node->contains( $elem ) ? "yes\n" : "no\n";
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41 This method returns true if the given element is contained in the node,
42 or false otherwise.
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44 elements
45 This method returns the elements in the Node. For a
46 "PPIx::Regexp::Node" proper, it is the same as "children()".
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48 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 } );
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56 This method finds things.
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58 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.
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62 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.
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68 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.
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72 find_parents
73 my $rslt = $node->find_parents( sub {
74 return $_[1]->isa( 'PPIx::Regexp::Token::Operator' )
75 && $_[1]->content() eq '|';
76 } );
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78 This convenience method takes the same arguments as "find", but instead
79 of the found objects themselves returns their parents. No parent will
80 appear more than once in the output.
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82 This method returns a reference to the array of parents if any were
83 found. If no parents were found the return is false but defined. If an
84 error occurred the return is "undef".
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86 find_first
87 This method has the same arguments as "find", but returns either a
88 reference to the first element found, a false (but defined) value if no
89 elements were found, or "undef" if an error occurred.
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91 first_element
92 This method returns the first element in the node.
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94 last_element
95 This method returns the last element in the node.
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97 perl_version_introduced
98 This method returns the maximum value of "perl_version_introduced"
99 returned by any of its elements. In other words, it returns the minimum
100 version of Perl under which this node is valid. If there are no
101 elements, 5.000 is returned, since that is the minimum value of Perl
102 supported by this package.
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104 perl_version_removed
105 This method returns the minimum defined value of "perl_version_removed"
106 returned by any of the node's elements. In other words, it returns the
107 lowest version of Perl in which this node is "not" valid. If there are
108 no elements, or if no element has a defined "perl_version_removed",
109 "undef" is returned.
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111 schild
112 This method returns the significant child at the given index; that is,
113 "$node->schild(0)" returns the first significant child,
114 "$node->schild(1)" returns the second significant child, and so on.
115 Negative indices count from the end.
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117 schildren
118 This method returns the significant children of the node.
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121 Support is by the author. Please file bug reports at
122 <https://rt.cpan.org>, or in electronic mail to the author.
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125 Thomas R. Wyant, III wyant at cpan dot org
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128 Copyright (C) 2009-2020 by Thomas R. Wyant, III
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130 This program is free software; you can redistribute it and/or modify it
131 under the same terms as Perl 5.10.0. For more details, see the full
132 text of the licenses in the directory LICENSES.
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134 This program is distributed in the hope that it will be useful, but
135 without any warranty; without even the implied warranty of
136 merchantability or fitness for a particular purpose.
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140perl v5.30.1 2020-02-10 PPIx::Regexp::Node(3)