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PPIx::Regexp::Token::MUseriContributed Perl DoPPIx::Regexp::Token::Modifier(3)

NAME
       PPIx::Regexp::Token::Modifier - Represent modifiers.

SYNOPSIS
	use PPIx::Regexp::Dumper;
	PPIx::Regexp::Dumper->new( 'qr{foo}smx'	)
	    ->print();

       The trailing "smx" will be represented by this class.

       This class also represents the whole of things like "(?ismx)". But the
       modifiers in something like "(?i:foo)" are represented by a
       PPIx::Regexp::Token::GroupType::Modifier.

INHERITANCE
       "PPIx::Regexp::Token::Modifier" is a PPIx::Regexp::Token.

       "PPIx::Regexp::Token::Modifier" is the parent of
       PPIx::Regexp::Token::GroupType::Modifier.

DESCRIPTION
       This class represents modifier characters at the	end of the regular
       expression.  For	example, in "qr{foo}smx" this class would represent
       the terminal "smx".

   The "a", "aa", "d", "l", and	"u" modifiers
       The "a",	"aa", "d", "l",	and "u"	modifiers, introduced starting in Perl
       5.13.6, are used	to force either	Unicode	pattern	semantics ("u"),
       locale semantics	("l") default semantics	("d" the traditional Perl
       semantics, which	can also mean 'dual' since it means Unicode if the
       string's	UTF-8 bit is on, and locale if the UTF-8 bit is	off), or
       restricted default semantics ("a"). These are mutually exclusive, and
       only one	can be asserted	at a time. Asserting any of these overrides
       the inherited value of any of the others. The "asserted()" method
       reports as asserted the last one	it sees, or none of them if it has
       seen none.

       For example, given "PPIx::Regexp::Token::Modifier" $elem	representing
       the invalid regular expression fragment "(?dul)", "$elem->asserted( 'l'
       )" would	return true, but "$elem->asserted( 'u' )" would	return false.
       Note that "$elem->negated( 'u' )" would also return false, since	"u" is
       not explicitly negated.

       If $elem	represented regular expression fragment	"(?i)",
       "$elem->asserted( 'd' )"	would return false, since even though "d"
       represents the default behavior it is not explicitly asserted.

   The caret ("^") modifier
       Calling "^" a modifier is a bit of a misnomer. The "(?^...)"
       construction was	introduced in Perl 5.13.6, to prevent the inheritance
       of modifiers. The documentation calls the caret a shorthand equivalent
       for "d-imsx", and that it the way this class handles it.

       For example, given "PPIx::Regexp::Token::Modifier" $elem	representing
       regular expression fragment "(?^i)", "$elem->asserted( 'd' )" would
       return true, since in the absence of an explicit	"l" or "u" this	class
       considers the "^" to explicitly assert "d".

       Note that if this is retracted before Perl 5.14 is released, this
       support will disappear. See "NOTICE" in PPIx::Regexp for	some
       explanation.

METHODS
       This class provides the following public	methods. Methods not
       documented here are private, and	unsupported in the sense that the
       author reserves the right to change or remove them without notice.

   asserts
	$token->asserts( 'i' ) and print "token	asserts	i";
	foreach	( $token->asserts() ) {	print "token asserts $_\n" }

       This method returns true	if the token explicitly	asserts	the given
       modifier. The example would return true for the modifier	in "(?i:foo)",
       but false for "(?-i:foo)".

       Starting	with version 0.036_01, if the argument is a single-character
       modifier	followed by an asterisk	(intended as a wild card character),
       the return is the number	of times that modifier appears.	In this	case
       an exception will be thrown if you specify a multi-character modifier
       (e.g.  'ee*'), or if you	specify	one of the match semantics modifiers
       (e.g.  'a*').

       If called without an argument, or with an undef argument, all modifiers
       explicitly asserted by this token are returned.

   match_semantics
	my $sem	= $token->match_semantics();
	defined	$sem or	$sem = 'undefined';
	print "This token has $sem match semantics\n";

       This method returns the match semantics asserted	by the token, as one
       of the strings 'a', 'aa', 'd', 'l', or 'u'. If no explicit match
       semantics are asserted, this method returns "undef".

   modifiers
	my %mods = $token->modifiers();

       Returns all modifiers asserted or negated by this token,	and the	values
       set (true for asserted, false for negated). If called in	scalar
       context,	returns	a reference to a hash containing the values.

   negates
	$token->negates( 'i' ) and print "token	negates	i\n";
	foreach	( $token->negates() ) {	print "token negates $_\n" }

       This method returns true	if the token explicitly	negates	the given
       modifier. The example would return true for the modifier	in
       "(?-i:foo)", but	false for "(?i:foo)".

       If called without an argument, or with an undef argument, all modifiers
       explicitly negated by this token	are returned.

SUPPORT
       Support is by the author. Please	file bug reports at
       <http://rt.cpan.org>, or	in electronic mail to the author.

AUTHOR
       Thomas R. Wyant,	III wyant at cpan dot org

COPYRIGHT AND LICENSE
       Copyright (C) 2009-2014 by Thomas R. Wyant, III

       This program is free software; you can redistribute it and/or modify it
       under the same terms as Perl 5.10.0. For	more details, see the full
       text of the licenses in the directory LICENSES.

       This program is distributed in the hope that it will be useful, but
       without any warranty; without even the implied warranty of
       merchantability or fitness for a	particular purpose.

perl v5.24.1			  2014-11-12  PPIx::Regexp::Token::Modifier(3)

NAME | SYNOPSIS | INHERITANCE | DESCRIPTION | METHODS | SUPPORT | AUTHOR | COPYRIGHT AND LICENSE

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