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Pugs::Compiler::Regex.3pm
Langue: en
Version: 2008-07-29 (fedora - 05/07/09)
Section: 3 (Bibliothèques de fonctions)
NAME
Pugs::Compiler::Regex - Compiler for Perl 6 RegexSYNOPSIS
use Pugs::Compiler::Regex; use Pugs::Runtime::Match; $regex = Pugs::Compiler::Regex->compile('a*b'); $match = $regex->match('aaab'); print $match->(), "\n"; print $match->from, "\n"; print $match->to, "\n"; package MyGrammar; $regex = Pugs::Compiler::Regex->compile( 'a*', { ratchet => 1, continue => 1, sigspace => 1 } ); *my_match = $regex->code(); $match = MyGrammar->my_match('aaaa'); print "$match\n"; package MyGrammar2; $regex = Pugs::Compiler::Regex->install( my_match => 'a*', { ratchet => 1, continue => 1, sigspace => 1 } ); $match = MyGrammar->my_match('aaaa'); print "$match\n";
DESCRIPTION
This class provides an implementation for Perl 6 regexes. It serves as a base class for Pugs::Compiler::Rule and Pugs::Compiler::Token.METHODS
- "$regex = Pugs::Compiler::Regex->compile($str, $params);"
- This method acts like a constructor, which returns a Pugs::Compiler::Regex object from the p6 regex specified in $str, or throws an exception on invalid rule syntax.
$params is an optional argument which specifies the following p6 regex modifiers:
-
- "grammar => 'Pugs::Grammar::Base'"
- Specify which namespace (Grammar) the rule belongs to. if "grammar" is not specified, then "Pugs::Grammar::Base" will be assumed.
- "continue => 0"
- "c => 0"
- These modifiers cause the pattern to continue scanning from the string's current "pos":
Note that in Perl 6 form
m:c/pattern/
is roughlh equivalent to
m:p/ .*? pattern /
Here is an example:
package Foo; Pugs::Compiler::Regex->install( word => '\w+', { ratchet => 1, continue => 1 } ); $s = 'hello world'; $match = Foo->word($s); # got 'hello' $match = Foo->word($s); # got 'world'
XXX Note that "continue" or "c" currently are not supported in non-ratchet mode.
- "ratchet => 0"
- Disable backtracking. Much faster. Defaults to 0. (Pugs::Compiler::Rule and Pugs::Compiler::Token have the default value of 1).
- "pos => undef"
- "p => undef"
- Specify a string position to match. Starts from zero. Defaults to "undef", which matches anywhere in the string.
- "sigspace => 0"
- Whitespace is significant. Defaults to 0 for Pugs::Compiler::Regex while 1 for Pugs::Compiler::Rule.
- "ignorecase => 0"
- Ignore character case. Defaults to 0 for Pugs::Compiler::Regex.
-
- "$regex->perl5()"
- "$regex->perl()"
- Return a string holding the Perl 5 code for reconstructing the current Pugs::Compiler::Regex object.
We are trying to make the "perl5" method does something like serializing a Pugs::Compiler::Regex instance.
If you want the raw Perl 5 code generated by the various emitters, use "$regex->{perl5}" directly.
- "$regex->match($str, $grammar, $params)"
- Performs matching action on $str. Note that it's a thin wrapper around the p5 code compiled from the p6 regex with run-time modifier handling via the $params argument.
Here is an example:
$regex = Pugs::Compiler::regex->compile('a*\w'); my $match = $regex->match('aaa'); print "Capture: $match"; print "From: ", $match->from; print "To: ", $match->to;
- "$regex->code()"
- Returns a closure (or an anonymous sub) which does the actual matching task. For example:
$regex = Pugs::Compiler::Regex->compile('a|b', { ratchet => 1 }); my $sub = $regex->code(); my $match = $sub->('MyGrammar', 'aaa');
Or inserts the sub into the current package:
package Foo; $regex = Pugs::Compiler::Regex->compile('a*'); *match = $regex->code(); my $match = __PACKAGE__->match('aaa');
Technically it's a thin wrapper around the "match" method.
- "$regex->install($name, @args_for_compile)"
- Installs the subroutine returned from the "code" method as a named subroutine using the name specified by $name;
If $name is fully qualified, then the corresponding package is used, otherwise the current package is assumed.
@args_for_compile are those arguments fed into the "compile" method.
It will croak if there's already a sub with the same name exists. If that's not what you want, use the "reinstall" method instead.
Here are some examples:
package Bar; Pugs::Compiler::Regex->install(match => 'a*', {ratchet => 1}); $match = Bar->match('aaa'); # The following line dies with the message # "Can't install regex 'match' as 'Bar::match' which already # exists": Pugs::Compiler::Regex->install(match => 'b*');
- "$regex->reinstall($name, @args_for_compile)"
- Like the "install" method but it can replaces the named sub if it already exists:
package Bar; Pugs::Compiler::Regex->install('match', 'a*', {ratchet => 1}); Pugs::Compiler::Regex->reinstall('match', 'b*'); }; $match = Bar->match('bbb'); # matched here
PACKAGE VARIABLES
- $Pugs::Compiler::Regex::NoCache
- By default, the "compile" method will cache the compiled form (p5 source) of the p6 regex. The "NoCache" variable prevents any caching.
AUTHORS
The Pugs Team <perl6-compiler@perl.org>.SEE ALSO
The Perl 6 Rules Spec: <http://dev.perl.org/perl6/doc/design/syn/S05.html>COPYRIGHT
Copyright 2006 by Flavio Soibelmann Glock and others.This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
See <http://www.perl.com/perl/misc/Artistic.html>
Contenus ©2006-2024 Benjamin Poulain
Design ©2006-2024 Maxime Vantorre