Regexp/Parser/JavaScript.pod

=head1 NAME

Regexp::Parser::JavaScript - A Regexp::Parser Subclass for JavaScript
Regular Expressions

=head1 SYNOPSIS

  use Regexp::Parser::JavaScript;
  
  my $parser = Regexp::Parser::JavaScript->new;
  
  my @error;
  
  ## Prepare a callback function invoked whenever an error or warning
  ## is raised by the parser.
  $parser->onerror (sub {
    my %args = @_;
    
    my $error_message = '';
    if ($args{level} eq 'w') {
      $error_message .= 'Warning: ';
    } else {
      $error_message .= 'Error: ';
    }
    
    $error_message .= sprintf $args{type}, @{$args{args}};
    
    $error_message .= ' (';
    $error_message .= substr ${$args{valueref}},
        $args{pos_start}, $args{pos_end} - $args{pos_start};
    $error_message .= ')';
    
    $error_message .= "\n";
    
    push @error, $error_message;
  });
  
  ## Parse the regular expression given as a string.
  ## Use |eval| to catch an exception that would be thrown if the
  ## regular expression contains a fatal error.
  eval {
    $parser->parse ($regexp_as_string);
  };
  
  if ($parser->errnum) {
    ## @error contains at least one fatal error.
    warn @error;
  } else {
    ## @error contains no fatal error.
    warn @error;
    
    ## Now, $parser->root contains the root node of the parsed regular
    ## expression tree.  See |perldoc Regexp::Parser| for more information.
  }

=head1 DESCRIPTION

The C<Regexp::Parser::JavaScript> modules provides a subclass of the
C<Regexp::Parser>, a regular expression parser module.  The
C<Regexp::Parser::JavaScript> module provides an implementation of the
parser for the regular expression language as defined by ECMA 376
Third Edition (the ECMAScript specification), modified for
compatibility with Web browser implementations.

Apart from this additional function, this module provides the same
interface as the one applied by the C<Regexp::Parser::Perl58> module.
For more information, see L<Regexp::Parser::Perl58>.

=head1 METHODS

The C<Regexp::Parser::JavaScript> module provides same methods as
C<Regexp::Parser::JavaScript>.  See L<Regexp::Parser::Perl58>.

=head1 ERROR TYPES

The C<Regexp::Parser::JavaScript> module reports same kinds of errors
as the C<Regexp::Parser> module does to the callback function
specified by the C<onerror> method, if any.  In addition, it might
also have an additional error type: C<RPJSe_OCTESC>.

=over 4

=item RPJSe_OCTESC

This error is reported when an octal escape sequence is used in the
regular expression.  The octal escape sequence is I<not> part of the
ECMAScript specification though it is supported by Web browsers for
backward compatibility.

=back

=head1 DEPENDENCY

This module requires Perl 5.10.0 or later.

This module depends on C<Regexp::Parser> and C<Regexp::Parser::Perl58>
modules.

=head1 SEE ALSO

The latest version of this module is available at
L<http://suika.fam.cx/regexp/>.

Regular expression visualizer
L<http://suika.fam.cx/regexp/visualizer/input>.  It uses this module
to parse Perl 5.8 regular expressions.

L<Regexp::Parser> - A superclass, available from CPAN.

L<Regexp::Parser::Perl58> - A superclass.

=head1 DEVELOPMENT

CVS log:
L<http://suika.fam.cx/regexp/lib/Regexp/Parser/JavaScript.pm,cvslog>.

Bug tracking system: L<http://manakai.g.hatena.ne.jp/task/7/>.

=head1 AUTHOR

Wakaba <w@suika.fam.cx>.

=head1 LICENSE

Copyright 2008-2009 Wakaba <w@suika.fam.cx>.

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.

=cut

# $Date: 2009/01/13 14:15:47 $
1	=head1 NAME
2
3	Regexp::Parser::JavaScript - A Regexp::Parser Subclass for JavaScript
4	Regular Expressions
5
6	=head1 SYNOPSIS
7
8	use Regexp::Parser::JavaScript;
9
10	my $parser = Regexp::Parser::JavaScript->new;
11
12	my @error;
13
14	## Prepare a callback function invoked whenever an error or warning
15	## is raised by the parser.
16	$parser->onerror (sub {
17	my %args = @_;
18
19	my $error_message = '';
20	if ($args{level} eq 'w') {
21	$error_message .= 'Warning: ';
22	} else {
23	$error_message .= 'Error: ';
24	}
25
26	$error_message .= sprintf $args{type}, @{$args{args}};
27
28	$error_message .= ' (';
29	$error_message .= substr ${$args{valueref}},
30	$args{pos_start}, $args{pos_end} - $args{pos_start};
31	$error_message .= ')';
32
33	$error_message .= "\n";
34
35	push @error, $error_message;
36	});
37
38	## Parse the regular expression given as a string.
39	## Use \|eval\| to catch an exception that would be thrown if the
40	## regular expression contains a fatal error.
41	eval {
42	$parser->parse ($regexp_as_string);
43	};
44
45	if ($parser->errnum) {
46	## @error contains at least one fatal error.
47	warn @error;
48	} else {
49	## @error contains no fatal error.
50	warn @error;
51
52	## Now, $parser->root contains the root node of the parsed regular
53	## expression tree. See \|perldoc Regexp::Parser\| for more information.
54	}
55
56	=head1 DESCRIPTION
57
58	The C<Regexp::Parser::JavaScript> modules provides a subclass of the
59	C<Regexp::Parser>, a regular expression parser module. The
60	C<Regexp::Parser::JavaScript> module provides an implementation of the
61	parser for the regular expression language as defined by ECMA 376
62	Third Edition (the ECMAScript specification), modified for
63	compatibility with Web browser implementations.
64
65	Apart from this additional function, this module provides the same
66	interface as the one applied by the C<Regexp::Parser::Perl58> module.
67	For more information, see L<Regexp::Parser::Perl58>.
68
69	=head1 METHODS
70
71	The C<Regexp::Parser::JavaScript> module provides same methods as
72	C<Regexp::Parser::JavaScript>. See L<Regexp::Parser::Perl58>.
73
74	=head1 ERROR TYPES
75
76	The C<Regexp::Parser::JavaScript> module reports same kinds of errors
77	as the C<Regexp::Parser> module does to the callback function
78	specified by the C<onerror> method, if any. In addition, it might
79	also have an additional error type: C<RPJSe_OCTESC>.
80
81	=over 4
82
83	=item RPJSe_OCTESC
84
85	This error is reported when an octal escape sequence is used in the
86	regular expression. The octal escape sequence is I<not> part of the
87	ECMAScript specification though it is supported by Web browsers for
88	backward compatibility.
89
90	=back
91
92	=head1 DEPENDENCY
93
94	This module requires Perl 5.10.0 or later.
95
96	This module depends on C<Regexp::Parser> and C<Regexp::Parser::Perl58>
97	modules.
98
99	=head1 SEE ALSO
100
101	The latest version of this module is available at
102	L<http://suika.fam.cx/regexp/>.
103
104	Regular expression visualizer
105	L<http://suika.fam.cx/regexp/visualizer/input>. It uses this module
106	to parse Perl 5.8 regular expressions.
107
108	L<Regexp::Parser> - A superclass, available from CPAN.
109
110	L<Regexp::Parser::Perl58> - A superclass.
111
112	=head1 DEVELOPMENT
113
114	CVS log:
115	L<http://suika.fam.cx/regexp/lib/Regexp/Parser/JavaScript.pm,cvslog>.
116
117	Bug tracking system: L<http://manakai.g.hatena.ne.jp/task/7/>.
118
119	=head1 AUTHOR
120
121	Wakaba <w@suika.fam.cx>.
122
123	=head1 LICENSE
124
125	Copyright 2008-2009 Wakaba <w@suika.fam.cx>.
126
127	This library is free software; you can redistribute it and/or modify
128	it under the same terms as Perl itself.
129
130	=cut
131
132	# $Date: 2009/01/13 14:15:47 $