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Diffstat (limited to 'lib/FLAT/Regex.pm')
| -rw-r--r-- | lib/FLAT/Regex.pm | 194 |
1 files changed, 0 insertions, 194 deletions
diff --git a/lib/FLAT/Regex.pm b/lib/FLAT/Regex.pm deleted file mode 100644 index 2c5c243..0000000 --- a/lib/FLAT/Regex.pm +++ /dev/null @@ -1,194 +0,0 @@ -package FLAT::Regex; -use base 'FLAT'; -use strict; -use Carp; - -use FLAT::Regex::Parser; -use FLAT::Regex::Op; - -my $PARSER = FLAT::Regex::Parser->new(qw[ alt concat star ]); -#### TODO: error checking in the parse - -sub _parser { $PARSER } - -sub new { - my ($pkg, $string) = @_; - my $result = $pkg->_parser->parse($string) - or croak qq[``$string'' is not a valid regular expression]; - - $pkg->_from_op( $result ); -} - -sub _from_op { - my ($proto, $op) = @_; - $proto = ref $proto || $proto; ## I really do want this - - bless [ $op ], $proto; -} - -sub op { - $_[0][0]; -} - -use overload '""' => 'as_string'; -sub as_string { - $_[0]->op->as_string(0); -} - -sub as_perl_regex { - my ($self, %opts) = @_; - - my $fmt = $opts{anchored} ? '(?:\A%s\z)' : '(?:%s)'; - return sprintf $fmt, $self->op->as_perl_regex(0); -} - -sub contains { - my ($self, $string) = @_; - $string =~ $self->as_perl_regex(anchored => 1); -} - -sub as_nfa { - $_[0]->op->as_nfa; -} - -sub as_pfa { - $_[0]->op->as_pfa; -} - -#### regular language standard interface implementation: -#### TODO: parameter checking? - -sub as_regex { - $_[0]; -} - -sub union { - my $self = $_[0]; - my $op = FLAT::Regex::op::alt->new( map { $_->as_regex->op } @_ ); - $self->_from_op($op); -} - -sub intersect { - my @dfas = map { $_->as_dfa } @_; - my $self = shift @dfas; - $self->intersect(@dfas)->as_regex; -} - -sub complement { - my $self = shift; - $self->as_dfa->complement->as_regex; -} - -sub concat { - my $self = $_[0]; - my $op = FLAT::Regex::op::concat->new( map { $_->as_regex->op } @_ ); - $self->_from_op($op); -} - -sub kleene { - my $self = shift; - my $op = FLAT::Regex::op::star->new( $self->op ); - $self->_from_op($op); -} - -sub reverse { - my $self = shift; - my $op = $self->op->reverse; - $self->_from_op($op); -} - -sub is_empty { - $_[0]->op->is_empty; -} - -sub is_finite { - $_[0]->op->is_finite; -} - -1; - -__END__ - -=head1 NAME - -FLAT::Regex - Regular expressions - -=head1 SYNOPSIS - -A FLAT::Regex object is a regular expression. - -=head1 USAGE - -In addition to implementing the interface specified in L<FLAT>, FLAT::Regex -objects provide the following regex-specific methods: - -=over - -=item FLAT::Regex-E<gt>new($string) - -Returns a regex object representing the expression given in $string. C<|> -and C<+> can both be used to denote alternation. C<*> denotes Kleene star, and -parentheses can be used for grouping. No other features or shortcut notation -is currently supported (character classes, {n,m} repetition, etc). - -Whitespaces is ignored. To specify a literal space, use C<[ ]>. This syntax -can also be used to specify atomic "characters" longer than a single -character. For example, the expression: - - [foo]abc[bar]* - -is treated as a regular expression over the symbols "a", "b", "c", "foo", -and "bar". In particular, this means that when the regular expression is -reversed, "foo" and "bar" remain the same (i.e, they do not become "oof" and -"rab"). - -The empty regular expression (epsilon) is written as C<[]>, and the null -regular expression (sometimes called phi) is specified with the C<#> -character. To specify a literal hash-character, use C<[#]>. Including -literal square bracket characters is currently not supported. - -The expression "" (or any string containing only whitespace) is not a valid -FLAT regex expression. Either C<[]> or C<#> are probably what was intended. - -=item $regex-E<gt>as_string - -Returns the string representation of the regex, in the same format as above. -It is NOT necessarily true that - - FLAT::Regex->new($string)->as_string - -is identical to $string, especially if $string contains whitespace or -redundant parentheses. - -=item $regex-E<gt>as_perl_regex - -=item $regex-E<gt>as_perl_regex(anchored => $bool); - -Returns an equivalent Perl regular expression. If the "anchored" option -is set to a true value, the regular expression will be anchored with -C<\A> and C<\z>. The default behavior is to omit the anchors. - -The Perl regex will not contain capturing parentheses. "Extended" characters -that are written as "[char]" in FLAT regexes will be written without the -square brackets in the corresponding Perl regex. So the following: - - FLAT::Regex->new("[foo][bar]*")->as_perl_regex - -will be equal to "(?:foo(?:bar)*)". - -=back - -=head1 AUTHORS & ACKNOWLEDGEMENTS - -FLAT is written by Mike Rosulek E<lt>mike at mikero dot comE<gt> and -Brett Estrade E<lt>estradb at gmail dot comE<gt>. - -The initial version (FLAT::Legacy) by Brett Estrade was work towards an -MS thesis at the University of Southern Mississippi. - -Please visit the Wiki at http://www.0x743.com/flat - -=head1 LICENSE - -This module is free software; you can redistribute it and/or modify it under -the same terms as Perl itself. |