—————=head1 NAME
PPIx::Regexp::Structure - Represent a structure.
=head1 SYNOPSIS
use PPIx::Regexp::Dumper;
PPIx::Regexp::Dumper->new( 'qr{(foo)}' )->print();
=head1 INHERITANCE
C<PPIx::Regexp::Structure> is a
L<PPIx::Regexp::Node|PPIx::Regexp::Node>.
C<PPIx::Regexp::Structure> is the parent of
L<PPIx::Regexp::Structure::Assertion|PPIx::Regexp::Structure::Assertion>,
L<PPIx::Regexp::Structure::BranchReset|PPIx::Regexp::Structure::BranchReset>,
L<PPIx::Regexp::Structure::Capture|PPIx::Regexp::Structure::Capture>,
L<PPIx::Regexp::Structure::CharClass|PPIx::Regexp::Structure::CharClass>,
L<PPIx::Regexp::Structure::Code|PPIx::Regexp::Structure::Code>,
L<PPIx::Regexp::Structure::Main|PPIx::Regexp::Structure::Main>,
L<PPIx::Regexp::Structure::Modifier|PPIx::Regexp::Structure::Modifier>,
L<PPIx::Regexp::Structure::Quantifier|PPIx::Regexp::Structure::Quantifier>,
L<PPIx::Regexp::Structure::Subexpression|PPIx::Regexp::Structure::Subexpression>,
L<PPIx::Regexp::Structure::Switch|PPIx::Regexp::Structure::Switch> and
L<PPIx::Regexp::Structure::Unknown|PPIx::Regexp::Structure::Unknown>.
=head1 DESCRIPTION
This class represents a bracketed construction of some sort. The
brackets considered part of the structure, but not inside it. So the
C<elements()> method returns the brackets if they are defined, but the
C<children()> method does not.
=head1 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.
=cut
package
PPIx::Regexp::Structure;
use
strict;
use
warnings;
our
$VERSION
=
'0.039_02'
;
sub
_new {
my
(
$class
,
@args
) =
@_
;
my
%brkt
;
if
(
ref
$args
[0] eq
'HASH'
) {
%brkt
= %{
shift
@args
};
foreach
my
$key
(
qw{ start type finish }
) {
ref
$brkt
{
$key
} eq
'ARRAY'
or
$brkt
{
$key
} = [
$brkt
{
$key
} ];
}
}
else
{
$brkt
{finish} = [
@args
?
pop
@args
: () ];
$brkt
{start} = [
@args
?
shift
@args
: () ];
while
(
@args
&& !
$args
[0]->significant() ) {
push
@{
$brkt
{start} },
shift
@args
;
}
$brkt
{type} = [];
if
( __instance(
$args
[0],
'PPIx::Regexp::Token::GroupType'
) ) {
push
@{
$brkt
{type} },
shift
@args
;
while
(
@args
&& !
$args
[0]->significant() ) {
push
@{
$brkt
{type} },
shift
@args
;
}
}
}
$class
->_check_for_interpolated_match( \
%brkt
, \
@args
);
my
$self
=
$class
->SUPER::_new(
@args
)
or
return
;
if
( __instance(
$brkt
{type}[0],
'PPIx::Regexp::Token::GroupType'
) ) {
(
my
$reclass
=
ref
$brkt
{type}[0] ) =~
s/ Token::GroupType /Structure/smx;
$reclass
->can(
'start'
)
or confess
"Programming error - $reclass not loaded"
;
bless
$self
,
$reclass
;
}
foreach
my
$key
(
qw{ start type finish }
) {
$self
->{
$key
} = [];
ref
$brkt
{
$key
} eq
'ARRAY'
or confess
"Programming error - '$brkt{$key}' not an ARRAY"
;
foreach
my
$val
( @{
$brkt
{
$key
} } ) {
defined
$val
or
next
;
__instance(
$val
,
'PPIx::Regexp::Element'
)
or confess
"Programming error - '$val' not a "
,
"PPIx::Regexp::Element"
;
push
@{
$self
->{
$key
} },
$val
;
$val
->_parent(
$self
);
}
}
return
$self
;
}
sub
elements {
my
(
$self
) =
@_
;
if
(
wantarray
) {
return
(
@{
$self
->{start} },
@{
$self
->{type} },
@{
$self
->{children} },
@{
$self
->{finish} },
);
}
elsif
(
defined
wantarray
) {
my
$size
=
scalar
@{
$self
->{start} };
$size
+=
scalar
@{
$self
->{type} };
$size
+=
scalar
@{
$self
->{children} };
$size
+=
scalar
@{
$self
->{finish} };
return
$size
;
}
else
{
return
;
}
}
=head2 finish
my $elem = $struct->finish();
my @elem = $struct->finish();
my $elem = $struct->finish( 0 );
Returns the finishing structure element. This is included in the
C<elements> but not in the C<children>.
The finishing element is actually an array, though it should never have
more than one element. Calling C<finish> in list context gets you all
elements of the array. Calling it in scalar context gets you an element
of the array, defaulting to element 0 if no argument is passed.
=cut
sub
finish {
my
(
$self
,
$inx
) =
@_
;
wantarray
and
return
@{
$self
->{finish} };
return
$self
->{finish}[
defined
$inx
?
$inx
: 0 ];
}
sub
first_element {
my
(
$self
) =
@_
;
$self
->{start}[0] and
return
$self
->{start}[0];
$self
->{type}[0] and
return
$self
->{type}[0];
if
(
my
$elem
=
$self
->SUPER::first_element() ) {
return
$elem
;
}
$self
->{finish}[0] and
return
$self
->{finish}[0];
return
;
}
sub
last_element {
my
(
$self
) =
@_
;
$self
->{finish}[-1] and
return
$self
->{finish}[-1];
if
(
my
$elem
=
$self
->SUPER::last_element() ) {
return
$elem
;
}
$self
->{type}[-1] and
return
$self
->{type}[-1];
$self
->{start}[-1] and
return
$self
->{start}[-1];
return
;
}
=head2 start
my $elem = $struct->start();
my @elem = $struct->start();
my $elem = $struct->start( 0 );
Returns the starting structure element. This is included in the
C<elements> but not in the C<children>.
The starting element is actually an array. The first element (element 0)
is the actual starting delimiter. Subsequent elements, if any, are
insignificant elements (comments or white space) absorbed into the start
element for ease of parsing subsequent elements.
Calling C<start> in list context gets you all elements of the array.
Calling it in scalar context gets you an element of the array,
defaulting to element 0 if no argument is passed.
=cut
sub
start {
my
(
$self
,
$inx
) =
@_
;
wantarray
and
return
@{
$self
->{start} };
return
$self
->{start}[
defined
$inx
?
$inx
: 0 ];
}
=head2 type
my $elem = $struct->type();
my @elem = $struct->type();
my $elem = $struct->type( 0 );
Returns the group type if any. This will be the leading
L<PPIx::Regexp::Token::GroupType|PPIx::Regexp::Token::GroupType>
token if any. This is included in C<elements> but not in C<children>.
The type is actually an array. The first element (element 0) is the
actual type determiner. Subsequent elements, if any, are insignificant
elements (comments or white space) absorbed into the type element for
consistency with the way the start element is handled.
Calling C<type> in list context gets you all elements of the array.
Calling it in scalar context gets you an element of the array,
defaulting to element 0 if no argument is passed.
=cut
sub
type {
my
(
$self
,
$inx
) =
@_
;
wantarray
and
return
@{
$self
->{type} };
return
$self
->{type}[
defined
$inx
?
$inx
: 0 ];
}
# Check for things like (?$foo:...) or (?$foo)
sub
_check_for_interpolated_match {
my
(
$class
,
$brkt
,
$args
) =
@_
;
# Everything we are interested in begins with a literal '?' followed
# by an interpolation.
__instance(
$args
->[0],
'PPIx::Regexp::Token::Unknown'
)
and
$args
->[0]->content() eq
'?'
and __instance(
$args
->[1],
'PPIx::Regexp::Token::Interpolation'
)
or
return
;
my
$hiwater
= 2;
# Record how far we got into the arguments for
# subsequent use detecting things like
# (?$foo).
# If we have a literal ':' as the third argument:
# GroupType::Modifier, rebless the ':' so we know not to match
# against it, and splice all three tokens into the type.
if
( __instance(
$args
->[2],
'PPIx::Regexp::Token::Literal'
)
&&
$args
->[2]->content() eq
':'
) {
# Rebless the '?' as a GroupType::Modifier.
bless
$args
->[0],
'PPIx::Regexp::Token::GroupType::Modifier'
;
# Note that we do _not_ want __PPIX_TOKEN__post_make here.
# Rebless the ':' as a GroupType, just so it does not look like
# something to match against.
bless
$args
->[2],
'PPIx::Regexp::Token::GroupType'
;
# Shove our three significant tokens into the type.
push
@{
$brkt
->{type} },
splice
@{
$args
}, 0, 3;
# Stuff all the immediately-following insignificant tokens into
# the type as well.
while
( @{
$args
} && !
$args
->[0]->significant() ) {
push
@{
$brkt
->{type} },
shift
@{
$args
};
}
# Return to the caller, since we have done all the damage we
# can.
return
;
}
# If we have a literal '-' as the third argument, we might have
# something like (?$on-$off:$foo).
if
( __instance(
$args
->[2],
'PPIx::Regexp::Token::Literal'
)
&&
$args
->[2]->content() eq
'-'
&& __instance(
$args
->[3],
'PPIx::Regexp::Token::Interpolation'
)
) {
$hiwater
= 4;
if
( __instance(
$args
->[4],
'PPIx::Regexp::Token::Literal'
)
&&
$args
->[4]->content() eq
':'
) {
# Rebless the '?' as a GroupType::Modifier.
bless
$args
->[0],
'PPIx::Regexp::Token::GroupType::Modifier'
;
# Note that we do _not_ want __PPIX_TOKEN__post_make here.
# Rebless the '-' and ':' as GroupType, just so they do not
# look like something to match against.
bless
$args
->[2],
'PPIx::Regexp::Token::GroupType'
;
bless
$args
->[4],
'PPIx::Regexp::Token::GroupType'
;
# Shove our five significant tokens into the type.
push
@{
$brkt
->{type} },
splice
@{
$args
}, 0, 5;
# Stuff all the immediately-following insignificant tokens
# into the type as well.
while
( @{
$args
} && !
$args
->[0]->significant() ) {
push
@{
$brkt
->{type} },
shift
@{
$args
};
}
# Return to the caller, since we have done all the damage we
# can.
return
;
}
}
# If the group contains _any_ significant tokens at this point, we
# do _not_ have something like (?$foo).
foreach
my
$inx
(
$hiwater
..
$#$args
) {
$args
->[
$inx
]->significant() and
return
;
}
# Rebless the '?' as a GroupType::Modifier.
bless
$args
->[0],
'PPIx::Regexp::Token::GroupType::Modifier'
;
# Note that we do _not_ want __PPIX_TOKEN__post_make here.
# Shove all the contents of $args into type, using splice to leave
# @{ $args } empty after we do this.
push
@{
$brkt
->{type} },
splice
@{
$args
};
# We have done all the damage we can.
return
;
}
sub
__error {
my
(
$self
,
$msg
) =
@_
;
defined
$msg
or
$msg
=
'Was class '
.
ref
$self
;
$self
->{error} =
$msg
;
bless
$self
, STRUCTURE_UNKNOWN;
return
1;
}
1;
__END__
=head1 SUPPORT
Support is by the author. Please file bug reports at
L<http://rt.cpan.org>, or in electronic mail to the author.
=head1 AUTHOR
Thomas R. Wyant, III F<wyant at cpan dot org>
=head1 COPYRIGHT AND LICENSE
Copyright (C) 2009-2015 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.
=cut
# ex: set textwidth=72 :