1 package Package::Stash::PP;
4 # ABSTRACT: pure perl implementation of the Package::Stash API
8 use Scalar::Util qw(blessed reftype weaken);
10 # before 5.12, assigning to the ISA glob would make it lose its magical ->isa
12 use constant BROKEN_ISA_ASSIGNMENT => ($] < 5.012);
13 # before 5.10, stashes don't ever seem to drop to a refcount of zero, so
14 # weakening them isn't helpful
15 use constant BROKEN_WEAK_STASH => ($] < 5.010);
16 # before 5.10, the scalar slot was always treated as existing if the
18 use constant BROKEN_SCALAR_INITIALIZATION => ($] < 5.010);
26 This is a backend for L<Package::Stash> implemented in pure perl, for those without a compiler or who would like to use this inline in scripts.
34 if (!defined($package) || (ref($package) && ref($package) ne 'HASH')) {
35 confess "Package::Stash->new must be passed the name of the "
36 . "package to access";
38 elsif (ref($package) eq 'HASH') {
39 confess "The pure perl implementation of Package::Stash doesn't "
40 . "currently support anonymous stashes. You should install "
41 . "Package::Stash::XS";
43 elsif ($package !~ /\A[0-9A-Z_a-z]+(?:::[0-9A-Z_a-z]+)*\z/) {
44 confess "$package is not a module name";
48 'package' => $package,
53 confess "Can't call name as a class method"
54 unless blessed($_[0]);
55 return $_[0]->{package};
59 confess "Can't call namespace as a class method"
60 unless blessed($_[0]);
62 if (BROKEN_WEAK_STASH) {
64 return \%{$_[0]->name . '::'};
67 return $_[0]->{namespace} if defined $_[0]->{namespace};
71 $_[0]->{namespace} = \%{$_[0]->name . '::'};
74 weaken($_[0]->{namespace});
76 return $_[0]->{namespace};
89 sub _deconstruct_variable_name {
90 my ($self, $variable) = @_;
93 if (ref($variable) eq 'HASH') {
94 @ret = @{$variable}{qw[name sigil type]};
97 (defined $variable && length $variable)
98 || confess "You must pass a variable name";
100 my $sigil = substr($variable, 0, 1, '');
102 if (exists $SIGIL_MAP{$sigil}) {
103 @ret = ($variable, $sigil, $SIGIL_MAP{$sigil});
106 @ret = ("${sigil}${variable}", '', $SIGIL_MAP{''});
110 # XXX in pure perl, this will access things in inner packages,
111 # in xs, this will segfault - probably look more into this at
114 || confess "Variable names may not contain ::";
120 sub _valid_for_type {
122 my ($value, $type) = @_;
123 if ($type eq 'HASH' || $type eq 'ARRAY'
124 || $type eq 'IO' || $type eq 'CODE') {
125 return reftype($value) eq $type;
128 my $ref = reftype($value);
129 return !defined($ref) || $ref eq 'SCALAR' || $ref eq 'REF' || $ref eq 'LVALUE' || $ref eq 'REGEXP' || $ref eq 'VSTRING';
134 my ($self, $variable, $initial_value, %opts) = @_;
136 my ($name, $sigil, $type) = $self->_deconstruct_variable_name($variable);
138 my $pkg = $self->name;
141 $self->_valid_for_type($initial_value, $type)
142 || confess "$initial_value is not of type $type";
144 # cheap fail-fast check for PERLDBf_SUBLINE and '&'
145 if ($^P and $^P & 0x10 && $sigil eq '&') {
146 my $filename = $opts{filename};
147 my $first_line_num = $opts{first_line_num};
149 (undef, $filename, $first_line_num) = caller
150 if not defined $filename;
152 my $last_line_num = $opts{last_line_num} || ($first_line_num ||= 0);
154 # http://perldoc.perl.org/perldebguts.html#Debugger-Internals
155 $DB::sub{$pkg . '::' . $name} = "$filename:$first_line_num-$last_line_num";
160 no warnings 'redefine', 'misc', 'prototype';
161 *{$pkg . '::' . $name} = ref $initial_value ? $initial_value : \$initial_value;
165 my ($self, $name) = @_;
166 delete $self->namespace->{$name};
170 my ($self, $variable) = @_;
172 my ($name, $sigil, $type) = $self->_deconstruct_variable_name($variable);
174 my $namespace = $self->namespace;
176 return unless exists $namespace->{$name};
178 my $entry_ref = \$namespace->{$name};
179 if (reftype($entry_ref) eq 'GLOB') {
180 if ($type eq 'SCALAR') {
181 if (BROKEN_SCALAR_INITIALIZATION) {
182 return defined ${ *{$entry_ref}{$type} };
185 return B::svref_2object($entry_ref)->SV->isa('B::SV');
189 return defined *{$entry_ref}{$type};
193 # a symbol table entry can be -1 (stub), string (stub with prototype),
194 # or reference (constant)
195 return $type eq 'CODE';
200 my ($self, $variable, %opts) = @_;
202 my ($name, $sigil, $type) = $self->_deconstruct_variable_name($variable);
204 my $namespace = $self->namespace;
206 if (!exists $namespace->{$name}) {
208 if ($type eq 'ARRAY') {
209 if (BROKEN_ISA_ASSIGNMENT) {
212 $name eq 'ISA' ? () : ([])
216 $self->add_symbol($variable, []);
219 elsif ($type eq 'HASH') {
220 $self->add_symbol($variable, {});
222 elsif ($type eq 'SCALAR') {
223 $self->add_symbol($variable);
225 elsif ($type eq 'IO') {
226 $self->add_symbol($variable, Symbol::geniosym);
228 elsif ($type eq 'CODE') {
229 confess "Don't know how to vivify CODE variables";
232 confess "Unknown type $type in vivication";
240 my $entry_ref = \$namespace->{$name};
242 if (ref($entry_ref) eq 'GLOB') {
243 return *{$entry_ref}{$type};
246 if ($type eq 'CODE') {
248 return \&{ $self->name . '::' . $name };
256 sub get_or_add_symbol {
258 $self->get_symbol(@_, vivify => 1);
262 my ($self, $variable) = @_;
264 my ($name, $sigil, $type) = $self->_deconstruct_variable_name($variable);
267 # no doubt this is grossly inefficient and
268 # could be done much easier and faster in XS
270 my ($scalar_desc, $array_desc, $hash_desc, $code_desc, $io_desc) = (
271 { sigil => '$', type => 'SCALAR', name => $name },
272 { sigil => '@', type => 'ARRAY', name => $name },
273 { sigil => '%', type => 'HASH', name => $name },
274 { sigil => '&', type => 'CODE', name => $name },
275 { sigil => '', type => 'IO', name => $name },
278 my ($scalar, $array, $hash, $code, $io);
279 if ($type eq 'SCALAR') {
280 $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc);
281 $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc);
282 $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc);
283 $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc);
285 elsif ($type eq 'ARRAY') {
286 $scalar = $self->get_symbol($scalar_desc) if $self->has_symbol($scalar_desc) || BROKEN_SCALAR_INITIALIZATION;
287 $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc);
288 $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc);
289 $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc);
291 elsif ($type eq 'HASH') {
292 $scalar = $self->get_symbol($scalar_desc) if $self->has_symbol($scalar_desc) || BROKEN_SCALAR_INITIALIZATION;
293 $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc);
294 $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc);
295 $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc);
297 elsif ($type eq 'CODE') {
298 $scalar = $self->get_symbol($scalar_desc) if $self->has_symbol($scalar_desc) || BROKEN_SCALAR_INITIALIZATION;
299 $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc);
300 $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc);
301 $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc);
303 elsif ($type eq 'IO') {
304 $scalar = $self->get_symbol($scalar_desc) if $self->has_symbol($scalar_desc) || BROKEN_SCALAR_INITIALIZATION;
305 $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc);
306 $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc);
307 $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc);
310 confess "This should never ever ever happen";
313 $self->remove_glob($name);
315 $self->add_symbol($scalar_desc => $scalar) if defined $scalar;
316 $self->add_symbol($array_desc => $array) if defined $array;
317 $self->add_symbol($hash_desc => $hash) if defined $hash;
318 $self->add_symbol($code_desc => $code) if defined $code;
319 $self->add_symbol($io_desc => $io) if defined $io;
322 sub list_all_symbols {
323 my ($self, $type_filter) = @_;
325 my $namespace = $self->namespace;
326 return keys %{$namespace} unless defined $type_filter;
329 # or we can filter based on
330 # type (SCALAR|ARRAY|HASH|CODE)
331 if ($type_filter eq 'CODE') {
333 # any non-typeglob in the symbol table is a constant or stub
334 ref(\$namespace->{$_}) ne 'GLOB'
335 # regular subs are stored in the CODE slot of the typeglob
336 || defined(*{$namespace->{$_}}{CODE})
337 } keys %{$namespace};
339 elsif ($type_filter eq 'SCALAR') {
341 BROKEN_SCALAR_INITIALIZATION
342 ? (ref(\$namespace->{$_}) eq 'GLOB'
343 && defined(${*{$namespace->{$_}}{'SCALAR'}}))
345 my $entry = \$namespace->{$_};
346 ref($entry) eq 'GLOB'
347 && B::svref_2object($entry)->SV->isa('B::SV')
349 } keys %{$namespace};
353 ref(\$namespace->{$_}) eq 'GLOB'
354 && defined(*{$namespace->{$_}}{$type_filter})
355 } keys %{$namespace};
359 sub get_all_symbols {
360 my ($self, $type_filter) = @_;
362 my $namespace = $self->namespace;
363 return { %{$namespace} } unless defined $type_filter;
366 map { $_ => $self->get_symbol({name => $_, type => $type_filter}) }
367 $self->list_all_symbols($type_filter)
375 =item * remove_symbol also replaces the associated typeglob
377 This can cause unexpected behavior when doing manipulation at compile time -
378 removing subroutines will still allow them to be called from within the package
379 as subroutines (although they will not be available as methods). This can be
380 considered a feature in some cases (this is how L<namespace::clean> works, for
381 instance), but should not be relied upon - use C<remove_glob> directly if you
384 =item * Some minor memory leaks
386 The pure perl implementation has a couple minor memory leaks (see the TODO
387 tests in t/20-leaks.t) that I'm having a hard time tracking down - these may be
388 core perl bugs, it's hard to tell.
392 Please report any bugs through RT: email
393 C<bug-package-stash at rt.cpan.org>, or browse to
394 L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Package-Stash>.
400 =item * L<Class::MOP::Package>
402 This module is a factoring out of code that used to live here
408 You can find this documentation for this module with the perldoc command.
410 perldoc Package::Stash
412 You can also look for information at:
416 =item * AnnoCPAN: Annotated CPAN documentation
418 L<http://annocpan.org/dist/Package-Stash>
422 L<http://cpanratings.perl.org/d/Package-Stash>
424 =item * RT: CPAN's request tracker
426 L<http://rt.cpan.org/NoAuth/Bugs.html?Dist=Package-Stash>
430 L<http://search.cpan.org/dist/Package-Stash>
436 Jesse Luehrs <doy at tozt dot net>
438 Mostly copied from code from L<Class::MOP::Package>, by Stevan Little and the
443 BROKEN_ISA_ASSIGNMENT