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Diffstat (limited to 'lib/mauve.pm')
| -rw-r--r-- | lib/mauve.pm | 161 |
1 files changed, 0 insertions, 161 deletions
diff --git a/lib/mauve.pm b/lib/mauve.pm deleted file mode 100644 index e94a412940..0000000000 --- a/lib/mauve.pm +++ /dev/null @@ -1,161 +0,0 @@ -package mauve; -use base qw/Exporter/; -@EXPORT_OK=qw(reftype refaddr blessed isweak weaken); -1; -# mauve routines are installed from universal.c -__END__ - -=head1 NAME - -mauve - utilities for introspecting properties of scalar variables - -=head1 SYNOPSIS - - # mauve routines are "always loaded" - my $type = mauve::reftype($var); - my $addr = mauve::refaddr($var); - my $class = mauve::blessed($var); - - my $ref= \@foo; - mauve::weaken($ref); - my $isweak= mauve::isweak($ref); - - # import mauve routines into your namespace - use mauve qw(reftype refaddr blessed weaken isweak); - -=head1 DESCRIPTION - -The C<mauve> namespace is a perl internals reserved namespace for utility -routines relating to scalar variables. These routines are closely related -to the like named routines in Scalar::Util except that they are always loaded -and where it makes sense, return FALSE instead of 'undef'. - -=head2 reftype SCALAR - -Returns false if the argument is not a reference, otherwise returns the -reference type, which will be one of the following values: - -=over 4 - -=item VSTRING - -Has special v-string magic - -=item REF - -Is a reference to another ref (C<< $$ref >>) - -=item SCALAR - -Is a reference to a scalar (C<< $$scalar >>) - -=item LVALUE - -An lvalue reference - B<NOTE>, tied lvalues appear to be of type C<SCALAR> -for backwards compatibility reasons - -=item ARRAY - -An array reference (C<< @$array >>) - -=item HASH - -A hash reference (C<< %$hash >>) - -=item CODE - -A subroutine reference (C<< $code->() >>) - -=item GLOB - -A reference to a glob (C<< *$glob >>) - -=item FORMAT - -A format reference (C<< *IO{FORMAT} >>) - -=item IO - -An IO reference (C<< *STDOUT{IO} >>) - -=item BIND - -A bind reference - -=item REGEXP - -An executable regular expression (C<< qr/../ >>) - -=item UNKNOWN - -This should never be seen - -=back - -=head2 refaddr SCALAR - -Returns false if the argument is not a reference, otherwise returns the -address of the reference as an unsigned integer. - -=head2 blessed SCALAR - -Returns false if the argument is not a blessed reference, otherwise returns -the package name the reference was blessed into. - -=head2 weaken REF - -REF will be turned into a weak reference. This means that it will not -hold a reference count on the object it references. Also when the reference -count on that object reaches zero, REF will be set to undef. - -This is useful for keeping copies of references , but you don't want to -prevent the object being DESTROY-ed at its usual time. - - { - my $var; - $ref = \$var; - weaken($ref); # Make $ref a weak reference - } - # $ref is now undef - -Note that if you take a copy of a scalar with a weakened reference, -the copy will be a strong reference. - - my $var; - my $foo = \$var; - weaken($foo); # Make $foo a weak reference - my $bar = $foo; # $bar is now a strong reference - -This may be less obvious in other situations, such as C<grep()>, for instance -when grepping through a list of weakened references to objects that may have -been destroyed already: - - @object = grep { defined } @object; - -This will indeed remove all references to destroyed objects, but the remaining -references to objects will be strong, causing the remaining objects to never -be destroyed because there is now always a strong reference to them in the -@object array. - -=head2 isweak EXPR - -If EXPR is a scalar which is a weak reference the result is true. - - $ref = \$foo; - $weak = isweak($ref); # false - weaken($ref); - $weak = isweak($ref); # true - -B<NOTE>: Copying a weak reference creates a normal, strong, reference. - - $copy = $ref; - $weak = isweak($copy); # false - -=head1 SEE ALSO - -L<Scalar::Util> - -=cut - - - |