=head1 VERSION
-Version 0.09
+Version 0.10
=cut
our $VERSION;
BEGIN {
- $VERSION = '0.09';
+ $VERSION = '0.10';
}
=head1 SYNOPSIS
=head2 C<reap $callback, $context>
-Add a destructor that calls C<$callback> (in void context) when the upper scope represented by C<$context> ends.
+Adds a destructor that calls C<$callback> (in void context) when the upper scope represented by C<$context> ends.
=head2 C<localize $what, $value, $context>
-A C<local> delayed to the time of first return into the upper scope denoted by C<$context>.
+Introduces a C<local> delayed to the time of first return into the upper scope denoted by C<$context>.
C<$what> can be :
=over 4
Other sigils (C<'@'>, C<'%'>, C<'&'> and C<'*'>) require C<$value> to be a reference of the corresponding type.
When the symbol is given by a string, it is resolved when the actual localization takes place and not when C<localize> is called.
-This means that
+Thus, if the symbol name is not qualified, it will refer to the variable in the package where the localization actually takes place and not in the one where the C<localize> call was compiled.
+For example,
+
+ {
+ package Scope;
+ sub new { localize '$tag', $_[0] => UP }
+ }
+
+ {
+ package Tool;
+ {
+ Scope->new;
+ ...
+ }
+ }
- sub tag { localize '$x', $_[0] => UP }
+will localize C<$Tool::tag> and not C<$Scope::tag>.
+If you want the other behaviour, you just have to specify C<$what> as a glob or a qualified name.
-will localize in the caller's namespace.
+Note that if C<$what> is a string denoting a variable that wasn't declared beforehand, the relevant slot will be vivified as needed and won't be deleted from the glob when the localization ends.
+This situation never arises with C<local> because it only compiles when the localized variable is already declared.
+Although I believe it shouldn't be a problem as glob slots definedness is pretty much an implementation detail, this behaviour may change in the future if proved harmful.
=back
=head2 C<localize_elem $what, $key, $value, $context>
-Similar to L</localize> but for array and hash elements.
-If C<$what> is a glob, the slot to fill is determined from which type of reference C<$value> is ; otherwise it's inferred from the sigil.
+Introduces a C<local $what[$key] = $value> or C<local $what{$key} = $value> delayed to the time of first return into the upper scope denoted by C<$context>.
+Just like for L</localize>, the type of localization is determined from which kind of reference C<$value> is when C<$what> is a glob, and from the sigil when it's a string.
C<$key> is either an array index or a hash key, depending of which kind of variable you localize.
+If C<$what> is a string pointing to an undeclared variable, the variable will be vivified as soon as the localization occurs and emptied when it ends, although it will still exist in its glob.
+
=head2 C<localize_delete $what, $key, $context>
-Similiar to L</localize>, but for deleting variables or array/hash elements.
+Introduces the deletion of a variable or an array/hash element delayed to the time of first return into the upper scope denoted by C<$context>.
C<$what> can be:
=over 4
=head2 C<unwind @values, $context>
-Returns C<@values> I<from> the context pointed by C<$context>, i.e. from the subroutine, eval or format just above C<$context>, and immediately restart the program flow at this point - thus effectively returning to (or from, depending on how you see it) an upper context.
+Returns C<@values> I<from> the context pointed by C<$context>, i.e. from the subroutine, eval or format at or just above C<$context>, and immediately restart the program flow at this point - thus effectively returning to an upper scope.
The upper context isn't coerced onto C<@values>, which is hence always evaluated in list context.
This means that
=head2 C<want_at $context>
-Like C<wantarray>, but for the subroutine/eval/format just above C<$context>.
+Like C<wantarray>, but for the subroutine/eval/format at or just above C<$context>.
The previous example can then be "corrected" :
L<Alias>, L<Hook::Scope>, L<Scope::Guard>, L<Guard>.
+L<Continuation::Escape> is a thin wrapper around L<Scope::Upper> that gives you a continuation passing style interface to L</unwind>.
+It's easier to use, but it requires you to have control over the scope where you want to return.
+
=head1 AUTHOR
Vincent Pit, C<< <perl at profvince.com> >>, L<http://www.profvince.com>.
=head1 BUGS
-Please report any bugs or feature requests to C<bug-scope-upper at rt.cpan.org>, or through the web interface at L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Scope-Upper>. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.
+Please report any bugs or feature requests to C<bug-scope-upper at rt.cpan.org>, or through the web interface at L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Scope-Upper>.
+I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.
=head1 SUPPORT
projects / perl / modules / Scope-Upper.git / blobdiff