X-Git-Url: http://git.vpit.fr/?a=blobdiff_plain;ds=inline;f=lib%2FScope%2FUpper.pm;h=40ea5c50661187f0d544950cffa4366e93d1a568;hb=06553cbfcb3bd6ccbee666625bc6b31c53320969;hp=ac97d57cd360c8d38ec77ec8436b9c2697521d17;hpb=da37c6765511d43f6a7915bc65d6b80e8f2d9217;p=perl%2Fmodules%2FScope-Upper.git
diff --git a/lib/Scope/Upper.pm b/lib/Scope/Upper.pm
index ac97d57..40ea5c5 100644
--- a/lib/Scope/Upper.pm
+++ b/lib/Scope/Upper.pm
@@ -1,5 +1,7 @@
package Scope::Upper;
+use 5.006_001;
+
use strict;
use warnings;
@@ -9,13 +11,13 @@ Scope::Upper - Act on upper scopes.
=head1 VERSION
-Version 0.18
+Version 0.30
=cut
our $VERSION;
BEGIN {
- $VERSION = '0.18';
+ $VERSION = '0.30';
}
=head1 SYNOPSIS
@@ -170,7 +172,11 @@ localize variables, array/hash values or deletions of elements in higher context
=item *
-return values immediately to an upper level with L, and know which context was in use then with L ;
+return values immediately to an upper level with L, L and L ;
+
+=item *
+
+gather information about an upper context with L and L ;
=item *
@@ -178,7 +184,7 @@ execute a subroutine in the setting of an upper subroutine stack frame with L and L.
+uniquely identify contexts with L and L.
=back
@@ -270,7 +276,10 @@ C<$key> is either an array index or a hash key, depending of which kind of varia
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
+=head2 C
+
+ localize_delete $what, $key;
+ localize_delete $what, $key, $context;
Introduces the deletion of a variable or an array/hash element delayed to the time of first return into the upper scope denoted by C<$context>.
C<$what> can be:
@@ -283,7 +292,7 @@ A glob, in which case C<$key> is ignored and the call is equivalent to C or C<'%'>, for which the call is equivalent to respectiveley C and C.
+A string beginning with C<'@'> or C<'%'>, for which the call is equivalent to respectively C and C.
=item *
@@ -295,10 +304,11 @@ C<$key> is ignored.
=head2 C
- unwind @values;
+ unwind;
unwind @values, $context;
-Returns C<@values> I the context pointed by C<$context>, i.e. from the subroutine, eval or format at or just above C<$context>, and immediately restart the program flow at this point - thus effectively returning to an upper scope.
+Returns C<@values> I the subroutine, eval or format context pointed by or just above C<$context>, and immediately restarts the program flow at this point - thus effectively returning C<@values> to an upper scope.
+If C<@values> is empty, then the C<$context> parameter is optional and defaults to the current context (making the call equivalent to a bare C) ; otherwise it is mandatory.
The upper context isn't coerced onto C<@values>, which is hence always evaluated in list context.
This means that
@@ -312,14 +322,49 @@ This means that
will set C<$num> to C<'z'>.
You can use L to handle these cases.
+=head2 C
+
+ yield;
+ yield @values, $context;
+
+Returns C<@values> I the context pointed by or just above C<$context>, and immediately restarts the program flow at this point.
+If C<@values> is empty, then the C<$context> parameter is optional and defaults to the current context ; otherwise it is mandatory.
+
+L differs from L in that it can target I upper scope (besides a C substitution context) and not necessarily a sub, an eval or a format.
+Hence you can use it to return values from a C or a C act depending on t
# $cxt = SCOPE(4), UP SUB UP SUB = UP SUB EVAL = UP CALLER(2) = TOP
...
-Where L, L and L point to depending on the C<$cxt>:
+Where L, L, L, L and L point to depending on the C<$cxt>:
sub {
eval {
sub {
{
- unwind @things => $cxt; # or uplevel { ... } $cxt;
+ unwind @things => $cxt; # or yield @things => $cxt
+ # or uplevel { ... } $cxt
...
}
...
@@ -606,9 +717,22 @@ Where L, L and L point to depending on the C<$cxt>:
# (*) Note that uplevel() will croak if you pass that scope frame,
# because it cannot target eval scopes.
+=head1 DIAGNOSTICS
+
+=head2 C
+
+This warning is emitted when L, L or L end up pointing to a context that is above the top-level context of the current stack.
+It indicates that you tried to go higher than the main scope, or to point across a C method, a signal handler, an overloaded or tied method call, a C statement or a C callback.
+In this case, the resulting context is the highest reachable one.
+
+=head2 C
+
+This warning is emitted when you ask for an L or L context and no such scope can be found in the call stack.
+The resulting context is the current one.
+
=head1 EXPORT
-The functions L, L, L, L, L, L and L are only exported on request, either individually or by the tags C<':funcs'> and C<':all'>.
+The functions L, L, L, L, L, L, L, L, L and L are only exported on request, either individually or by the tags C<':funcs'> and C<':all'>.
The constant L is also only exported on request, individually or by the tags C<':consts'> and C<':all'>.
@@ -623,7 +747,8 @@ our %EXPORT_TAGS = (
funcs => [ qw<
reap
localize localize_elem localize_delete
- unwind want_at
+ unwind yield leave
+ want_at context_info
uplevel
uid validate_uid
> ],
@@ -635,6 +760,8 @@ $EXPORT_TAGS{'all'} = [ @EXPORT_OK ];
=head1 CAVEATS
+It is not possible to act upon a scope that belongs to another perl 'stack', i.e. to target a scope across a C method, a signal handler, an overloaded or tied method call, a C statement or a C callback.
+
Be careful that local variables are restored in the reverse order in which they were localized.
Consider those examples:
@@ -682,12 +809,20 @@ when the runloop callback is replaced by another module.
In those three cases, L will look for a C statement in its callback and, if there is one, throw an exception before executing the code.
-Moreover, in order to handle C statements properly, L currently has to suffer a run-time overhead proportional to the size of the the callback in every case (with a small ratio), and proportional to the size of B the code executed as the result of the L call (including subroutine calls inside the callback) when a C statement is found in the L callback.
+Moreover, in order to handle C statements properly, L currently has to suffer a run-time overhead proportional to the size of the callback in every case (with a small ratio), and proportional to the size of B the code executed as the result of the L call (including subroutine calls inside the callback) when a C statement is found in the L callback.
Despite this shortcoming, this XS version of L should still run way faster than the pure-Perl version from L.
+Starting from C 5.19.4, it is unfortunately no longer possible to reliably throw exceptions from L'd code while the debugger is in use.
+This may be solved in a future version depending on how the core evolves.
+
=head1 DEPENDENCIES
-L (standard since perl 5.006).
+L 5.6.1.
+
+A C compiler.
+This module may happen to build with a C++ compiler as well, but don't rely on it, as no guarantee is made in this regard.
+
+L (core since perl 5.6.0).
=head1 SEE ALSO
@@ -719,17 +854,18 @@ You can find documentation for this module with the perldoc command.
perldoc Scope::Upper
-Tests code coverage report is available at L.
-
=head1 ACKNOWLEDGEMENTS
Inspired by Ricardo Signes.
+The reimplementation of a large part of this module for perl 5.24 was provided by David Mitchell.
+His work was sponsored by the Perl 5 Core Maintenance Grant from The Perl Foundation.
+
Thanks to Shawn M. Moore for motivation.
=head1 COPYRIGHT & LICENSE
-Copyright 2008,2009,2010,2011 Vincent Pit, all rights reserved.
+Copyright 2008,2009,2010,2011,2012,2013,2014,2015,2016,2017,2018 Vincent Pit, all rights reserved.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.