X-Git-Url: http://git.vpit.fr/?a=blobdiff_plain;f=lib%2FScope%2FUpper.pm;h=4a9010059f7ce5112af17d57452539ae17458ff8;hb=3852d1e712b2e4f5c1ab14efe303ce7d7a95464d;hp=f2a97c5a5c201c9387d15c0643f5a48e405123f5;hpb=0f7334e9f0acbdac38c362be678bd6ecb658cb0b;p=perl%2Fmodules%2FScope-Upper.git
diff --git a/lib/Scope/Upper.pm b/lib/Scope/Upper.pm
index f2a97c5..4a90100 100644
--- a/lib/Scope/Upper.pm
+++ b/lib/Scope/Upper.pm
@@ -9,13 +9,13 @@ Scope::Upper - Act on upper scopes.
=head1 VERSION
-Version 0.17
+Version 0.19
=cut
our $VERSION;
BEGIN {
- $VERSION = '0.17';
+ $VERSION = '0.19';
}
=head1 SYNOPSIS
@@ -24,7 +24,10 @@ L, L, L, L and L :
package Scope;
- use Scope::Upper qw;
+ use Scope::Upper qw<
+ reap localize localize_elem localize_delete
+ :words
+ >;
sub new {
my ($class, $name) = @_;
@@ -66,22 +69,22 @@ L, L, L, L and L :
package UserLand;
{
- Scope->new("top"); # initializes $UserLand::tag
+ Scope->new("top"); # initializes $UserLand::tag
{
Scope->catch;
- my $one = 1 + undef; # prints "top: Use of uninitialized value..."
+ my $one = 1 + undef; # prints "top: Use of uninitialized value..."
{
Scope->private;
eval { require Cwd };
- print $@; # prints "Can't locate Cwd.pm in @INC (@INC contains:) at..."
- }
+ print $@; # prints "Can't locate Cwd.pm in @INC
+ } # (@INC contains:) at..."
- require Cwd; # loads Cwd.pm
+ require Cwd; # loads Cwd.pm
}
- } # prints "top: done"
+ } # prints "top: done"
L and L :
@@ -167,7 +170,7 @@ 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, and know which context was in use then with L ;
=item *
@@ -194,11 +197,18 @@ BEGIN {
XSLoader::load(__PACKAGE__, $VERSION);
}
-=head2 C
+=head2 C
+
+ reap { ... };
+ reap { ... } $context;
+ &reap($callback, $context);
Adds a destructor that calls C<$callback> (in void context) when the upper scope represented by C<$context> ends.
-=head2 C
+=head2 C
+
+ localize $what, $value;
+ localize $what, $value, $context;
Introduces a C delayed to the time of first return into the upper scope denoted by C<$context>.
C<$what> can be :
@@ -248,7 +258,10 @@ Although I believe it shouldn't be a problem as glob slots definedness is pretty
=back
-=head2 C
+=head2 C
+
+ localize_elem $what, $key, $value;
+ localize_elem $what, $key, $value, $context;
Introduces a C or C delayed to the time of first return into the upper scope denoted by C<$context>.
Unlike L, C<$what> must be a string and the type of localization is inferred from its sigil.
@@ -257,7 +270,10 @@ C<$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<$what> can be:
@@ -280,9 +296,13 @@ C<$key> is ignored.
=back
-=head2 C
+=head2 C
+
+ 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 restart the program flow at this point - thus effectively returning C<@values> to an upper scope.
+If C<@values> is empty, then the C<$context> parameter is optional and defaults to the current context (making the call equivalent to a bare C) ; otherwise it is mandatory.
The upper context isn't coerced onto C<@values>, which is hence always evaluated in list context.
This means that
@@ -296,7 +316,42 @@ This means that
will set C<$num> to C<'z'>.
You can use L to handle these cases.
-=head2 C
+=head2 C
+
+ yield;
+ yield @values, $context;
+
+Returns C<@values> I the context pointed by or just above C<$context>, and immediately restart 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, the upper context isn't coerced onto C<@values>.
+
+=head2 C
+
+ leave;
+ leave @values;
+
+Immediately returns C<@values> from the current block, whatever it may be (besides a C substitution context).
+C is actually a synonym for C, while C is a synonym for C.
+
+=head2 C
+
+ my $want = want_at;
+ my $want = want_at $context;
Like C, but for the subroutine/eval/format at or just above C<$context>.
@@ -310,9 +365,13 @@ The previous example can then be "corrected" :
will rightfully set C<$num> to C<26>.
-=head2 C
+=head2 C
+
+ my @ret = uplevel { ...; return @ret };
+ my @ret = uplevel { my @args = @_; ...; return @ret } @args, $context;
+ my @ret = &uplevel($callback, @args, $context);
-Executes the code reference C<$code> with arguments C<@args> as if it were located at the subroutine stack frame pointed by C<$context>, effectively fooling C and C into believing that the call actually happened higher in the stack.
+Executes the code reference C<$callback> with arguments C<@args> as if it were located at the subroutine stack frame pointed by C<$context>, effectively fooling C and C into believing that the call actually happened higher in the stack.
The code is executed in the context of the C call, and what it returns is returned as-is by C.
sub target {
@@ -328,6 +387,8 @@ The code is executed in the context of the C call, and what it returns
my @inverses = target(1, 2, 4); # @inverses contains (0, 0.5, 0.25)
my $count = target(1, 2, 4); # $count is 3
+Note that if C<@args> is empty, then the C<$context> parameter is optional and defaults to the current context ; otherwise it is mandatory.
+
L also implements a pure-Perl version of C.
Both are identical, with the following caveats :
@@ -379,7 +440,10 @@ A simple wrapper lets you mimic the interface of L :
Albeit the three exceptions listed above, it passes all the tests of L.
-=head2 C
+=head2 C
+
+ my $uid = uid;
+ my $uid = uid $context;
Returns an unique identifier (UID) for the context (or dynamic scope) pointed by C<$context>, or for the current context if C<$context> is omitted.
This UID will only be valid for the life time of the context it represents, and another UID will be generated next time the same scope is executed.
@@ -424,7 +488,9 @@ The UIDs are not guaranteed to be numbers, so you must use the C operator to
To check whether a given UID is valid, you can use the L function.
-=head2 C
+=head2 C
+
+ my $is_valid = validate_uid $uid;
Returns true if and only if C<$uid> is the UID of a currently valid context (that is, it designates a scope that is higher than the current one in the call stack).
@@ -458,10 +524,14 @@ True iff the module could have been built when thread-safety features.
=head3 C
+ my $top_context = TOP;
+
Returns the context that currently represents the highest scope.
=head3 C
+ my $current_context = HERE;
+
The context of the current scope.
=head2 Getting a context from a context
@@ -469,16 +539,25 @@ The context of the current scope.
For any of those functions, C<$from> is expected to be a context.
When omitted, it defaults to the the current context.
-=head3 C
+=head3 C
+
+ my $upper_context = UP;
+ my $upper_context = UP $from;
The context of the scope just above C<$from>.
-=head3 C
+=head3 C
+
+ my $sub_context = SUB;
+ my $sub_context = SUB $from;
The context of the closest subroutine above C<$from>.
Note that C<$from> is returned if it is already a subroutine context ; hence C.
-=head3 C
+=head3 C
+
+ my $eval_context = EVAL;
+ my $eval_context = EVAL $from;
The context of the closest eval above C<$from>.
Note that C<$from> is returned if it is already an eval context ; hence C.
@@ -488,11 +567,17 @@ Note that C<$from> is returned if it is already an eval context ; hence C should denote a number of scopes above the current one.
When omitted, it defaults to C<0> and those functions return the same context as L.
-=head3 C
+=head3 C
+
+ my $context = SCOPE;
+ my $context = SCOPE $level;
The C<$level>-th upper context, regardless of its type.
-=head3 C
+=head3 C
+
+ my $context = CALLER;
+ my $context = CALLER $level;
The context of the C<$level>-th upper subroutine/eval/format.
It kind of corresponds to the context represented by C, but while e.g. C refers to the caller context, C will refer to the top scope in the current context.
@@ -507,13 +592,13 @@ Where L fires depending on the C<$cxt> :
{
reap \&cleanup => $cxt;
...
- } # $cxt = SCOPE(0), or HERE
+ } # $cxt = SCOPE(0) = HERE
...
- }->(); # $cxt = SCOPE(1), or UP, or SUB, or CALLER, or CALLER(0)
+ }->(); # $cxt = SCOPE(1) = UP = SUB = CALLER(0)
...
- }; # $cxt = SCOPE(2), or UP UP, or UP SUB, or EVAL, or CALLER(1)
+ }; # $cxt = SCOPE(2) = UP UP = UP SUB = EVAL = CALLER(1)
...
- }->(); # $cxt = SCOPE(3), or SUB UP SUB, or SUB EVAL, or CALLER(2)
+ }->(); # $cxt = SCOPE(3) = SUB UP SUB = SUB EVAL = CALLER(2)
...
Where L, L and L act depending on the C<$cxt> :
@@ -523,36 +608,37 @@ Where L, L and L act depending on t
sub {
{
localize '$x' => 1 => $cxt;
- # $cxt = SCOPE(0), or HERE
+ # $cxt = SCOPE(0) = HERE
...
}
- # $cxt = SCOPE(1), or UP, or SUB, or CALLER, or CALLER(0)
+ # $cxt = SCOPE(1) = UP = SUB = CALLER(0)
...
}->();
- # $cxt = SCOPE(2), or UP UP, or UP SUB, or EVAL, or CALLER(1)
+ # $cxt = SCOPE(2) = UP UP = UP SUB = EVAL = CALLER(1)
...
};
- # $cxt = SCOPE(3), or SUB UP SUB, or SUB EVAL, or CALLER(2)
+ # $cxt = SCOPE(3) = SUB UP SUB = SUB EVAL = CALLER(2)
...
}->();
- # $cxt = SCOPE(4), UP SUB UP SUB, or UP SUB EVAL, or UP CALLER(2), or TOP
+ # $cxt = SCOPE(4), UP SUB UP SUB = UP SUB EVAL = UP CALLER(2) = TOP
...
-Where L, L and L point to depending on the C<$cxt>:
+Where L, L, L 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
...
}
...
- }->(); # $cxt = SCOPE(0 .. 1), or HERE, or UP, or SUB, or CALLER(0)
+ }->(); # $cxt = SCOPE(0) = SCOPE(1) = HERE = UP = SUB = CALLER(0)
...
- }; # $cxt = SCOPE(2), or UP UP, or UP SUB, or EVAL, or CALLER(1) (*)
+ }; # $cxt = SCOPE(2) = UP UP = UP SUB = EVAL = CALLER(1) (*)
...
- }->(); # $cxt = SCOPE(3), or SUB UP SUB, or SUB EVAL, or CALLER(2)
+ }->(); # $cxt = SCOPE(3) = SUB UP SUB = SUB EVAL = CALLER(2)
...
# (*) Note that uplevel() will croak if you pass that scope frame,
@@ -560,7 +646,7 @@ Where L, L and L point to depending on the C<$cxt>:
=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 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'>.
@@ -575,7 +661,8 @@ our %EXPORT_TAGS = (
funcs => [ qw<
reap
localize localize_elem localize_delete
- unwind want_at
+ unwind yield leave
+ want_at
uplevel
uid validate_uid
> ],
@@ -639,7 +726,12 @@ Despite this shortcoming, this XS version of L should still run way fa
=head1 DEPENDENCIES
-L (standard since perl 5.006).
+L 5.6.
+
+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 5.006).
=head1 SEE ALSO
@@ -681,7 +773,7 @@ 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 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.