Introduce SCOPE()

[perl/modules/Scope-Upper.git] / lib / Scope / Upper.pm

diff --git a/lib/Scope/Upper.pm b/lib/Scope/Upper.pm
index 4fb21d543a3f1adcfb791adf73fe7c79c144f9c5..45bdbe2a1c494aa10a72fe875bebdd259490e079 100644 (file)
--- a/lib/Scope/Upper.pm
+++ b/lib/Scope/Upper.pm
@@ -22,7 +22,7 @@ BEGIN {
 
     package X;
 
 
     package X;
 

-    use Scope::Upper qw/reap localize localize_elem localize_delete/;
+    use Scope::Upper qw/reap localize localize_elem localize_delete UP/;

 
     sub desc { shift->{desc} }
 
 
     sub desc { shift->{desc} }
 


@@ -30,21 +30,21 @@ BEGIN {
      my ($desc) = @_;
 
      # First localize $x so that it gets destroyed last
      my ($desc) = @_;
 
      # First localize $x so that it gets destroyed last

-     localize '$x' => bless({ desc => $desc }, __PACKAGE__) => 1;
+     localize '$x' => bless({ desc => $desc }, __PACKAGE__) => UP;

 
      reap sub {
       my $pkg = caller;
       my $x = do { no strict 'refs'; ${$pkg.'::x'} }; # Get the $x in the scope
       print $x->desc . ": done\n";
 
      reap sub {
       my $pkg = caller;
       my $x = do { no strict 'refs'; ${$pkg.'::x'} }; # Get the $x in the scope
       print $x->desc . ": done\n";

-     } => 1;
+     } => UP;

 
      localize_elem '%SIG', '__WARN__' => sub {
       my $pkg = caller;
       my $x = do { no strict 'refs'; ${$pkg.'::x'} }; # Get the $x in the scope
       CORE::warn($x->desc . ': ' . join('', @_));
 
      localize_elem '%SIG', '__WARN__' => sub {
       my $pkg = caller;
       my $x = do { no strict 'refs'; ${$pkg.'::x'} }; # Get the $x in the scope
       CORE::warn($x->desc . ': ' . join('', @_));

-     } => 1;
+     } => UP;

 
 

-     localize_delete '@ARGV', $#ARGV => 1; # delete last @ARGV element
+     localize_delete '@ARGV', $#ARGV => UP; # delete last @ARGV element

     }
 
     package Y;
     }
 
     package Y;


@@ -82,6 +82,41 @@ This module lets you defer actions that will take place when the control flow re
 Currently, you can hook an upper scope end, or localize variables, array/hash values or deletions of elements in higher contexts.
 You can also return to an upper level and know which context was in use then.
 
 Currently, you can hook an upper scope end, or localize variables, array/hash values or deletions of elements in higher contexts.
 You can also return to an upper level and know which context was in use then.
 

+=head1 WORDS
+
+These control words are to be used to indicate the target scope.
+
+=head2 C<TOP>
+
+Returns the level that currently represents the highest scope.
+
+=head2 C<HERE>
+
+The current level.
+
+=head2 C<UP $from>
+
+The level of the scope just above C<$from>.
+
+=head2 C<SUB $from>
+
+The level of the closest subroutine context above C<$from>.
+
+=head2 C<EVAL $from>
+
+The level of the closest eval context above C<$from>.
+
+If C<$from> is omitted in any of those functions, the current level is used as the reference level.
+
+=head2 C<SCOPE $stack>
+
+The C<$stack>-th upper frame.
+
+=head2 C<CALLER $stack>
+
+The level of the C<$stack>-th upper subroutine/eval/format context.
+It kind of corresponds to the context represented by C<caller $stack>, but while e.g. C<caller 0> refers to the caller context, C<CALLER 0> will refer to the top scope in the current context.
+

 =head1 FUNCTIONS
 
 =cut
 =head1 FUNCTIONS
 
 =cut


@@ -114,7 +149,7 @@ A string beginning with a sigil, representing the symbol to localize and to assi
 If the sigil is C<'$'>, L</localize> follows the same syntax as C<local $x = $value>, i.e. C<$value> isn't dereferenced.
 For example,
 
 If the sigil is C<'$'>, L</localize> follows the same syntax as C<local $x = $value>, i.e. C<$value> isn't dereferenced.
 For example,
 

-    localize '$x', \'foo' => 0;
+    localize '$x', \'foo' => HERE;

 
 will set C<$x> to a reference to the string C<'foo'>.
 Other sigils (C<'@'>, C<'%'>, C<'&'> and C<'*'>) require C<$value> to be a reference of the corresponding type.
 
 will set C<$x> to a reference to the string C<'foo'>.
 Other sigils (C<'@'>, C<'%'>, C<'&'> and C<'*'>) require C<$value> to be a reference of the corresponding type.


@@ -122,7 +157,7 @@ Other sigils (C<'@'>, C<'%'>, C<'&'> and C<'*'>) require C<$value> to be a refer
 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
 
 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
 

-    sub tag { localize '$x', $_[0] => 1; }
+    sub tag { localize '$x', $_[0] => UP }

 
 will localize in the caller's namespace.
 
 
 will localize in the caller's namespace.
 


@@ -166,7 +201,7 @@ This means that
 
     my $num = sub {
      my @a = ('a' .. 'z');
 
     my $num = sub {
      my @a = ('a' .. 'z');

-     unwind @a => 0;
+     unwind @a => HERE;

     }->();
 
 will set C<$num> to C<'z'>.
     }->();
 
 will set C<$num> to C<'z'>.


@@ -180,54 +215,16 @@ The previous example can then be "corrected" :
 
     my $num = sub {
      my @a = ('a' .. 'z');
 
     my $num = sub {
      my @a = ('a' .. 'z');

-     unwind +(want_at(0) ? @a : scalar @a) => 0;
+     unwind +(want_at(HERE) ? @a : scalar @a) => HERE;

     }->();
 
 will righteously set C<$num> to C<26>.
 
     }->();
 
 will righteously set C<$num> to C<26>.
 

-=head1 WORDS
-
-=head2 C<TOP>
-
-Returns the level that currently represents the highest scope.
-
-=head2 C<HERE>
-
-The current level - i.e. C<0>.
-
-=head2 C<UP $from>
-
-The level of the scope just above C<$from>.
-
-=head2 C<DOWN $from>
-
-The level of the scope just below C<$from>.
-
-=head2 C<SUB $from>
-
-The level of the closest subroutine context above C<$from>.
-
-=head2 C<EVAL $from>
-
-The level of the closest eval context above C<$from>.
-
-If C<$from> is omitted in any of those functions, the current level is used as the reference level.
-
-=head2 C<CALLER $stack>
-
-The level of the C<$stack>-th upper subroutine/eval/format context.
-It kind of corresponds to the context represented by C<caller $stack>, but while e.g. C<caller 0> refers to the caller context, C<CALLER 0> will refer to the top scope in the current context.
-For example,
-
-    reap ... => CALLER(0)
-
-will fire the destructor when the current subroutine/eval/format ends.
-

 =head1 EXPORT
 
 The functions L</reap>, L</localize>, L</localize_elem>, L</localize_delete>,  L</unwind> and L</want_at> are only exported on request, either individually or by the tags C<':funcs'> and C<':all'>.
 
 =head1 EXPORT
 
 The functions L</reap>, L</localize>, L</localize_elem>, L</localize_delete>,  L</unwind> and L</want_at> are only exported on request, either individually or by the tags C<':funcs'> and C<':all'>.
 

-Same goes for the words L</TOP>, L</HERE>, L</UP>, L</DOWN>, L</SUB>, L</EVAL> and L</CALLER> that are only exported on request, individually or by the tags C<':words'> and C<':all'>.
+Same goes for the words L</TOP>, L</HERE>, L</UP>, L</SUB>, L</EVAL>, L</SCOPE> and L</CALLER> that are only exported on request, individually or by the tags C<':words'> and C<':all'>.

 
 =cut
 
 
 =cut
 


@@ -236,7 +233,7 @@ use base qw/Exporter/;
 our @EXPORT      = ();
 our %EXPORT_TAGS = (
  funcs => [ qw/reap localize localize_elem localize_delete unwind want_at/ ],
 our @EXPORT      = ();
 our %EXPORT_TAGS = (
  funcs => [ qw/reap localize localize_elem localize_delete unwind want_at/ ],

- words => [ qw/TOP HERE UP DOWN SUB EVAL CALLER/ ],
+ words => [ qw/TOP HERE UP SUB EVAL SCOPE CALLER/ ],

 );
 our @EXPORT_OK   = map { @$_ } values %EXPORT_TAGS;
 $EXPORT_TAGS{'all'} = [ @EXPORT_OK ];
 );
 our @EXPORT_OK   = map { @$_ } values %EXPORT_TAGS;
 $EXPORT_TAGS{'all'} = [ @EXPORT_OK ];


@@ -248,7 +245,7 @@ Consider those examples:
 
     local $x = 0;
     {
 
     local $x = 0;
     {

-     reap sub { print $x } => 0;
+     reap sub { print $x } => HERE;

      local $x = 1;
      ...
     }
      local $x = 1;
      ...
     }


@@ -256,7 +253,7 @@ Consider those examples:
     ...
     {
      local $x = 1;
     ...
     {
      local $x = 1;

-     reap sub { $x = 2 } => 0;
+     reap sub { $x = 2 } => HERE;

      ...
     }
     # $x is 0
      ...
     }
     # $x is 0