X-Git-Url: http://git.vpit.fr/?a=blobdiff_plain;f=lib%2FScope%2FUpper.pm;h=fc3224eea7c2df138739235f521e3f29f22793bb;hb=cf46c3456f20acba34dd6543ea76de3b84b47401;hp=4fb21d543a3f1adcfb791adf73fe7c79c144f9c5;hpb=e4bb8d889bcaaf2a3c9f1f9cd2a8185115db5db0;p=perl%2Fmodules%2FScope-Upper.git diff --git a/lib/Scope/Upper.pm b/lib/Scope/Upper.pm index 4fb21d5..fc3224e 100644 --- a/lib/Scope/Upper.pm +++ b/lib/Scope/Upper.pm @@ -9,20 +9,20 @@ Scope::Upper - Act on upper scopes. =head1 VERSION -Version 0.05 +Version 0.06 =cut our $VERSION; BEGIN { - $VERSION = '0.05'; + $VERSION = '0.06'; } =head1 SYNOPSIS package X; - use Scope::Upper qw/reap localize localize_elem localize_delete/; + use Scope::Upper qw/reap localize localize_elem localize_delete :words/; sub desc { shift->{desc} } @@ -30,21 +30,22 @@ BEGIN { my ($desc) = @_; # First localize $x so that it gets destroyed last - localize '$x' => bless({ desc => $desc }, __PACKAGE__) => 1; + localize '$x' => bless({ desc => $desc }, __PACKAGE__) => UP; # one scope 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"; - } => 1; + } => SCOPE 1; # same as UP here 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 CALLER 0; # same as UP here - localize_delete '@ARGV', $#ARGV => 1; # delete last @ARGV element + # delete last @ARGV element + localize_delete '@ARGV', -1 => UP SUB HERE; # same as UP here } package Y; @@ -84,6 +85,15 @@ You can also return to an upper level and know which context was in use then. =head1 FUNCTIONS +In all those functions, C<$context> refers to the target scope. + +You have to use one or a combination of L to build the C<$context> to pass to these functions. +This is needed in order to ensure that the module still works when your program is ran in the debugger. +Don't try to use a raw value or things will get messy. + +The only thing you can assume is that it is an I indicator of the frame. +This means that you can safely store it at some point and use it when needed, and it will still denote the original scope. + =cut BEGIN { @@ -91,13 +101,13 @@ BEGIN { XSLoader::load(__PACKAGE__, $VERSION); } -=head2 C +=head2 C -Add a destructor that calls C<$callback> when the C<$level>-th upper scope ends, where C<0> corresponds to the current scope. +Add a destructor that calls C<$callback> when the upper scope represented by C<$context> ends. -=head2 C +=head2 C -A C delayed to the time of first return into the C<$level>-th upper scope. +A C delayed to the time of first return into the upper scope denoted by C<$context>. C<$what> can be : =over 4 @@ -114,7 +124,7 @@ A string beginning with a sigil, representing the symbol to localize and to assi If the sigil is C<'$'>, L follows the same syntax as C, i.e. C<$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. @@ -122,19 +132,19 @@ Other sigils (C<'@'>, C<'%'>, C<'&'> and C<'*'>) require C<$value> to be a refer When the symbol is given by a string, it is resolved when the actual localization takes place and not when C is called. This means that - sub tag { localize '$x', $_[0] => 1; } + sub tag { localize '$x', $_[0] => UP } will localize in the caller's namespace. =back -=head2 C +=head2 C Similar to L but for array and hash elements. If C<$what> is a glob, the slot to fill is determined from which type of reference C<$value> is ; otherwise it's inferred from the sigil. C<$key> is either an array index or a hash key, depending of which kind of variable you localize. -=head2 C +=head2 C Similiar to L, but for deleting variables or array/hash elements. C<$what> can be: @@ -157,77 +167,82 @@ C<$key> is ignored. =back -=head2 C +=head2 C -Returns C<@values> I the context indicated by C<$level>, i.e. from the subroutine, eval or format just above C<$level>. +Returns C<@values> I the context pointed by C<$context>, i.e. from the subroutine, eval or format just above C<$context>. -The upper level isn't coerced onto C<@values>, which is hence always evaluated in list context. +The upper context isn't coerced onto C<@values>, which is hence always evaluated in list context. This means that my $num = sub { my @a = ('a' .. 'z'); - unwind @a => 0; + unwind @a => HERE; }->(); will set C<$num> to C<'z'>. You can use L to handle these cases. -=head2 C +=head2 C -Like C, but for the subroutine/eval/format context just above C<$level>. +Like C, but for the subroutine/eval/format just above C<$context>. The previous example can then be "corrected" : 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>. =head1 WORDS -=head2 C +=head2 Constants -Returns the level that currently represents the highest scope. +=head3 C -=head2 C +Returns the context that currently represents the highest scope. -The current level - i.e. C<0>. +=head3 C -=head2 C +The context of the current scope. -The level of the scope just above C<$from>. +=head2 Getting a context from a context -=head2 C +For any of those functions, C<$from> is expected to be a context. +When omitted, it defaults to the the current context. -The level of the scope just below C<$from>. +=head3 C -=head2 C +The context of the scope just above C<$from>. -The level of the closest subroutine context above C<$from>. +=head3 C -=head2 C +The context of the closest subroutine above C<$from>. -The level of the closest eval context above C<$from>. +=head3 C -If C<$from> is omitted in any of those functions, the current level is used as the reference level. +The context of the closest eval above C<$from>. -=head2 C +=head2 Getting a context from a level -The level of the C<$stack>-th upper subroutine/eval/format context. -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. -For example, +Here, C<$level> should denote a number of scopes above the current one. +When omitted, it defaults to C<0> and those functions return the same context as L. - reap ... => CALLER(0) +=head3 C -will fire the destructor when the current subroutine/eval/format ends. +The C<$level>-th upper context, regardless of its type. + +=head3 C + +The context of the C<$level>-th upper subroutine/eval/format. +It kind of corresponds to the context represented by C, but while e.g. C refers to the caller context, C will refer to the top scope in the current context. =head1 EXPORT The functions L, L, L, L, L and L are only exported on request, either individually or by the tags C<':funcs'> and C<':all'>. -Same goes for the words L, L, L, L, L, L and L that are only exported on request, individually or by the tags C<':words'> and C<':all'>. +Same goes for the words L, L, L, L, L, L and L that are only exported on request, individually or by the tags C<':words'> and C<':all'>. =cut @@ -236,7 +251,7 @@ use base qw/Exporter/; our @EXPORT = (); our %EXPORT_TAGS = ( funcs => [ qw/reap localize localize_elem localize_delete unwind want_at/ ], - words => [ qw/TOP HERE UP DOWN SUB EVAL CALLER/ ], + words => [ qw/TOP HERE UP SUB EVAL SCOPE CALLER/ ], ); our @EXPORT_OK = map { @$_ } values %EXPORT_TAGS; $EXPORT_TAGS{'all'} = [ @EXPORT_OK ]; @@ -248,7 +263,7 @@ Consider those examples: local $x = 0; { - reap sub { print $x } => 0; + reap sub { print $x } => HERE; local $x = 1; ... } @@ -256,7 +271,7 @@ Consider those examples: ... { local $x = 1; - reap sub { $x = 2 } => 0; + reap sub { $x = 2 } => HERE; ... } # $x is 0 @@ -266,6 +281,9 @@ The first case is "solved" by moving the C before the C, and the se L, L and L effects can't cross C blocks, hence calling those functions in C is deemed to be useless. This is an hopeless case because C blocks are executed once while localizing constructs should do their job at each run. +Some rare oddities may still happen when running inside the debugger. +It may help to use a perl higher than 5.8.9 or 5.10.0, as they contain some context fixes. + =head1 DEPENDENCIES L (standard since perl 5.006). @@ -296,6 +314,8 @@ Tests code coverage report is available at L