From: Vincent Pit Date: Fri, 16 Jan 2009 23:43:34 +0000 (+0100) Subject: Doc update X-Git-Tag: v0.06~2 X-Git-Url: http://git.vpit.fr/?a=commitdiff_plain;h=9a258ccdcca73cc6ca9470c06e7db103c3ba8193;p=perl%2Fmodules%2FScope-Upper.git Doc update --- diff --git a/lib/Scope/Upper.pm b/lib/Scope/Upper.pm index 45bdbe2..988254f 100644 --- a/lib/Scope/Upper.pm +++ b/lib/Scope/Upper.pm @@ -22,7 +22,7 @@ BEGIN { package X; - use Scope::Upper qw/reap localize localize_elem localize_delete UP/; + 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 => $desc }, __PACKAGE__) => UP; + localize '$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"; - } => UP; + } => 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('', @_)); - } => UP; + } => UP CALLER 0; # same as UP here - localize_delete '@ARGV', $#ARGV => UP; # delete last @ARGV element + # delete last @ARGV element + localize_delete '@ARGV', -1 => UP SUB HERE; # same as UP here } package Y; @@ -82,42 +83,16 @@ This module lets you defer actions that will take place when the control flow re Currently, you can hook an upper scope end, or localize variables, array/hash values or deletions of elements in higher contexts. You can also return to an upper level and know which context was in use then. -=head1 WORDS - -These control words are to be used to indicate the target scope. - -=head2 C - -Returns the level that currently represents the highest scope. - -=head2 C - -The current level. - -=head2 C - -The level of the scope just above C<$from>. - -=head2 C - -The level of the closest subroutine context above C<$from>. - -=head2 C - -The level of the closest eval context above C<$from>. - -If C<$from> is omitted in any of those functions, the current level is used as the reference level. - -=head2 C - -The C<$stack>-th upper frame. +=head1 FUNCTIONS -=head2 C +In all those functions, C<$context> refers to the target scope. -The level of the C<$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. +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. -=head1 FUNCTIONS +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 @@ -126,13 +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 @@ -163,13 +138,13 @@ 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: @@ -192,11 +167,11 @@ 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 $num = sub { @@ -207,9 +182,9 @@ This means that will set C<$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" : @@ -220,6 +195,49 @@ The previous example can then be "corrected" : will righteously set C<$num> to C<26>. +=head1 WORDS + +=head2 Constants + +=head3 C + +Returns the context that currently represents the highest scope. + +=head3 C + +The context of the current scope. + +=head2 Getting a context from a context + +For any of those functions, C<$from> is expected to be a context. +When omitted, it defaults to the the current context. + +=head3 C + +The context of the scope just above C<$from>. + +=head3 C + +The context of the closest subroutine above C<$from>. + +=head3 C + +The context of the closest eval above C<$from>. + +=head2 Getting a context from a level + +Here, C<$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. + +=head3 C + +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'>. @@ -263,6 +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). @@ -293,6 +314,8 @@ Tests code coverage report is available at L{desc} } @@ -21,15 +23,16 @@ sub set_tag { my $pkg = caller; my $x = do { no strict 'refs'; ${$pkg.'::x'} }; # Get the $x in the scope print $x->desc . ": done\n"; - } => UP; + } => 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('', @_)); - } => UP; + } => UP CALLER 0; # same as UP here - localize_delete '@ARGV', $#ARGV => UP; # delete last @ARGV element + # delete last @ARGV element + localize_delete '@ARGV', -1 => UP SUB HERE; # same as UP here } package main; @@ -41,4 +44,5 @@ use warnings; X::set_tag('pie'); # $x is now a X object, and @ARGV has one element less warn 'what'; # warns "pie: what at ..." + warn "\@ARGV contains [@ARGV]"; } # "pie: done" is printed