X-Git-Url: http://git.vpit.fr/?a=blobdiff_plain;f=lib%2FScope%2FUpper.pm;h=7553492c3bde6d88189582c33be7c70f34b70a7c;hb=0441a0ad6e426898c4424b48bff13716b5657757;hp=ac97d57cd360c8d38ec77ec8436b9c2697521d17;hpb=da37c6765511d43f6a7915bc65d6b80e8f2d9217;p=perl%2Fmodules%2FScope-Upper.git diff --git a/lib/Scope/Upper.pm b/lib/Scope/Upper.pm index ac97d57..7553492 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 0.23 =cut our $VERSION; BEGIN { - $VERSION = '0.18'; + $VERSION = '0.23'; } =head1 SYNOPSIS @@ -170,7 +172,11 @@ localize variables, array/hash values or deletions of elements in higher context =item * -return values immediately to an upper level with L, and know which context was in use then with L ; +return values immediately to an upper level with L, L and L ; + +=item * + +gather information about an upper context with L and L ; =item * @@ -178,7 +184,7 @@ execute a subroutine in the setting of an upper subroutine stack frame with L and L. +uniquely identify contexts with L and L. =back @@ -270,7 +276,10 @@ C<$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 block : + + my $now = do { + local $@; + eval { require Time::HiRes } or yield time() => HERE; + Time::HiRes::time(); + }; + + my @uniq = map { + yield if $seen{$_}++; # returns the empty list from the block + ... + } @things; + +Like for L, the upper context isn't coerced onto C<@values>. +You can use the fifth value returned by L to handle context coercion. + +=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. + +Like for L, you can use the fifth value returned by L to handle context coercion. + =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>. +Like L, but for the subroutine, eval or format context located at or just above C<$context>. -The previous example can then be "corrected" : +It can be used to revise the example showed in L : my $num = sub { my @a = ('a' .. 'z'); @@ -329,14 +374,72 @@ The previous example can then be "corrected" : will rightfully set C<$num> to C<26>. -=head2 C +=head2 C + + my ($package, $filename, $line, $subroutine, $hasargs, + $wantarray, $evaltext, $is_require, $hints, $bitmask, + $hinthash) = context_info $context; + +Gives information about the context denoted by C<$context>, akin to what L provides but not limited only to subroutine, eval and format contexts. +When C<$context> is omitted, it defaults to the current context. + +The returned values are, in order : + +=over 4 + +=item * + +I<(index 0)> : the namespace in use when the context was created ; + +=item * + +I<(index 1)> : the name of the file at the point where the context was created ; + +=item * + +I<(index 2)> : the line number at the point where the context was created ; + +=item * + +I<(index 3)> : the name of the subroutine called for this context, or C if this is not a subroutine context ; + +=item * + +I<(index 4)> : a boolean indicating whether a new instance of C<@_> was set up for this context, or C if this is not a subroutine context ; + +=item * + +I<(index 5)> : the context (in the sense of L) in which the context (in our sense) is executed ; + +=item * + +I<(index 6)> : the contents of the string being compiled for this context, or C if this is not an eval context ; + +=item * + +I<(index 7)> : a boolean indicating whether this eval context was created by C, or C if this is not an eval context ; + +=item * + +I<(index 8)> : the value of the lexical hints in use when the context was created ; + +=item * + +I<(index 9)> : a bit string representing the warnings in use when the context was created ; + +=item * + +I<(index 10)> : a reference to the lexical hints hash in use when the context was created (only on perl 5.10 or greater). + +=back + +=head2 C my @ret = uplevel { ...; return @ret }; - my @ret = uplevel { my @args = @_; ...; return @ret } @args; - my @ret = uplevel { ... } @args, $context; + 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 { @@ -352,6 +455,8 @@ 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 : @@ -500,7 +605,7 @@ 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. +When omitted, it defaults to the current context. =head3 C @@ -586,13 +691,14 @@ Where L, L and L 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 { ... } $cxt ... } ... @@ -608,7 +714,7 @@ Where L, L and L point to depending on the C<$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, 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 +729,8 @@ 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 > ], @@ -682,12 +789,17 @@ 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. =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 @@ -729,7 +841,7 @@ Thanks to Shawn M. Moore for motivation. =head1 COPYRIGHT & LICENSE -Copyright 2008,2009,2010,2011 Vincent Pit, all rights reserved. +Copyright 2008,2009,2010,2011,2012,2013 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.