X-Git-Url: http://git.vpit.fr/?a=blobdiff_plain;f=README;h=c6d5711fc1c48803145c44c8e5cc143497a5efa0;hb=371ac1f7b00e6de2149f97693fdcbbfe44388f43;hp=5e2fb7e35e9345a478ab473f5744fd83ab65b279;hpb=5d565c2feed583ba26f5451a0b25f1a5df2be4ed;p=perl%2Fmodules%2FScope-Upper.git diff --git a/README b/README index 5e2fb7e..c6d5711 100644 --- a/README +++ b/README @@ -2,12 +2,12 @@ NAME Scope::Upper - Act on upper scopes. VERSION - Version 0.02 + Version 0.04 SYNOPSIS package X; - use Scope::Upper qw/reap localize localize_elem/; + use Scope::Upper qw/reap localize localize_elem localize_delete/; sub desc { shift->{desc} } @@ -28,21 +28,44 @@ SYNOPSIS my $x = do { no strict 'refs'; ${$pkg.'::x'} }; # Get the $x in the scope CORE::warn($x->desc . ': ' . join('', @_)); } => 1; + + localize_delete '@ARGV', $#ARGV => 1; # delete last @ARGV element } package Y; { X::set_tag('pie'); - # $x is now a X object + # $x is now a X object, and @ARGV has one element less warn 'what'; # warns "pie: what at ..." ... } # "pie: done" is printed + package Z; + + use Scope::Upper qw/unwind want_at :words/; + + sub try (&) { + my @result = shift->(); + my $cx = SUB UP SUB; + unwind +(want_at($cx) ? @result : scalar @result) => $cx; + } + + ... + + sub zap { + try { + return @things; # returns to try() and then outside zap() + } + } + + my @what = zap(); # @what contains @things + DESCRIPTION This module lets you defer actions that will take place when the control flow returns into an upper scope. Currently, you can hook an upper scope - end, or localize variables and array/hash values in higher contexts. + end, or localize variables, array/hash values or deletions of elements + in higher contexts. FUNCTIONS "reap $callback, $level" @@ -84,13 +107,63 @@ FUNCTIONS is ; otherwise it's inferred from the sigil. $key is either an array index or a hash key, depending of which kind of variable you localize. - "TOPLEVEL" + "localize_delete $what, $key, $level" + Similiar to "localize", but for deleting variables or array/hash + elements. $what can be: + + * A glob, in which case $key is ignored and the call is equivalent to + "local *x". + + * A string beginning with '@' or '%', for which the call is equivalent + to respectiveley "local $a[$key]; delete $a[$key]" and "local + $h{$key}; delete $h{$key}". + + * A string beginning with '&', which more or less does "undef &func" + in the upper scope. It's actually more powerful, as &func won't even + "exists" anymore. $key is ignored. + + "unwind @values, $level" + Returns @values *from* the context indicated by $level, i.e. from the + subroutine, eval or format just above $level. The upper level isn't + coerced onto @values, which is hence always evaluated in list context. + + "want_at $level" + Like "wantarray", but for the subroutine/eval/format context just above + $level. + +WORDS + "TOP" Returns the level that currently represents the highest scope. + "HERE" + The current level - i.e. 0. + + "UP $from" + The level of the scope just above $from. + + "DOWN $from" + The level of the scope just below $from. + + "SUB $from" + The level of the closest subroutine context above $from. + + "EVAL $from" + The level of the closest eval context above $from. + + If $from is omitted in any of those functions, the current level is used + as the reference level. + + "CALLER $stack" + The level corresponding to the stack referenced by "caller $stack". + EXPORT - The functions "reap", "localize", "localize_elem" and "TOPLEVEL" are - only exported on request, either individually or by the tags ':funcs' - and ':all'. + The functions "reap", "localize", "localize_elem", "localize_delete", + "unwind" and "want_at" are only exported on request, either individually + or by the tags ':funcs' and ':all'. + + Same goes for the words "TOP", "HERE", "UP", "DOWN", "SUB", "EVAL" and + "CALLER" that are only exported on request, individually or by the tags + ':words' and ':all'. CAVEATS Be careful that local variables are restored in the reverse order in @@ -149,7 +222,7 @@ ACKNOWLEDGEMENTS Inspired by Ricardo Signes. COPYRIGHT & LICENSE - Copyright 2008 Vincent Pit, all rights reserved. + Copyright 2008-2009 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.