From: Vincent Pit Date: Mon, 10 Oct 2011 20:50:59 +0000 (+0200) Subject: This is 0.18 X-Git-Tag: v0.18^0 X-Git-Url: http://git.vpit.fr/?p=perl%2Fmodules%2FScope-Upper.git;a=commitdiff_plain;h=70187dc24bb0f90a81f58ff2bd52ba7d9c3ac06f This is 0.18 --- diff --git a/Changes b/Changes index 9eeadad..6a27bd6 100644 --- a/Changes +++ b/Changes @@ -1,5 +1,17 @@ Revision history for Scope-Upper +0.18 2011-10-10 20:50 UTC + + Add : The uid() function returns an unique identifier for each dynamic + scope. The validate_uid() function can be used to check whether + one such identifier is valid (i.e. that the scope it refers to + is still alive). + + Chg : It is no longer possible on perl 5.6 to call goto() in an + uplevel callback to replace the uplevel call. This change was + needed in order to ensure consistency between platforms + regarding to the following fix just below. + + Fix : The uplevel() tests now pass on Windows. + Thanks C.H. Kang for bringing this to my attention. + 0.17 2011-10-03 21:45 UTC + Fix : uplevel() will now use the correct pad when executing its callback. This fixes at least two issues : diff --git a/META.json b/META.json index 746f43c..d32dc6e 100644 --- a/META.json +++ b/META.json @@ -57,5 +57,5 @@ "url" : "http://git.profvince.com/?p=perl%2Fmodules%2FScope-Upper.git" } }, - "version" : "0.17" + "version" : "0.18" } diff --git a/META.yml b/META.yml index 36c1da1..80f4c8d 100644 --- a/META.yml +++ b/META.yml @@ -32,4 +32,4 @@ resources: homepage: http://search.cpan.org/dist/Scope-Upper/ license: http://dev.perl.org/licenses/ repository: http://git.profvince.com/?p=perl%2Fmodules%2FScope-Upper.git -version: 0.17 +version: 0.18 diff --git a/README b/README index faa4a76..7d441b7 100644 --- a/README +++ b/README @@ -2,14 +2,17 @@ NAME Scope::Upper - Act on upper scopes. VERSION - Version 0.17 + Version 0.18 SYNOPSIS "reap", "localize", "localize_elem", "localize_delete" and "WORDS" : package Scope; - use Scope::Upper qw; + use Scope::Upper qw< + reap localize localize_elem localize_delete + :words + >; sub new { my ($class, $name) = @_; @@ -51,22 +54,22 @@ SYNOPSIS package UserLand; { - Scope->new("top"); # initializes $UserLand::tag + Scope->new("top"); # initializes $UserLand::tag { Scope->catch; - my $one = 1 + undef; # prints "top: Use of uninitialized value..." + my $one = 1 + undef; # prints "top: Use of uninitialized value..." { Scope->private; eval { require Cwd }; - print $@; # prints "Can't locate Cwd.pm in @INC (@INC contains:) at..." - } + print $@; # prints "Can't locate Cwd.pm in @INC + } # (@INC contains:) at..." - require Cwd; # loads Cwd.pm + require Cwd; # loads Cwd.pm } - } # prints "top: done" + } # prints "top: done" "unwind" and "want_at" : @@ -113,6 +116,28 @@ SYNOPSIS target('hello'); # "hello from Uplevel::target()" + "uid" and "validate_uid" : + + use Scope::Upper qw; + + my $uid; + + { + $uid = uid(); + { + if ($uid eq uid(UP)) { # yes + ... + } + if (validate_uid($uid)) { # yes + ... + } + } + } + + if (validate_uid($uid)) { # no + ... + } + DESCRIPTION This module lets you defer actions *at run-time* that will take place when the control flow returns into an upper scope. Currently, you can: @@ -127,7 +152,9 @@ DESCRIPTION which context was in use then with "want_at" ; * execute a subroutine in the setting of an upper subroutine stack - frame with "uplevel". + frame with "uplevel" ; + + * uniquely identify contextes with "uid" and "validate_uid". FUNCTIONS In all those functions, $context refers to the target scope. @@ -325,6 +352,78 @@ FUNCTIONS Albeit the three exceptions listed above, it passes all the tests of Sub::Uplevel. + "uid $context" + Returns an unique identifier (UID) for the context (or dynamic scope) + pointed by $context, or for the current context if $context is omitted. + This UID will only be valid for the life time of the context it + represents, and another UID will be generated next time the same scope + is executed. + + my $uid; + + { + $uid = uid; + if ($uid eq uid()) { # yes, this is the same context + ... + } + { + if ($uid eq uid()) { # no, we are one scope below + ... + } + if ($uid eq uid(UP)) { # yes, UP points to the same scope as $uid + ... + } + } + } + + # $uid is now invalid + + { + if ($uid eq uid()) { # no, this is another block + ... + } + } + + For example, each loop iteration gets its own UID : + + my %uids; + + for (1 .. 5) { + my $uid = uid; + $uids{$uid} = $_; + } + + # %uids has 5 entries + + The UIDs are not guaranteed to be numbers, so you must use the "eq" + operator to compare them. + + To check whether a given UID is valid, you can use the "validate_uid" + function. + + "validate_uid $uid" + Returns true if and only if $uid is the UID of a currently valid context + (that is, it designates a scope that is higher than the current one in + the call stack). + + my $uid; + + { + $uid = uid(); + if (validate_uid($uid)) { # yes + ... + } + { + if (validate_uid($uid)) { # yes + ... + } + } + } + + if (validate_uid($uid)) { # no + ... + } + CONSTANTS "SU_THREADSAFE" True iff the module could have been built when thread-safety features. @@ -375,13 +474,13 @@ WORDS { reap \&cleanup => $cxt; ... - } # $cxt = SCOPE(0), or HERE + } # $cxt = SCOPE(0) = HERE ... - }->(); # $cxt = SCOPE(1), or UP, or SUB, or CALLER, or CALLER(0) + }->(); # $cxt = SCOPE(1) = UP = SUB = CALLER(0) ... - }; # $cxt = SCOPE(2), or UP UP, or UP SUB, or EVAL, or CALLER(1) + }; # $cxt = SCOPE(2) = UP UP = UP SUB = EVAL = CALLER(1) ... - }->(); # $cxt = SCOPE(3), or SUB UP SUB, or SUB EVAL, or CALLER(2) + }->(); # $cxt = SCOPE(3) = SUB UP SUB = SUB EVAL = CALLER(2) ... Where "localize", "localize_elem" and "localize_delete" act depending on @@ -392,19 +491,19 @@ WORDS sub { { localize '$x' => 1 => $cxt; - # $cxt = SCOPE(0), or HERE + # $cxt = SCOPE(0) = HERE ... } - # $cxt = SCOPE(1), or UP, or SUB, or CALLER, or CALLER(0) + # $cxt = SCOPE(1) = UP = SUB = CALLER(0) ... }->(); - # $cxt = SCOPE(2), or UP UP, or UP SUB, or EVAL, or CALLER(1) + # $cxt = SCOPE(2) = UP UP = UP SUB = EVAL = CALLER(1) ... }; - # $cxt = SCOPE(3), or SUB UP SUB, or SUB EVAL, or CALLER(2) + # $cxt = SCOPE(3) = SUB UP SUB = SUB EVAL = CALLER(2) ... }->(); - # $cxt = SCOPE(4), UP SUB UP SUB, or UP SUB EVAL, or UP CALLER(2), or TOP + # $cxt = SCOPE(4), UP SUB UP SUB = UP SUB EVAL = UP CALLER(2) = TOP ... Where "unwind", "want_at" and "uplevel" point to depending on the $cxt: @@ -413,15 +512,15 @@ WORDS eval { sub { { - unwind @things => $cxt; # or uplevel { ... } $cxt; + unwind @things => $cxt; # or uplevel { ... } $cxt; ... } ... - }->(); # $cxt = SCOPE(0 .. 1), or HERE, or UP, or SUB, or CALLER(0) + }->(); # $cxt = SCOPE(0) = SCOPE(1) = HERE = UP = SUB = CALLER(0) ... - }; # $cxt = SCOPE(2), or UP UP, or UP SUB, or EVAL, or CALLER(1) (*) + }; # $cxt = SCOPE(2) = UP UP = UP SUB = EVAL = CALLER(1) (*) ... - }->(); # $cxt = SCOPE(3), or SUB UP SUB, or SUB EVAL, or CALLER(2) + }->(); # $cxt = SCOPE(3) = SUB UP SUB = SUB EVAL = CALLER(2) ... # (*) Note that uplevel() will croak if you pass that scope frame, @@ -472,9 +571,16 @@ CAVEATS may help to use a perl higher than 5.8.9 or 5.10.0, as they contain some context-related fixes. - Calling "goto" to replace an "uplevel"'d code frame does not work when a - custom runloop is used or when debugging flags are set with "perl -D". - In those two cases, "uplevel" will look for a "goto &sub" statement in + Calling "goto" to replace an "uplevel"'d code frame does not work : + + * for a "perl" older than the 5.8 series ; + + * for a "DEBUGGING" "perl" run with debugging flags set (as in "perl + -D ...") ; + + * when the runloop callback is replaced by another module. + + In those three cases, "uplevel" will look for a "goto &sub" statement in its callback and, if there is one, throw an exception before executing the code. diff --git a/lib/Scope/Upper.pm b/lib/Scope/Upper.pm index 7ebfca3..b5936db 100644 --- a/lib/Scope/Upper.pm +++ b/lib/Scope/Upper.pm @@ -9,13 +9,13 @@ Scope::Upper - Act on upper scopes. =head1 VERSION -Version 0.17 +Version 0.18 =cut our $VERSION; BEGIN { - $VERSION = '0.17'; + $VERSION = '0.18'; } =head1 SYNOPSIS