Scope::Upper - Act on upper scopes.
VERSION
- Version 0.18
+ Version 0.19
SYNOPSIS
"reap", "localize", "localize_elem", "localize_delete" and "WORDS" :
which means that you can safely store it at some point and use it when
needed, and it will still denote the original scope.
- "reap $callback, $context"
+ "reap"
+ reap { ... };
+ reap { ... } $context;
+ &reap($callback, $context);
+
Adds a destructor that calls $callback (in void context) when the upper
scope represented by $context ends.
- "localize $what, $value, $context"
+ "localize"
+ localize $what, $value;
+ localize $what, $value, $context;
+
Introduces a "local" delayed to the time of first return into the upper
scope denoted by $context. $what can be :
implementation detail, this behaviour may change in the future if
proved harmful.
- "localize_elem $what, $key, $value, $context"
+ "localize_elem"
+ localize_elem $what, $key, $value;
+ localize_elem $what, $key, $value, $context;
+
Introduces a "local $what[$key] = $value" or "local $what{$key} =
$value" delayed to the time of first return into the upper scope denoted
by $context. Unlike "localize", $what must be a string and the type of
in the upper scope. It's actually more powerful, as &func won't even
"exists" anymore. $key is ignored.
- "unwind @values, $context"
+ "unwind"
+ unwind @values;
+ unwind @values, $context;
+
Returns @values *from* the context pointed by $context, i.e. from the
subroutine, eval or format at or just above $context, and immediately
restart the program flow at this point - thus effectively returning to
will set $num to 'z'. You can use "want_at" to handle these cases.
- "want_at $context"
+ "want_at"
+ my $want = want_at;
+ my $want = want_at $context;
+
Like "wantarray", but for the subroutine/eval/format at or just above
$context.
will rightfully set $num to 26.
"uplevel $code, @args, $context"
+ my @ret = uplevel { ...; return @ret };
+ my @ret = uplevel { my @args = @_; ...; return @ret } @args;
+ my @ret = uplevel { ... } @args, $context;
+ my @ret = &uplevel($callback, @args, $context);
+
Executes the code reference $code with arguments @args as if it were
located at the subroutine stack frame pointed by $context, effectively
fooling "caller" and "die" into believing that the call actually
Albeit the three exceptions listed above, it passes all the tests of
Sub::Uplevel.
- "uid $context"
+ "uid"
+ my $uid = uid;
+ my $uid = 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
To check whether a given UID is valid, you can use the "validate_uid"
function.
- "validate_uid $uid"
+ "validate_uid"
+ my $is_valid = 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).
WORDS
Constants
"TOP"
+ my $top_context = TOP;
+
Returns the context that currently represents the highest scope.
"HERE"
+ my $current_context = HERE;
+
The context of the current scope.
Getting a context from a context
For any of those functions, $from is expected to be a context. When
omitted, it defaults to the the current context.
- "UP $from"
+ "UP"
+ my $upper_context = UP;
+ my $upper_context = UP $from;
+
The context of the scope just above $from.
- "SUB $from"
+ "SUB"
+ my $sub_context = SUB;
+ my $sub_context = SUB $from;
+
The context of the closest subroutine above $from. Note that $from is
returned if it is already a subroutine context ; hence "SUB SUB == SUB".
- "EVAL $from"
+ "EVAL"
+ my $eval_context = EVAL;
+ my $eval_context = EVAL $from;
+
The context of the closest eval above $from. Note that $from is returned
if it is already an eval context ; hence "EVAL EVAL == EVAL".
When omitted, it defaults to 0 and those functions return the same
context as "HERE".
- "SCOPE $level"
+ "SCOPE"
+ my $context = SCOPE;
+ my $context = SCOPE $level;
+
The $level-th upper context, regardless of its type.
- "CALLER $level"
+ "CALLER"
+ my $context = CALLER;
+ my $context = CALLER $level;
+
The context of the $level-th upper subroutine/eval/format. It kind of
corresponds to the context represented by "caller $level", but while
e.g. "caller 0" refers to the caller context, "CALLER 0" will refer to
Thanks to Shawn M. Moore for motivation.
COPYRIGHT & LICENSE
- Copyright 2008,2009,2010,2011 Vincent Pit, all rights reserved.
+ Copyright 2008,2009,2010,2011,2012 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.
projects / perl / modules / Scope-Upper.git / commitdiff