Re^2: Variable Name Mistery. Who calls?

What I want is: I'm working on a module to allow me create objects on the fly (I know there are a bunch of cpan modules that does exactly the same and better, but I was wondering how would that be, and also considered that a good learning experience) The point is that I'm using something like this (On my main class):

sub AUTOLOAD {
    my $_call = our $AUTOLOAD;
    $_call =~ s/.*:://;
    my $self = shift;
    my $param = shift;
    ...
    $self->{$_call} = $_param || return $self->{$_call};
}
[download]

So far, so good. But the problem is, that at some point, when I initialize a 'new' object, I define for it a list of available parameters, which will be then used as that object method. So, what I want is to raise a warning when I try to do something like

my $o = Foo->new(); #create new object
$o->Available_Param_List(["one", "two"]); #methods that should be avai
+lable to $o
$o->one('this will work ok');
$o->nope('this should print a warn on saying that nope is not availabl
+e for $o');
[download]

I want to avoid things like passing the var name to the constructor function or things like that... Thats why I been thinking that *maybe* there was a way to know the name of the variable that called to a package.

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Re^3: Variable Name Mistery. Who calls? by ikegami (Patriarch) on Oct 25, 2006 at 19:16 UTC
The traditional message is `Can't locate object method "nope" via package "Foo" (perhaps you forgo +t to load "Foo"?) at file.pl line 4.` [download] Why won't the following suffice? `Can't locate object method "nope" (perhaps you forgot to specify "nope +" to Available_Param_List) at file.pl line 4.` [download] Chances are you won't be calling `nope` more than one time per line, so you'll know exactly which object is giving the error. Use Carp's `croak` to make the message appear to originate from the calling line.	[reply] [d/l] [select]
Re^3: Variable Name Mistery. Who calls? by cephas (Pilgrim) on Oct 25, 2006 at 19:26 UTC
#!/usr/bin/perl my $o = Foo->new(); $o->available_methods([ qw/one two/]); $o->one("This will work\n"); $o->two("This will work as well\n"); $o->three("This won't work\n"); package Foo; use Carp; my %Objs; sub new { my $self = {}; $Objs{$self} = {}; bless $self, shift; } sub available_methods { my($self,$methods_ref) = @_; $Objs{$self}{methods} = $methods_ref; } sub DESTROY { my $self = shift; delete $Objs{$self}; } sub AUTOLOAD { my $_call = our $AUTOLOAD; $_call =~ s/.*:://; my $self = shift; my $param = shift; if(grep /$_call/,@{ $Objs{$self}{methods} }) { print $param; } else { carp("Couldn't execute $_call\n"); } } [download]	[reply] [d/l]
Re^4: Variable Name Mistery. Who calls? by porta (Sexton) on Oct 25, 2006 at 22:17 UTC
It's almost there. this is the output I've got: ~$ perl p.pl This will work This will work as well Couldn't execute three at p.pl line 9 And, what I want to achieve is to print (for example) which variable raised that warning. Something like this: Couldn't execute three on $o at p.pl line 9 Perhaps am I asking to much?	[reply]
Re^5: Variable Name Mistery. Who calls? by ikegami (Patriarch) on Oct 26, 2006 at 02:19 UTC
Well, you could use PadWalker's `var_name`. `var_name` won't always work, though. Before using PadWalker, ask yourself if you really think the tiny bit of extra usefulness to help debug the rare situation where a non-existant function is called more than once in a given statement is really worth the extra work, complexity and maintenance issues of displaying the variable's name (when there might not even be one).	[reply] [d/l] [select]
Re^3: Variable Name Mistery. Who calls? by ysth (Canon) on Oct 26, 2006 at 00:01 UTC
`my $param = shift; ... $self->{$_call} = $_param \|\| return $self->{$_call};` [download] I assume $param and $_param were supposed to be the same. That's a little obfuscated, and doesn't allow setting parameters to false values. A more typical way to do it is: `# (after shifting everything but param) if (@_) { return $self->{$_call} = shift; } else { return $self->{$_call}; }` [download]	[reply] [d/l] [select]