Subj : Re: anyone know of a language where nonexistent functions return
To   : comp.programming
From : Jonathan Bartlett
Date : Fri Jul 22 2005 12:01 pm

pantagruel wrote:
>  An existent function calling such a nonexistent function would
> basically be left with an empty string, unless the programmer defined
> specific error generation. Theoretical literature welcome. hope this is
> a reasonable question to ask here
> 

Perl can do this and more (it can actually dynamically generate the 
given function at runtime).  If you define AUTOLOAD, it will be called 
for non-existant functions in the current package.  So if you have a 
program like this:

sub AUTOLOAD
{
	return "";
}

$test = foo();

This does what you want.  Even better, you can have stuff like this 
(adapted from the Perl documentation):

sub AUTOLOAD
{
	my $name = our $AUTOLOAD;
	*$AUTOLOAD = sub { return "You were calling $name\n"; }
	goto &$AUTOLOAD;
}

$a = foo(); #$a now has "You were calling foo\n"
$b = eee(); #$b now has "You were calling eee\n"
$c = foo(); #same as above, but now that foo() is loaded, it doesn't 
call autoload any more

Jon
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