[VPM] About that AUTOLOAD thing...

[Peter Scott]

At 11:15 PM 4/12/2003 -0700, nkuipers wrote:
>...which I slammed.  I stand corrected, apparently.  The April issue of Linux
>Mag has an article on Eclipse, and one of the features mentioned is 'In this
>example, the method you're trying to call doesn't exist, so the "quick 
>fix" is
>to create the method.  The tip even provides a stub...that will be created 
>for
>you...invaluable because it allows you to write code in a top-down fashion.'
>
>So there you have it.

There's a bit of apples and oranges here.  From your description, this 
article appears to be describing a venerated method of just-in-time method 
creation; instead of writing a bunch of accessor methods, you put a list of 
the allowed ones in a hash and then to avoid creating unnecessary ones, 
create them on demand, something like (may be typos):

sub AUTOLOAD {
   (my $method = our $AUTOLOAD) =~ s/.*://;
   return if $method eq 'DESTROY';
   croak "Invalid method $method" unless $METHOD{$method};
   no strict 'refs';
   *$method = sub { my $self = shift; $self->{$method} = shift if @_; 
$self->{method} };
   goto &$method;
}

Whereas the suggestion mooted here was to prompt the user to enter the 
code... which gives me the willies.  I guess something like this, perhaps:

sub AUTOLOAD {
   (my $method = our $AUTOLOAD) =~ s/.*://;
   return if $method eq 'DESTROY';
   croak "Invalid method $method" unless $METHOD{$method};
   print "Enter code for sub $method: ";
   local $/;
   my $code = <STDIN>;
   no strict 'refs';
   *$method = eval "sub { $code }";
   goto &$method;
}

although can you read another method from STDIN after already seeing 
end-of-file for the first one...?
--
Peter Scott
peter at psdt.com
http://www.perldebugged.com