Re: How do I make object methods callable as non-OO functions?

[jhourcle]

I use the following at the beginning of the sub, so I can still use $self, and someone can override the functions in a derived class, if need be. (it won't work with your exact calling syntax though, as it's mostly for items that don't require values from the actual object).

sub function_name {
    # for a function call
    my $self = __PACKAGE__;
    # for a method call
    $self = shift if UNIVERSAL::isa( $_[0], __PACKAGE__ );
    ...
}

You could also write do the shorter, more efficient, but potentially more confusing :

sub function_name {
    my $self = UNIVERSAL::isa( $_[0], __PACKAGE__ )
        ? shift : __PACKAGE__;
    ...
}

[cazz]

CGI.pm does something simliar, except with a generic sub.

sub self_or_default {
    return @_ if defined($_[0]) && (!ref($_[0])) &&($_[0] eq 'CGI');
    unless (defined($_[0]) &&
        (ref($_[0]) eq 'CGI' || UNIVERSAL::isa($_[0],'CGI')) # slightl
+y optimized for common case 
        ) {
    $Q = $CGI::DefaultClass->new unless defined($Q);
    unshift(@_,$Q);
    }
    return wantarray ? @_ : $Q;
}

Then they use it like this:

sub url_param {
    my ($self,@p) = self_or_default(@_);
    my $name = shift(@p);
    return undef unless exists($ENV{QUERY_STRING});
...