hmm ... you are going to extremes now. :)

so

->mutate(FIELD) is a getter for FIELD

->mutate(FIELD,VALUE) is a setter for FIELD

->mutate(FILED,VALUE,OTHER...) shouldn't compile

I think, in this particular case you can still apply a prototype of ($;$) together with the signature ($field,@values)

At least theoretically, not sure if it's still implemented that way.

UPDATE

well not with methods, see other post:

Wait a second....

If you are talking about compile-time checking a ->method I'm pretty sure that this can't be done in dynamically typed languages like Perl.

Like with prototypes I expect this only to be possible with normal subs. ( without static typing of the $obj it's impossible to tell which ->methods are allowed, normal subs OTOH can be pre-declared.)

And when doing a dynamic check at run-time, using a @slurpy array is just good enough.

If you are talking about compile-time checking ...

No, I'm not talking about compile-time checking. I want method call checking at runtime. My sig_lexical example does what I want, but I'm not sure if this is a legal usage.

Greetings,
-jo

$gryYup$d0ylprbpriprrYpkJl2xyl~rzg??P~5lp2hyl0p$

> I want method call checking at runtime

I can't follow anymore.

You want 1 argument for a setter, and 0 arguments for a getter.

Hence you need a conditional check anyway.

So use a @slurpy parameter and check the size at runtime.

Then die "too many arguments" if @slurpy > 1

Problem solved.

Cheers Rolf
_{(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery}