Re: [Chicken-users] handling the undefined value

[F. Wittenberger]

Am Donnerstag, den 25.11.2010, 22:34 +0100 schrieb Felix:
> From: Jörg "F. Wittenberger" <address@hidden>
> Subject: Re: [Chicken-users] handling the undefined value
> Date: Thu, 25 Nov 2010 16:24:01 +0100
> 
> > Am Mittwoch, den 24.11.2010, 18:53 +0100 schrieb Felix:
> >> From: Jörg "F. Wittenberger" <address@hidden>
> >> Subject: Re: [Chicken-users] handling the undefined value
> >> Date: Mon, 22 Nov 2010 15:08:46 +0100
> >> 
> >> > Have a compiler switch (since it may break some code), which changes the
> >> > code to return zero values instead of the distinguished undefined value.
> >> 
> >> I don't think this is a great idea: this will change the
> >> semantics of code using call-with-values,
> > 
> > So far I did not come around to test, whether or not I'll be able to
> > find my undefined value with the new scrutinizer version.
> 
> Unfortunately I had to disable this feature again. We probably need
> some sort of "style" warning switch (there are too many places where
> procedures without result or undefined result use forms like `when').

Sadly.

The "style" warning I'd like to avoid if all possible.

I'd rather vote for changing the syntax definitions (one-by-one, tell me
the git/svn/wtf reference and I'll try my best).

> > This however I don't understand.  Why would it be less efficient to call
> > a continuation with zero instead of one value?
> 
> There is a bit of wrapping and result-value count checking going on
> behind the scenes in that case.

I see.  I understand: could be as efficient, but that would need quite a
lot of other changes.  Right?