Re: [Sbcl-help] ftype declarations for generic functions

[Nicolas N. <Nic...@iw...>]

Henrik Motakef <use...@he...> writes:

> Hi,
> 
> Is it possible and/or meaningfull to declare the ftype of a generic
> function? It looks like in sbcl (0.8.5), a form like
> 
> (defgeneric foo (x y))
> 
> automatically implies a declaration like
> 
> (ftype (function (t t) *) foo)
> 
> overriding any previous explicit declaration, and issuing a style
> warning about it if they don't match (which they usually don't). Is
> there a way to declare a more strict type for a gf, so that ideally I
> would get neat warning for methods that obviously don't conform to it
> like I would get for ordinary functions?

I think for gfs a combination of types would be the most reasonable type
declaration, e.g. (or (function (string) fixnum) (function (list) fixnum)).
To be practically usable, this should probably adapt dynamically to new
method definitions...

Nicolas.