Re: Complex contagion

[Raymond T. <toy...@gm...>]

Sam Steingold wrote:
>> * Raymond Toy <gbl.enlzbaq@tznvy.pbz> [2008-11-26 19:49:25 -0500]:
>>     
>>> on a second thought (and the first reading of
>>> http://www.lispworks.com/documentation/HyperSpec/Body/f_comp_2.htm),
>>> clisp is fine.
>>> clisp extends the COMPLEX type to hold different types in real and
>>> imaginary parts, and the behavior you observe is consistent with this
>>> extension.
>>> note that COMPLEX is permitted to return a rational (not a complex), so
>>>
>>> (let ((x (complex 0)))
>>>   (check-type x complex))
>>>
>>> will signal an error in a compliant implementation.
>>>
>>>       
>> But the section on complex says complex returns either a rational or a
>> complex.  (complex 0.0) returns neither.
>>     
>
> yes, and if ANSI CL supported (complex float rational), it would have
> said that COMPLEX returns a real or a complex.
>   
This is makes sense.
> what I am trying to say is that what you observe is a part of the CLISP
> (COMPLEX t t) type extension which is hard to make optional - about as
> hard as ripping out the arbitrary precision floats, and about as useful.
>   
Wouldn't most of the issues be fixed just by making COMPLEX apply float
contagion on the components?

> however, in keeping with out ANSI compliance commitment,
>   
"out" or "our"?

Ray