Re: typechecking

[Marius Vollmer]

Han-Wen Nienhuys <address@hidden> writes:

> address@hidden writes:
>> >>    
>> >>
>> >
>> >It would be interesting to see if we could map the Scheme semantics
>> >(true = !SCM_BOOL_F) to C. That would require mapping SCM_BOOL_F to
>> >(void*)0x0. Is this desirable, and does anyone see a possibility for this?
>> >
>> SCM values, where the 3 least significant bits are zero indicate 
>> non-immediates. That is, the SCM value can without any modification be 
>
> I understand the tag system, so I'm aware of the
> implications. However, I was wondering whether such a change stands a
> chance of being incorporated, if it would work.

I find it quite tempting to make SCM_BOOL_F identical to 0; it will
prevent a lot of bugs.  But I do think it is better to not gurantee
anything like this about the SCM type (except that you can assign it
directly).

A properly abstract interface to SCM values is a good thing, even if
it is inconvenient at times.

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