[plt-scheme] (typeof obj)

On Jun 11, 2007, at 10:13 AM, Robby Findler wrote:

> On 6/11/07, Robert Nikander <nikander at nc.rr.com> wrote:
>>
>> The problem I have with your example above is that it won't work as
>> new types are added.
>
> Structs are the way to add new types to mzscheme :)

Ah, I get it...  I was assuming that C-level extensions could define  
new "primitive" non-struct types.  So if there is a small list of  
type predicates that covers all possible values, I guess `run-time- 
type' is not necessary like in some other languages.

But I then have the same question about structs -- how do I get the  
struct type info from a struct value.  But for that, I have yet to  
consult the help desk...

thanks,
Rob