I find there is a lack of C API functions for dereferencing non-aggregate pointer types. There already exist enough of them to write workarounds for the missing functionality, but I think these should be builtin so we don't have to resort to such hacks to get a basic feature. What I think would good to add is:
1) "get-pointer" which dereferences a pointer to a pointer, thus returning the address its argument points to.
2) An integer constant which is equal to "sizeof(void *)" for the platform the interpreter is running on.
3) "get-short" which dereferences a pointer to a short int, thus returning the 16 bit integer its argument points to.
4) An unsigned variant of all the functions that currently dereference a pointer to a signed integer.
These all add features which I think are essential to having the ability to interface with more C libraries. I also noticed the interface only has a function for derefencing double-precision floating point. While I don't often see floating point used, especially pointers to floating point, I would think for completeness that there should also be functions to handle pointers to "float" and "long double". Thank you.
As long as these are not available you could use unpack for all signed and unsigned types. E.g. for a definition of get-short:
> (define (get-short addr) (first (unpack "u" addr)))
(lambda (addr) (first (unpack "u" addr)))
> (get-short (pack "u" 12345))
12345
>
And a short expression for pointer size: