[plt-scheme] v299 FFI question

> Also - when I define an enum: (define en (_enum '(a b c))) - how do I
> access the enumerated elements?


Hi Yoav,

Wherever a function expects a enumerated type value like 'en', we can pass
one of the symbols in the enumeration.  The enum type should magically
translate between the symbols and the integers.  For example, if we have
an enumeration like:

  (define _mysql-field-type
    (_enum '(decimal
             tiny
             short
             long
             float
             double
             null
             ...))

and if we had a C function that returned an element of that enumeration,
from the mzscheme end of things, we'll get back symbols like 'decimal and
'double that are transparently translated from the C ints 0 and 5.

Hope this helps!