On 11/11/11 20:18, Phil Clayton wrote:
I am currently implementing
type t
val null : t
val isNull : t -> bool
where type t = CInterface.vol. There is no problem doing this but I
wondered whether I could improve the CInterface structure to avoid
annoying little C library functions.
I have realized that C functions are not necessary to implement these -
just to toClong and fromClong:
val null = toClong 0
fun isNull v = fromClong v = 0
Would it be at all controversial to include
null : vol
in CInterface?
For a different reason, this could still be useful. I had forgotten
that volatiles do not persist in saved states or executables (it should
have been obvious from the name) so I can't see how to create such a
null value to implement
val null : t
where type t = CInterface.vol. (There is nothing volatile about null
really.)
Perhaps the best approach here is to implement with type t =
CInterface.vol option, with NONE representing null.
Phil
_______________________________________________
polyml mailing list
polyml@inf.ed.ac.uk
http://lists.inf.ed.ac.uk/mailman/listinfo/polyml
