I recall reading somewhere (can't find it now) that Moscow ML is incorrect, but that it was done deliberately for efficiency reasons, the thinking being that it would be unlikely to be an issue in practice.
That is (as I recall), in f x1 x2 x3 (f not an application) it will evaluate _all_ the arguments before evaluating _any_ of the applications
Peter - is this correct ?
Regards,
Jeremy Dawson
Ivan Tomac wrote:
Is the following code supposed to print 1 followed by 2 or 2 followed by 1?
val _ = (fn () => (print "1\n"; fn x => x)) () (print "2\n"; ())
In SML/NJ, MLton and PolyML it does the former, while in Moscow ML it does the latter. Is this specified somewhere in the standard? I noticed equivalent code in OCaml behaves the way Moscow ML does which is not very surprising seeing how Moscow ML was based on Caml Light. Could this be a bug in Moscow ML?
The following code works the same in all 4 SML compilers (but different in OCaml):
val _ = (print "1\n"; 1) + (print "2\n"; 2)
It seems to me like SML/NJ, MLton and PolyML evaluate all function arguments left to right, OCaml evaluates them right to left, and Moscow ML seems inconsistent. _______________________________________________ polyml mailing list polyml@inf.ed.ac.uk http://lists.inf.ed.ac.uk/mailman/listinfo/polyml