"Simon Marlow" <[EMAIL PROTECTED]> wrote:
> > I thought yhc supported unboxed values, so a loop like
> >
> > count 0 = 0
> > count n = count (n - 1)
> >
> > count 100000
> >
> > could block the runtime (assuming it was properly unboxed by the
> > compiler) since it never calls back into it and is just a straight
> > up countdown loop?
>
> are we talking about the same compiler? YHC is fully interpreted, has
> no unboxed types, and AFAIK it is impossible to write any code that
> doesn't get preempted after a while.
Indeed. But unboxing is not the issue - the main reason is that yhc
cannot currently compile that code into a loop - jumps only go forwards
in the bytecode, never backwards. The only possible bytecode
representation of a loop is as a recursive call, which immediately
presents an opportunity to insert a yield.
Regards,
Malcolm
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