Re: [Chicken-hackers] [PATCH] Fix #1620 by ignoring captured state of replaced variables

[felix . winkelmann]

> I had a look at #1620 and as far as I can tell there's no reason why
> an aliased variable cannot be marked as replaceable when either the
> alias or the variable it aliases are captured.
>
> Captured simply means that it needs to be wrapped up in the closure,
> AFAIK.  But if it's replaced, then the original variable will need
> to end up in the closure.  The only case where you can't replace is
> if either variable is assigned to, because then they don't point to
> the same thing anymore.
>
> I've tested several eggs with this and it seems to work fine.  The
> test case in #1620 is now compiled similar to the version with manually
> inserted eq? calls.
>

Yes, this appears to be the correct way - I wondered why there was not
an additional constraint on assignment, but since the order of optimizations
is not easily seen in advance, one has to be careful about many assumptions.

I think your reasing is correct, but must ask everybody to let me review this 
for
a certain time before we commit this patch.


felix