[chuck-users] incorrect compiler error
signal.automatique at gmail.com
Wed Feb 3 19:06:02 EST 2010
On 4 February 2010 00:38, Michael Heuer <heuermh at gmail.com> wrote:
> The following appears to be a bug in the compiler
I agree. The order of definitions for classes and -global scope- functions
shouldn't matter yet it does with regard to extending. It will also muck up
in some cases where the parser incorrectly misses that functions refer to
things not yet instantiated, something that I suspect is a separate but
closely related issue that should instead yield a warning from the parser.
IMHO this is a bug as the specs don't ever refer to this order mattering at
all, though I could see how we might demand placing "class bar extends foo"
below "class foo". Apparently this bug can also affect the type-system in
how it deals with the type of returned objects when those extend other
types. When it doesn't you'll find the objects don't have the member
functions you added when extending and will get a error for that.
We may by now wonder whether there is anything that *doesn't* affect the
type of returned objects of a type that extends another ;-). Your workaround
is what I suggest (and use) as well and so far that seems stable to me. You
might be able to get around this by casting up and down for a bit but I tend
to reserve that for emergencies as typically it leads to very fragile code.
It also tends to lead to headaches and cursing for me.
So; yes, a bug. Or more like two that now turn out to interact. Let's hope
they are not each other's type.
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