In message <a05111b5bb9786eae041d@[63.120.19.221]>
Dan Sugalski <[EMAIL PROTECTED]> wrote:
> At 6:58 PM +0100 8/8/02, Tom Hughes wrote:
>
> >Presumably with all keys being PMCs we will just encode the key
> >arguments in the opcode name as a k, and kc for constant keys.
>
> Yep.
>
> >Likewise, the constant keys will presumably be encoded in the byte
> >code much as specified in the PDD and then turned into PMC structures
> >in the constant table when the byte code is loaded.
>
> Yep.
One thing I just realised is that we still have a problem of how to
tell what a P register used as an key means - it can either mean that
the register contains a key, or that it contains an integer or string
that is to be used as a key.
If we're going to say that a P register is always taken to be a key
then does that mean that you can't do this:
set P0, "foo"
set P2, P1[P0]
Obviously that is manufactured, as you could do it with a constant
index or an S register but in general terms if you have perl indexing
an array or hash by a scalar then then it is likely to be indexing
one PMC by another.
If the above code was banned then you would have to build the key
dynamically instead:
new_key P0
size_key P0, 1
ke_set_value P0, 1, "foo"
set P2, P1[P0]
Or some such, depending on how the key ops wind op working, which is
something else we need to think about as the old spec I have here has
no way to set any values in the key...
Tom
--
Tom Hughes ([EMAIL PROTECTED])
http://www.compton.nu/
