On Sat, Mar 9, 2013 at 6:48 AM, Igor Stasenko <siguctua at gmail.com> wrote:


> Well, maybe it's an overkill .. it is mainly about speed and reusing
> VM's lookup mechanism
> for searching a name over multiple scopes (when you have namespaces
> with imports).
>
> On a first run, you will replace
> "read value of <binding>" bytecode with " send #value to <binding>"
> but that implies having a binding at compile time (you must lookup for
> a name at compile time).
> It also means that you won't change anything semantically: even though
> you sending a message,
> you still accessing the very same state which you bound early at compile
> time.
>

Right. The lookup happens at compile time. When the method is actually
executed, we're just fetching the value from the binding we found at
compile time. I don't see how that's going to be slow. In the most common
case, a class reference, it's not even a message send, because we have a
dedicated bytecode. For global variables, it'll be two message sends: we
send #value to the alias binding, which then sends #value on to the
canonical binding in the environment's "contents" dictionary.

Then, i wonder, if such change is actually worth doing. Because if you
> don't do lookup dynamically,
> then there is no change.
>

Sure there is. We still bind names at compile time, but we have changed the
way names are resolved.

Colin
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