Re: [Jscheme-user] internals questions.

[Geoffrey K. <ge...@kn...>]

On Jul 9, 2004, at 10:36, Ken Anderson wrote:
> Q1`:
> In src/jsint/Evaluator.java:
> public DynamicEnvironment INTERACTION_ENVIRONMENT
>
> Should this be static final, or should it be named 
> interactionEnvironment?

Would anyone ever override/replace the interaction environment?
If yes, I vote the latter.  If no, I vote the former.

> Q2: analyze()
> line 265:
>         return new DynamicVariable((Symbol)x, dynamicEnv);
> This returns a new DynamicVariable for each use of a symbol in the 
> body.
> Shouldn't it reuse one if there is one already like Symbol.intern()?  
> Though that might require a synchronized method.

By DynamicVariable I assume you mean a variable of local scope.  If 
that is true, then I think you'd want a new one for each new binding, 
as opposed to each use.  The word "dynamic" is a bit confusing to me, 
because it means one thing in the context of C or Java, another thing 
in Common Lisp.  And here we are talking about a Scheme written in 
Java.

Symbol.intern() -- wouldn't that let you have only one "x", instead of 
one at the top-level (global scope) and each lower local scope?  Or, in 
the case of (define x 1) (let ((x 2)) ...), are the two x's guaranteed 
to have different Symbols, interned separately?

Geoffrey
--
Geoffrey S. Knauth | http://knauth.org/gsk