Global lexical tier

Jason Orendorff jason.orendorff at
Tue Sep 1 17:41:53 UTC 2015

On Tue, Sep 1, 2015 at 12:03 AM, Allen Wirfs-Brock wrote:
> Both the alternative suggest by Jason and the one suggest by Saam were
> considered and rejected in these discussions. It's easy to imagine a
> different semantics. It's harder to demonstrate that it is a "better
> semantics" and to get agreement on that. [...]

This is a very thorough and fair response, Allen, thanks.

> Regarding, global declarations in a REPL.  A REPL is a extra-lingual
> features. In it not covered by the language specification.  A REPL
> implementation is certainly free to define it's own rules [...]

Well, yes, but at some cost to developers, who use the REPL to inquire
into the language's behavior, right? The more modes we have, and the
more different the REPL mode is, the more often the REPL will mislead

( digress a bit, the SpiderMonkey JS shell currently defaults to
a nonstandard mode, for unrelated reasons. And it does mislead people.
I want to change it:

In any case, we're agreed that an occasional bad REPL interaction
would be no big deal on its own.


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