[E-Lang] Syntax change: reducing side-effects

Mark S. Miller markm@caplet.com
Tue, 13 Feb 2001 10:42:11 -0800

At 10:28 AM Tuesday 2/13/01, Bill Frantz wrote:
>But on further thought, it is already being treated differently.  The inner
>scopes are the stored program.  They can be recalled and executed again and
>again.  On the other hand, the outer scope is the stream-of-conscience
>program, which is not stored.  Once it has been executed, the only way to
>execute it again is to enter (cut/paste) it again.

Very well put.

>Perhaps there is some
>way of unifying these two special treatments.

Definitely worth thinking about.  

A quick note that will remain mysterious until I explain Value Normal Form 
vs Slot Normal Form:

A way to view the conflict I recently noticed between the mechanics of the 
top level interactive scope and the Evaluator:  The first is unified with 
the SNF conception of the language, while the latter is based on the VNF 
conception.  In order for VNF to also be a complete story, we need to see if 
we can reconcile it with the interactive scope semantics I explained to Hal.
Until I had SNF and VNF clearly separated in my head, I wasn't able to think 
about this well.