[plt-scheme] Re: servlets and stuff

From: Matthias Felleisen (matthias at ccs.neu.edu)
Date: Thu Oct 13 20:42:50 EDT 2005

On Oct 13, 2005, at 8:06 PM, Paul A. Steckler wrote:

>>> Language levels are modes, and modes should be
>>> deprecated.  But if you've gotta have 'em, make
>>> 'em obvious.
>> In what sense are they modes?
> They're modes in that they affect the entire operation
> of the program.  Think of language editing modes in
> emacs; language levels have even more pervasive effects.
> If I edit a Scheme program in fundamental mode, I get
> funny indenting behavior.  That why it's useful that
> emacs displays its editing modes in the status bar.

Semantically -- and soon in DrScheme -- a language level is a
module with a non-mzscheme language. In that case, the behavior
is uniform, except that the require specs assign new/improved
meaning to certain expressions. That'll be true at the Scheme
level. I don't think this is a mode, unless all meaning
changing import statements in ML are modes, too.

-- Matthias

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