[plt-scheme] Re: Casting SPELs in Lisp^H^H^H^H Scheme

From: Carl Eastlund (cce at ccs.neu.edu)
Date: Thu Feb 18 12:55:40 EST 2010

I'm not 100% sure this is what you're running into, but it sounds like it:

If a variable inside a module is not modified by any code in the
module, it gets compiled as an immutable constant.  If you want to be
able to modify it, define (and, perhaps, export) a setter inside the
module.  Then it will be compiled as mutable.

Carl Eastlund

On Thu, Feb 18, 2010 at 12:46 PM, jacmoe <jacmoe at mail.dk> wrote:
> Excellent! :D
> I do get an error, when trying to run this in DrScheme:
> (set! *chain-welded* #t) -> set!: cannot modify a constant: *chain-
> welded*
> I am using Language : module, so it should use full scheme.
> Any hints for a new Schemer? :)

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