Re: [MIT-Scheme-users] let-fluid

[Taylor R Campbell]

   Date: Tue, 25 Aug 2015 10:46:16 +0300
   From: David Gray <address@hidden>

   I also thought to use the latest version of scmutils20150730 as Frederico.
   I managed to compile the latest git version and to compile the latest
   version of scmutils but ran into problems with fluid-let using the following 
code:

   (fluid-let ((flonum-unparser-cutoff '(relative 5)))
     (number->string (* 4 (atan 1 1))))

   giving:
   The object (relative 5), passed as an argument to fluid, is not a fluid.

This is another fluid compatibility issue -- in Git, FLUID-LET as
temporary shallow-binding of global variables has largely been
replaced by local deep-binding of objects called fluids, but nobody
has made an effort to maintain any semblance of compatibility (yet).

So you have to write:

(let-fluid flonum-unparser-cutoff '(relative 5)
  (lambda ()
    ...))

This should be sorted out before the next release of MIT Scheme, but
Gerry likes to stay on the bleeding edge with scmutils.