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Scheme errors?



    Date: Tue, 11 Nov 86 01:22 EST
    From: Ramin Zabih <RDZ at AI.AI.MIT.EDU>

    Have I missed something in my reading of the Scheme report, or is there
    in fact no defined way for a program to signal an error?

You didn't miss anything.  However, no such mechanism is needed, because
as long as you avoid defining the variable "error", it should simply
work to say (error ...).  The effect will be a reference to an unbound
variable, and if the debugging system is halfway decent you'll be able
to see the arguments.

Seriously though, I think most implementations have an "error" procedure
(or special form) which is compatible with S&ICP (and not with CL).  But
it might be nice if we in fact standardized on this.  Ideally of course
it would be part of a real error (condition) system, though, and it's
possible that that would in turn depend on having fluid variables... I
wouldn't hold my breath...

Jonathan