letrec suggestion

[Guy Steele <gls@think.com>]

   Date: Mon, 8 Jun 92 13:24:28 -0700
   From: William Clinger <will@skinner.cs.uoregon.edu>

   David Carlton writes of letrec:
       In particular, the last bit says that all of the inits have to be
       evaluated before the respective variables are assigned their values.
       I think that this is an unnecessary restriction on implementations -
       implementations should be free to bind the variables to the proper
       values whenever they want to.  (In fact, many implementations don't
       obey the above restriction.)  Was the above section really meant to be
       so restrictive, and, if so, why?

   No, the description of letrec wasn't meant to be so restrictive.
   On the other hand, I think it is easier and better to keep the R4RS
   description of letrec, while changing the implementations, than to
   change the description of letrec to match its common implementation.

   There isn't any great rush to settle this, because no one in his/her
   right mind would write a program that depends on this.

Shall we add a requirement to R5RS to the effect that Scheme
programmers should be in their right minds?  :-)

--Guy