[r6rs-discuss] Problems with EVAL

From: AndrevanTonder <andre>
Date: Wed, 12 Sep 2007 21:23:46 -0400 (EDT)

A couple of problems with EVAL. First, the easy one: I think this text has
problem:

   "environment-specifier must be a library specifier, which can be created
    using the environment procedure described below"

Specifically, there is no mention in the description of ENVIRONMENT of the term
"library specifier". Instead, it is stated that ENVIRONMENT returns an
"environment" and I do not understand why this apparently doubly redundant
triple indirection of terms is used instead of of just specifying:

    (eval expression environment)

and simply saying that an environment may be created by using ENVIRONMENT.

Then, the more difficult problem. The arguments of ENVIRONMENT are generally
not known until runtime, so I do not understand how a compiled program
containing ENVIRONMENT can find the necessary libraries unless one /requires/
that ENVIRONMENT may only have as arguments libraries that are present
in the <import clause> of the toplevel program or library containing the
use of ENVIRONMENT. Yet this is not mentioned. Am I missing something?

Andre
Received on Wed Sep 12 2007 - 21:23:46 UTC