'error' procedure is undefined in plt-r5rs

Question

I have this file named myprog.scm:

(error "Not found!")

Running the program using plt-r5rs myprog.scm gives an error:

error: undefined;
 cannot reference undefined identifier
  context...:
   /usr/share/racket/pkgs/r5rs-lib/r5rs/run.rkt: [running body]

Apparently, plt-r5rs does not define the error procedure.

• Why did the authors of plt-r5rs not define the error procedure?
• How can I define or import an error procedure so that my program can run? Perhaps there's a way to import SRFI-23 Error reporting mechanism?

Answer 1

Why did the authors of plt-r5rs not define the error procedure?

It appears that The Revised⁵ Report on the Algorithmic Language Scheme does not define a procedure named error. The initial environment created by plt-r5rs contains only the values and syntactic forms defined in the report (except for a handful of implementation-specific forms listed in the docs, like #%require, which are not legal identifiers according to R⁵RS).

How can I define or import an error procedure so that my program can run? Perhaps there's a way to import SRFI-23 Error reporting mechanism?

As you probably know, R⁵RS also does not define a module system, so there is no portable way to import anything. For plt-r5rs specifically, this version of your program works:

(#%require srfi/23)
(error "Not found!")

Of course, if you are relying on details of plt-r5rs already, I would suggest just using Racket, or at least R⁶RS.