[plt-scheme] Re: DrScheme: Reference to undefined identifier: require

From: Daniel (phelps.da at gmail.com)
Date: Tue Aug 4 16:48:56 EDT 2009

  Your answer was right on, and I was able to figure out the details.
Life seems a bit easier when using module, require and provide.  I
picked R5RS when I began, because DrScheme says it's "no frills", and
I'm a no frills kind of guy.  Following your recommendation broke a
couple things, but nothing that could not be fixed in 5 minutes.

This is how things ended up:

In ch-2.scm:
(module ch-2 mzscheme
  ; - A collection of super-clever solutions to problems in my
(provide $FUNCTION_NAMES))

In ch-2-tests.scm:
(module ch-2-tests mzscheme
  (require "ch-2.scm")
  (require "dp-test-framework.scm")
  ;  - The test suite for my impressive solutions.

In dp-test-framework.scm:
(module dp-test-framework mzscheme
  ;a pretty cute way to run tests and aggregate the results

Based on what you see above, do I understand module, require and
provide?  Is this a good way to work with Scheme?  Do you have any
pointers for a newbie?  I look forward to hearing your response.
Thanks for your help so far.


On Aug 3, 7:58 pm, Zane Shelby <zaneshe... at gmail.com> wrote:
> Hey Daniel!
> The problem is 'require' isn't part of the R5RS language, so when you
> try to use it in that language you're going to get an error. You could
> use load, but that has slightly different behavior.
> Is there particular reason why you'd like to use r5rs? If not, I'd
> recommend you use PLT Scheme by selecting 'module' from the pulldown
> and putting '#lang scheme' at the top of your file.
> Hope that helps,
> Zane
> On Mon, Aug 3, 2009 at 12:09 PM, Daniel<phelps... at gmail.com> wrote:
> > Hello Everybody:
> >    I am new to Scheme, so please be patient with me.  I have 2 files:
> > ch2.scm and schemeTests.scm.  I would like to include schemeTests.scm
> > in the ch2.scm file.
> > According to the documentation, the include procedure "inlines the
> > syntax in the file designated by path-spec in place of the include
> > expression."  http://docs.plt-scheme.org/reference/include.html This
> > behavior is what I need.  However, I am having some trouble.
> > Hopefully, this short interactive session can tell you something.
> > Welcome to DrScheme, version 4.2.1 [3m].
> > Language: R5RS; memory limit: 128 megabytes.
> >> (require scheme/include)
> > . . reference to undefined identifier: require
> >> (include "schemeTests.scm")
> > . . reference to undefined identifier: include
> >> #lang scheme
> > . . reference to undefined identifier: module
> > If I place a call to (require scheme/include) in my source file, I
> > receive the same error.  However, if I change the language from R5RS
> > to advanced student custom, I get no complaints about 'require', but
> > it breaks some of my previously existing code.  What am I doing
> > wrong?  Your help and consideration is appreciated.
> > Sincerely,
> > Daniel
> > _________________________________________________
> >  For list-related administrative tasks:
> >  http://list.cs.brown.edu/mailman/listinfo/plt-scheme
> _________________________________________________
>   For list-related administrative tasks:
>  http://list.cs.brown.edu/mailman/listinfo/plt-scheme

Posted on the users mailing list.