PDA

View Full Version : Problem with DrRacket example



xytron
February 20th, 2012, 06:11 PM
I'm following the tutorial "An Introduction to Racket with Pictures" to become acquainted with Racket.

It's not working. It states that to draw pictures, I must first load some picture functions and to use



#lang slideshow


in the definitions area and click the "run" button, when I do that nothing happens but I don't get any error messages either.

Then I enter the code in the interactions area;



(circle 10)


only to get the following error;

reference to undefined identifier: circle

This happens with anything I try for #lang.

I am using the "Pretty Big" language.

Any ideas?

Thank you.

petru.marginean
July 14th, 2012, 03:02 PM
I have a similar issue: I just downloaded the latest version (v5.2.1), I chose the "Beginning Student" language, and I typed
#lang racket in the top area, and pressed <Run>.
I get the error:

module: this function is not defined.

Any idea what's wrong?
What I could do to investigate this issue?

Here is a screenshot:

http://dl.dropbox.com/u/65655385/drracket-error01.png

Thanks,
PM

dfeltey
July 15th, 2012, 01:04 AM
As far as I can tell the problem is the interaction between choosing the "Beginning Student" language and simultaneously trying to use the #lang directive.

If you choose "Beginning Student" as your language, then that is the language you will be writing in and the #lang directive is unsupported in this dialect of racket.

To use the #lang directive, you need to, from the language menu, tell racket to use the language specified by the #lang directive.

petru.marginean
July 15th, 2012, 11:32 PM
Thanks, using the option "Use the language declared in the source" (Language/Choose Language.." solved the issue.

Many thanks for help,
PM