I'm a beginner learning Scheme. I tried to follow the quick introduction to get familiar with the syntax, but stuck in step 3. When I type (circle 10), it gives me "circle: undefined; cannot reference an identifier before its definition" Do I miss some library or I have to define circle first?
1 Answers
2
votes
You are using the racket language, but Racket is actually an ecosystem of many programming languages. The Quick tutorial uses the slideshow language, a variant of Racket designed for creating pictorial programs and slideshows. As mentioned in section 2 of the tutorial, change the first line of your program to this:
#lang slideshow
…click Run, and circle should now be defined.