C311 Fall 1996 -- Programming Languages

Scheme Quizette

1. Write the procedure square that takes a number and returns the square of the number.

   > (square 1)
   1
   > (square 9)
   81
        
   
   
   
   
   
   
   
   
   

2. Write the procedure member? that takes an atom a and a list ls and returns #t if a is in ls and #f otherwise.

   > (member? (quote c) (quote (s c h e m e)))
   #t     
   > (member? (quote basic) (quote (s c h e m e)))
   #f     
   
   
   
   
   
   
   
   
   
   
   
   

3. Write the procedure duplicate that takes a number n and an atom a and returns a list containing only n occurrences of a.

   > (duplicate 3 'foo)
   (foo foo foo)
   > (duplicate 0 'foo)
   ()