Department of Computer Science

Principles of Functional Languages

Fall Semester 2010

Dr. Maury Eggen

Homework Laboratory Assignment One:

This homework assignment is a list management assignment. We shall explore various functions involving lists.

• 1. (count ls) count all items in a (possibly nested) list
• 2. (sum ls) sum all items in a (possibly nested) list of numbers
• 3. (de-nest ls) de-nest takes any list, no matter how deeply nested and makes it into a flat list
• 4. (apnd lsa lsb) apnd hooks two lists together (can not use native append)
• 5. (remove-all item ls) remove-all removes all instances of an item from a (nested) list
• 6. (replace-all old new ls) replace-all replaces all instances of old-item with new-item in a (nested) list
• 7. (add-after a b ls) add-after adds a new item to a (nested) list after every occurrence of a given item
• 8. (add-before b a ls) add-before adds new item to a (nested) list before every occurrence of a given item
• 9. (add-beginning new ls) add-beginning adds a new item to the beginning of a (nested) list
• 10. (add-end new ls) add-end adds a new item to the end of a (nested) list
• 11. (wrap item n) wrap takes a given item and wraps it in parenthesis to any level. For example, (wrap 10 5) would produce (((((10))))).
• 12. (rev ls) rev reverses the items in a list (may not use native reverse)
• 13. (iota n) iota produces a list of the numbers from 0 to (but not including) lits positive integer argument.

Note: Important: you must use the function calls I have indicated to name your functions. Provide a test function that I can run which will 'exercise' all of the functions you submit. I will be grading your homework electronically and will expect these function names. More details in regarding requirements in class.

Homework due date: Friday, September 10, 2010. 26 points.