CSC103 How Computers Work

Notes 10

Programming (continued)

1. Scratch

2. Scratch Programming Concepts
   • Sequencing: a sequence of steps
     • something like a recipe
     • one processor needs a single sequence
     • parallel programming is like several cooks preparing subparts of meal at once
   • Iteration: repeating a series of actions
   • Variables: named storage whose contents can change/vary
   • Many other concepts not illustrated
   • Conditional execution:
     • if this happens, then do this, otherwise do that.
   • Named Procedures
     • Encapsulate code, package it, give it a name
     • Invoke by "calling" its name
3. Could write fairly sophisticated games
4. Illustrate one: pacman
5. Review of translation process:
• source code → byte code → machine language → electric current → results

6. Web Programming

7. JavaScript: Client-side web programming
   • Example: TickerForm.html
   • Example: Image Rollovers, e.g., here.
   • Example: Browser detection.

8. php: Server-side web programming
• Example: CS courses

9. Genetic Programming

10. Genetic Programming in LISP
11. Idea: generate many "random" programs for a task.
    • Test them on task.
    • Discard the worst performers.
    • "Mate" the best programs to replace them with offspring programs.
    • Repeat.

12. Running blackjack code:

    [1]> (load "blackjack.fas")
    ;; Loading file blackjack.fas ...
    ;; Loaded file blackjack.fas
    T
    [2]> (load "bgen.fas")
    ;; Loading file bgen.fas ...
    ;; Loaded file bgen.fas
    T
    [3]> (gen-with-mating 10 5 1 4)
    
      

13. Review of Take-Home
14. Review of Paper