Semester Review Topics List

We have learned about randomness, writing consistent signatures for big-bang, writing high quality tests, and how to limit numerical values.

Recent major topics

  • Randomness

    • Work with a non-random function first.
      • Non-random function has more parameters than random version.
      • Testable.
    • Random function
      • Calls non-random function with random input.
      • Not usually tested.

  • Signatures / Big-Bang

    • Information flow must be consistent
    • Write signatures for everything
    • Test everything individually
    • Use check-with to catch signature errors. (See below.)

  • Testing

    • Write two tests for each function.
    • Especially when you do not know how to make it work! (Fight instinct to just hack.)
    • Use different numbers for each argument in a test. (Why is this important?)

Minor Topics

Still important enough to mention.

  • Numerical functions that limit or convert values:

    • min, max to limit values
    • real->int
    • round, ceiling, floor

  • People coordinates

    • Changing to and from

  • String functions.

    • substring: both the two and three argument versions.

Details on check-with

Example in big-bang is: (check-with posn?). More in click-circle writeup. The check-with command is first introduced in Chapter 8, book page 137, PDF page 148.