good programming practices rules every programmer should know and follow

Good Programming Practices

rules every programmer should know and follow.

Documentation

• Comment your code such that it is clear what you code does

• You should be able to figure out your code years after it’s written

• A good programmer should be able to figure out what your code does from your comments.

• Scheme comments start with ; ;this is a comment ;this is another comment

Documenting a procedure

Include:1. A description of what the procedure does

2. Type of arguments -> type of return value

3. Constraints that need to be satisfied by arguments (requires clause)

4. Expected state of computation at key states

You should also include notes on what a particular chunk of code does if it may be confusing to a reader.

Documenting a procedure

• Example:

Documenting an ADT

• Whenever you make an ADT, you should include some comments giving an overview of the ADT

• You should describe each sub-unit of the ADT, including the type of the sub-unit

Documenting an ADT

• Example:

Debugging: Using Test Cases

• Whenever you make a procedure, you should write tests for it.– Test the procedure on limits of legal values– Test the procedure with arguments that

span legal values– Include a comment with each test case

indicating what you are testing

Debugging: Useful techniques

• Sometimes, you can use display or print to print out values of your variables at key stages of computation

• Useful for isolating problem spots• In Dr. Scheme, debugger is useful for

checking values of variable in the middle of a computation.