Index

Day 4 - Formatting

Vertical formatting

• File size = class size
• Small files are usually easier to understand than large files
• Newspaper metaphor:
  You read the newspaper vertically. At the top you expect a headline that tell you what the story is about and allows you to decide whether it is something you want to read. The topmost parts should provide high-level concepts and algorithms. Details should increase as we move downward
• Each group of lines represents a complete thought. Those thoughts should be separated from each other with blank lines
• Lines of code that are tightly related should appear vertically dense, without having to move my head or eyes much
• Concepts that are closely related should be kept vertically close to each other.
  Closely related concepts should not be separated into different files unless you have a very good reason. Indeed, this is one of the reasons that protected variables should be avoided (use get/set instead!)
• Variable declarations should be as close to their usage as possible. Because our functions are very short, local variables should appear at the top of each function
• Instance variables should be declared at the top of the class (or at the bottom: C++)
• Dependent functions: if one function calls another, they should be vertically close, and the caller should be above the callee, if at all possible. This gives the program a natural flow
• Conceptual affinity: certain bits of code want to be near other bits. They have a certain conceptual affinity. The stronger that affinity, the less vertical distance there should be between them