mindmap - A Philosophy Of Software Design - POSD

A Philosophy Of Software Design

complexity in software design

• Fighting Against Complexity
  • by eliminating complexity
  • by encapsulating complexity
• The Incremental Nature of Complexity
• Causes Of Complexity
  • dependencies
  • obscurity
• Symptoms of Complexity
  • change amplification
  • cognitive load
  • unknown unknowns

working code is not enough

• Tactical Programming
  • tactical tornado
• Strategic Programming
  • strategic programming investment
    • Investment types
      • reactive
      • proactive
    • How Much to Invest

modules should be deep

• module abstraction
• modular design
  • module interface
  • module implementation
• deep modules
• shallow modules
• classitis

information hiding and information leakage

• information hiding
• information leakage
  • how to prevent information leakage
  • information leakage types
• temporal decomposition

general purpose modules vs special purpose modules

• general purpose module
  • benefits of general-purpose modules
• special purpose module

different layer different abstraction

• pass-through methods
  • why pass-through methods are bad?
• pass-through variables
  • why do pass-through variables add complexity?
• when is interface duplication okay

better together or better apart

• when to bring modules together
• general-purpose and special-purpose code separation
• module division and complexity
• splitting and joining methods
• code repetition

better together or better apart

• module division and complexity
• general-purpose and special-purpose code separation
• when to bring modules together
• splitting and joining methods
• code repetition

Code Comments

• why to write code comments
  • the four excuses not to write comments
    • the myth of good code is self-documented
    • i don’t have time to write comments
    • comments get out of date
    • code comments might be worthless
• how to write better code comments
  • four comment types
    • low-level comments
    • higher-level comments
    • interface comments
    • implementation code comments
  • how to write better comments - pick conventions
  • how to write better comments - don’t repeat the code
• write code comments first

choosing names

• names should be precise
• names should be consistent

modifying existing code

benefits of code consistency

• ensuring consistency

your code can be more obvious

• things that can make the code more obvious
  • consistency
  • comments
  • formatting
• things that can make the code less obvious
  • event driven programming
  • generic containers

better design tips

• design it twice
• why exception adds complexity
• pull complexity downwards