The ACD perspective classifies computations as actions, calculations, or data. Applying it reveals hidden decisions, plans, effects, and records so code can be pulled apart deliberately. section 3.3
Use the distinctions as a practical decomposition guide:
- Actions may contain smaller actions, calculations, and data; keep pulling them apart until further decomposition stops helping. section 3.3
- Calculations can combine smaller calculations and data, often passing one calculation’s output into the next. section 3.3
- Data records facts about events and can be composed only from more data, providing stronger behavioral guarantees. section 3.3
Shopping process
A shopping trip contains visible actions, decisions made while choosing what to buy, and records of events. Naming those hidden calculations makes the situation easier to analyze before coding. section 3.3
