Design Patterns

Apply patterns from two authoritative sources:

• GoF: Design Patterns — Gamma, Helm, Johnson, Vlissides
• PoEAA: Patterns of Enterprise Application Architecture — Martin Fowler

Key principle: patterns describe solutions to recurring problems — use them when the problem recurs, not to demonstrate pattern knowledge. In Go, first-class functions and interfaces make several GoF patterns unnecessary or simpler than in OOP languages.

For encoding pattern invariants into the type system (Value Objects, sum types, smart constructors), apply the type-driven-design skill.

GoF Creational Patterns