Interface Design

Master Go's approach to interfaces: implicit satisfaction, consumer-driven design, and composition patterns.

Route by Concern

• Accept/return patterns → see design/

  • Accept interfaces, return structs principle
  • When to deviate from the rule

• Interface pollution → see pollution/

  • Detecting unnecessary abstractions
  • Premature interface creation

• Embedding patterns → see embedding/

  • Interface composition techniques
  • Method set expansion

Quick Check

• Interface defined by consumer, not producer
• Keep interfaces small (<5 methods)
• Return concrete types from functions
• No interface{} unless truly necessary