Swift API Design Guidelines

Follow Apple's Swift API Design Guidelines so code feels consistent with the Swift ecosystem. For full detail and examples, see reference.md.

When to Apply

Writing or refactoring Swift types, functions, methods, properties, or parameters
Reviewing Swift code for API clarity and naming
User asks for Swift style, naming conventions, or API design

Clarity at the point of use is the top goal. Design so call sites read clearly, not just the declaration.
Clarity over brevity. Avoid minimizing character count for its own sake.
Document every declaration with a doc comment. Use Swift's Markdown dialect. Start with a one-line summary (sentence fragment, period). If the API is hard to describe simply, reconsider the design.
Document non-O(1) computed properties so callers don't assume cheap access.