Swift API Design Guidelines

Naming and interface-design rules from Apple's official API Design Guidelines. The prime directive: clarity at the point of use is the goal, and clarity is more important than brevity. A declaration is written once and read at every call site — optimize the call site.

• Enforcement: most of this is judgment a linter can't check; swiftlint catches the mechanical subset (identifier casing, redundant names). See the swiftlint skill.
• Language idioms (optionals, generics, protocol design mechanics): swift-patterns.
• KMP boundary: the Swift signatures a shared Kotlin module exposes are named by Kotlin/SKIE, not by you — audit them against these rules and rename with @ObjCName / SKIE where the generated names read poorly. See kmp-ios-integration.

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