Simplify by introducing a StaticMember type (#1)

Author: davdroman

AGENTS.md

@@ -0,0 +1,21 @@
+## Agent Guidelines
+
+1. **Test-Driven Mindset**
+   - Treat `swift test` (or equivalent) as part of every instruction unless the user explicitly opts out.
+   - When feasible, add or adjust tests to capture new behavior before changing implementation details.
+   - If tests must be skipped, call it out and explain why.
+
+2. **Iterate on Existing Code**
+   - After implementing a change, re‑evaluate nearby code for redundancy, dead paths, or simplifications that the update enables.
+   - Remove obsolete helpers, APIs, or comments when they no longer add value.
+   - Keep diffs focused: don’t mix unrelated cleanups unless they fall out naturally from the requested work.
+
+3. **README Stewardship**
+   - Ensure `README.md` remains short, accurate, and directly related to the current library surface.
+   - Update usage snippets, API lists, or caveats whenever behavior changes.
+   - Avoid marketing fluff; prioritize concise explanations and practical examples.
+
+4. **Communication Notes**
+   - When parameterizing tests or configurations, prefer explicit argument lists over computed helpers so intent stays readable.
+   - Call out any assumptions, limitations, or skipped steps (e.g., networking constraints, slow tests).
+   - If an instruction conflicts with these guidelines, follow the instruction but highlight the divergence.

README.md

@@ -20,26 +20,42 @@ Add the dependency and product to your `Package.swift`:
 
 ```swift
 import StaticMemberIterable
+import SwiftUI
 
 @StaticMemberIterable
-struct Coffee {
-    let name: String
-    let roastLevel: Int
-
-    static let sunrise = Coffee(name: "sunrise", roastLevel: 2)
-    static let moonlight = Coffee(name: "moonlight", roastLevel: 3)
-    static let stardust = Coffee(name: "stardust", roastLevel: 4)
+enum ColorPalette {
+    static let sunrise: Color = Color(red: 1.00, green: 0.58, blue: 0.22)
+    static let moonlight: Color = Color(red: 0.30, green: 0.32, blue: 0.60)
+    static let stardust: Color = Color(red: 0.68, green: 0.51, blue: 0.78)
 }
 
-Coffee.allStaticMembers       // [sunrise, moonlight, stardust]
-Coffee.allStaticMemberNames   // ["sunrise", "moonlight", "stardust"] as [StaticMemberName]
-Coffee.allNamedStaticMembers  // [(name: "sunrise", value: sunrise), ...] as [(name: StaticMemberName, value: Coffee)]
-
-Coffee.allStaticMemberNames.map(\.title) // ["Sunrise", "Moonlight", "Stardust"]
+ColorPalette.allStaticMembers.map(\.value)   // [.orange, .indigo, .purple] as [Color]
+ColorPalette.allStaticMembers.map(\.title)   // ["Sunrise", "Moonlight", "Stardust"]
+ColorPalette.allStaticMembers.map(\.keyPath) // [\ColorPalette.sunrise, ...] as [KeyPath<ColorPalette.Type, Color>]
 ```
 
 The macro works the same for enums and classes (actors are intentionally unsupported so far).
 
+Each synthesized entry is a `StaticMember<Container, Value>`: an `Identifiable` property wrapper that stores the friendly name, the `KeyPath` to the static property, and the concrete value. This makes it trivial to drive UI:
+
+```swift
+ForEach(ColorPalette.allStaticMembers) { $color in
+    RoundedRectangle(cornerRadius: 12)
+        .fill(color)
+        .overlay(Text($color.title))
+        .tag($color.id)
+}
+```
+
+`StaticMember` exposes four pieces of data:
+
+- `name: String` – keeps the original identifier for the member.
+- `title: String` – human-friendly representation derived from the identifier.
+- `keyPath: KeyPath<Container.Type, Value>` – points back to the static property inside the declaring type.
+- `value`/`wrappedValue: Value` – the actual static instance.
+
+Because it is a property wrapper, you can also project (`$member`) when you use it on your own properties, and `Identifiable` conformance makes it slot neatly into `ForEach`.
+
 ### Access control
 
 Need public-facing lists? Pass the desired access modifier:

Sources/StaticMemberIterable/StaticMember.swift

@@ -0,0 +1,131 @@
+import Foundation
+
+public typealias StaticMemberOf<Container: StaticMemberIterable> = StaticMember<Container, Container.StaticMemberValue>
+
+@propertyWrapper
+public struct StaticMember<Container, Value>: Identifiable {
+	public typealias ID = KeyPath<Container.Type, Value>
+
+	public let keyPath: KeyPath<Container.Type, Value>
+	public let name: String
+
+	private let storage: Value
+
+	public var wrappedValue: Value { storage }
+	public var projectedValue: StaticMember<Container, Value> { self }
+	public var value: Value { storage }
+	public var title: String { name.memberIdentifierTitle() }
+	public var id: ID { keyPath }
+
+	public init(keyPath: KeyPath<Container.Type, Value>, name: String, value: Value) {
+		self.keyPath = keyPath
+		self.name = name
+		self.storage = value
+	}
+
+	public init(projectedValue: StaticMember<Container, Value>) {
+		self.init(keyPath: projectedValue.keyPath, name: projectedValue.name, value: projectedValue.value)
+	}
+
+	public static func ~= (
+		keyPath: ID,
+		staticMember: StaticMember<Container, Value>
+	) -> Bool {
+		staticMember.keyPath == keyPath
+	}
+}
+
+extension StaticMember: @unchecked Sendable where Value: Sendable {}
+
+extension String {
+	fileprivate func memberIdentifierTitle() -> String {
+		let words = memberIdentifierWords()
+		guard !words.isEmpty else { return self }
+		return words
+			.map { word in
+				if word == word.uppercased() {
+					return word
+				}
+
+				guard let first = word.first else { return word }
+				let remainder = word.dropFirst().lowercased()
+				return String(first).uppercased() + remainder
+			}
+			.joined(separator: " ")
+	}
+
+	private func memberIdentifierWords() -> [String] {
+		guard !isEmpty else { return [] }
+
+		var words: [String] = []
+		var current = ""
+		let characters = Array(self)
+
+		func flush() {
+			if !current.isEmpty {
+				words.append(current)
+				current.removeAll(keepingCapacity: true)
+			}
+		}
+
+		for index in characters.indices {
+			let character = characters[index]
+
+			if character.isWordSeparator {
+				flush()
+				continue
+			}
+
+			if index > 0 {
+				let previous = characters[index - 1]
+				let next = index + 1 < characters.count ? characters[index + 1] : nil
+				if character.shouldInsertBreak(before: previous, next: next) {
+					flush()
+				}
+			}
+
+			current.append(character)
+		}
+
+		flush()
+
+		return words
+	}
+}
+
+extension Character {
+	private var isLetter: Bool {
+		unicodeScalars.allSatisfy(CharacterSet.letters.contains)
+	}
+
+	private var isUppercaseLetter: Bool {
+		unicodeScalars.allSatisfy(CharacterSet.uppercaseLetters.contains)
+	}
+
+	private var isLowercaseLetter: Bool {
+		unicodeScalars.allSatisfy(CharacterSet.lowercaseLetters.contains)
+	}
+
+	private var isNumber: Bool {
+		unicodeScalars.allSatisfy(CharacterSet.decimalDigits.contains)
+	}
+
+	fileprivate var isWordSeparator: Bool {
+		self == "_" || self == "-" || self == " "
+	}
+
+	fileprivate func shouldInsertBreak(before previous: Character, next: Character?) -> Bool {
+		switch true {
+		case previous.isLowercaseLetter && isUppercaseLetter:
+			true
+		case previous.isLowercaseLetter && isNumber:
+			true
+		case previous.isNumber && isLetter:
+			true
+		case previous.isUppercaseLetter && isUppercaseLetter && (next?.isLowercaseLetter ?? false):
+			true
+		default:
+			false
+		}
+	}
+}

Sources/StaticMemberIterable/StaticMemberIterable.swift

@@ -1,6 +1,14 @@
+public protocol StaticMemberIterable {
+	associatedtype StaticMemberValue
+}
+
 @attached(
 	member,
-	names: named(allStaticMembers), named(allStaticMemberNames), named(allNamedStaticMembers)
+	names: named(StaticMemberValue), named(allStaticMembers)
+)
+@attached(
+	extension,
+	conformances: StaticMemberIterable
 )
 public macro StaticMemberIterable(
 	_ access: StaticMemberIterableAccess? = nil,