Add PreferenceKeys and update HostPreferencesKey (#35)

* Update gitignore file

* Add PreferenceKeys and update Preference folder structure

* Implement HostPreferencesKey reduce

* Add HostPreferencesKeyTests test case

Author: Kyle-Ye

.gitignore

@@ -10,4 +10,5 @@ Example/.swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata
 /.build-*
 /Benchmarks/.build
 /Example/.build
-Example/Package.resolved
+Example/Package.resolved
+TODO.md

Sources/OpenSwiftUI/DataAndStorage/Preferences/Internal/AnyPreferenceKey.swift renamed to Sources/OpenSwiftUI/DataAndStorage/Preferences/AnyPreferenceKey.swift

@@ -4,17 +4,15 @@
 //
 //  Created by Kyle on 2023/1/6.
 //  Lastest Version: iOS 15.5
-//  Status: WIP
+//  Status: Complete
 //  ID: 7429200566949B8FB892A77E01A988C8
 
 struct HostPreferencesKey: PreferenceKey {
-    static var defaultValue: PreferenceList {
-        PreferenceList()
-    }
+    private static var nodeId: UInt32 = .zero
 
-    static func reduce(value: inout PreferenceList, nextValue: () -> PreferenceList) {
-        // TODO:
+    @inline(__always)
+    static func makeNodeID() -> UInt32 {
+        defer { nodeId &+= 1 }
+        return nodeId
     }
-    
-    private static var nodeId: UInt32 = .zero
 }

Sources/OpenSwiftUI/DataAndStorage/Preferences/Internal/HostPreferenceKey.swift renamed to Sources/OpenSwiftUI/DataAndStorage/Preferences/HostPreferenceKey.swift

@@ -0,0 +1,73 @@
+//
+//  PreferenceKeys.swift
+//  OpenSwiftUI
+//
+//  Created by Kyle on 2024/2/2.
+//  Lastest Version: iOS 15.5
+//  Status: Complete
+
+struct PreferenceKeys {
+    private var keys: [AnyPreferenceKey.Type]
+    
+    init() {
+        self.keys = []
+    }
+}
+
+extension PreferenceKeys: RandomAccessCollection, MutableCollection {
+    var startIndex: Int { keys.startIndex }
+    var endIndex: Int { keys.endIndex }
+    
+    mutating func add<Key: PreferenceKey>(_: Key.Type) {
+        keys.append(_AnyPreferenceKey<Key>.self)
+    }
+    
+    mutating func add(_ key: AnyPreferenceKey.Type) {
+        keys.append(key)
+    }
+    
+    func contains<Key: PreferenceKey>(_: Key.Type) -> Bool {
+        contains(_AnyPreferenceKey<Key>.self)
+    }
+    
+    func contains(_ key: AnyPreferenceKey.Type) -> Bool {
+        keys.contains { $0 == key }
+    }
+    
+    mutating func remove<Key: PreferenceKey>(_: Key.Type) {
+        remove(_AnyPreferenceKey<Key>.self)
+    }
+    
+    mutating func remove(_ key: AnyPreferenceKey.Type) {
+        for index in keys.indices {
+            if keys[index] == key {
+                keys.remove(at: index)
+                return
+            }
+        }
+    }
+    
+    var isEmpty: Bool { keys.isEmpty }
+
+    subscript(position: Int) -> AnyPreferenceKey.Type {
+        get { keys[position] }
+        set { keys[position] = newValue }
+    }
+}
+
+extension PreferenceKeys: Equatable {
+    static func == (lhs: PreferenceKeys, rhs: PreferenceKeys) -> Bool {
+        guard lhs.keys.count == rhs.keys.count else {
+            return false
+        }
+        guard !lhs.keys.isEmpty else {
+            return true
+        }
+        for index in lhs.indices {
+            guard lhs[index] == rhs[index] else {
+                return false
+            }
+        }
+        return true
+    }
+}

Sources/OpenSwiftUI/DataAndStorage/Preferences/Internal/HostPreferencesKey.swift renamed to Sources/OpenSwiftUI/DataAndStorage/Preferences/HostPreferencesKey.swift

@@ -8,7 +8,7 @@
 //  ID: C1C63C2F6F2B9F3EB30DD747F0605FBD
 
 struct PreferenceList: CustomStringConvertible {
-    private var first: PreferenceNode?
+    fileprivate var first: PreferenceNode?
 
     subscript<Key: PreferenceKey>(_ keyType: Key.Type) -> Value<Key.Value> {
         get {
@@ -174,3 +174,34 @@ private class _PreferenceNode<Key: PreferenceKey>: PreferenceNode {
         "\(Key.self) = \(value)"
     }
 }
+
+extension HostPreferencesKey {
+    static var defaultValue: PreferenceList {
+        PreferenceList()
+    }
+    
+    static func reduce(value: inout PreferenceList, nextValue: () -> PreferenceList) {
+        let newValue = nextValue()
+        guard let newFirst = newValue.first else {
+            return
+        }
+        guard let first = value.first else {
+            value.first = newFirst
+            return
+        }
+        value.first = nil
+        first.forEach { node in
+            if let mergedNode = node.combine(from: newFirst, next: value.first) {
+                value.first = mergedNode
+            } else {
+                value.first = node.copy(next: value.first)
+            }
+        }
+        newFirst.forEach { node in
+            guard node.find(from: first) == nil else {
+                return
+            }
+            value.first = node.copy(next: value.first)
+        }
+    }
+}

Sources/OpenSwiftUI/DataAndStorage/Preferences/Internal/PreferenceKeyVisitor.swift renamed to Sources/OpenSwiftUI/DataAndStorage/Preferences/PreferenceKeyVisitor.swift

@@ -4,7 +4,7 @@
 //
 //  Created by Kyle on 2023/9/24.
 //  Lastest Version: iOS 15.5
-//  Status: WIP
+//  Status: Complete
 
 extension View {
     /// Sets a value for the given preference.

Sources/OpenSwiftUI/DataAndStorage/Preferences/PreferenceKeys.swift

@@ -0,0 +1,113 @@
+//
+//  HostPreferencesKeyTests.swift
+//
+//
+//  Created by Kyle on 2024/2/4.
+//
+
+@testable import OpenSwiftUI
+import Testing
+
+struct HostPreferencesKeyTests {
+    struct IntKey: PreferenceKey {
+        static var defaultValue: Int { 0 }
+        
+        static func reduce(value: inout Int, nextValue: () -> Int) {
+            value += nextValue()
+        }
+    }
+    
+    struct DoubleKey: PreferenceKey {
+        static var defaultValue: Double { 0.0 }
+        
+        static func reduce(value: inout Double, nextValue: () -> Double) {
+            value += nextValue()
+        }
+    }
+    
+    struct EnumKey: PreferenceKey {
+        static func reduce(value: inout Value, nextValue: () -> Value) {
+            let newValue = (value.rawValue + nextValue().rawValue) % Value.allCases.count
+            value = .init(rawValue: newValue)!
+        }
+        
+        enum Value: Int, CaseIterable { case a, b, c, d }
+        static var defaultValue: Value { .a }
+    }
+    
+    struct IntKey2: PreferenceKey {
+        static var defaultValue: Int { 0 }
+        
+        static func reduce(value: inout Int, nextValue: () -> Int) {
+            value *= nextValue()
+        }
+    }
+    
+    struct DoubleKey2: PreferenceKey {
+        static var defaultValue: Double { 0.0 }
+        
+        static func reduce(value: inout Double, nextValue: () -> Double) {
+            value *= nextValue()
+        }
+    }
+    
+    @Test
+    func nodeID() {
+        let id0 = HostPreferencesKey.makeNodeID()
+        let id1 = HostPreferencesKey.makeNodeID()
+        let id2 = HostPreferencesKey.makeNodeID()
+        #expect(id1 == (id0 + 1))
+        #expect(id2 == (id1 + 1))
+    }
+    
+    @Test(arguments: [
+        ([1, 2, 3, 4], [3, 12], [1.0, 2.0, 3.0, 4.0], [3.0, 12.0], [EnumKey.Value.a, .b, .c, .d], [EnumKey.Value.b, .a]),
+        ([0, 4, 5, 6], [4, 30], [0.0, 1.0, 2.0, 3.0], [1.0, 6.0], [EnumKey.Value.a, .c, .d, .b], [EnumKey.Value.c, .d]),
+        ([1, 7, 0, 5], [8, 0], [2.0, 1.5, 0.0, 5.0], [3.5, 0.0], [EnumKey.Value.c, .a, .b, .d], [EnumKey.Value.c, .b]),
+    ])
+    func reduce(
+        intValues: [Int], expectedIntValues: [Int],
+        doubleValues: [Double], expectedDoubleValues: [Double],
+        enumValues: [EnumKey.Value], expectedEnumValues: [EnumKey.Value]
+    ) {
+        var value = HostPreferencesKey.defaultValue
+        value[IntKey.self] = .init(value: intValues[0], seed: .init(value: 1))
+        value[EnumKey.self] = .init(value: enumValues[0], seed: .init(value: 2))
+        value[DoubleKey.self] = .init(value: doubleValues[0], seed: .init(value: 3))
+        #expect(value.description == """
+        372598479: [DoubleKey = \(doubleValues[0]), EnumKey = \(enumValues[0]), IntKey = \(intValues[0])]
+        """)
+        HostPreferencesKey.reduce(value: &value) {
+            var nextValue = HostPreferencesKey.defaultValue
+            nextValue[IntKey2.self] = .init(value: intValues[2], seed: .init(value: 4))
+            nextValue[EnumKey.self] = .init(value: enumValues[1], seed: .init(value: 5))
+            nextValue[DoubleKey2.self] = .init(value: doubleValues[2], seed: .init(value: 6))
+            #expect(nextValue.description == """
+            3126765658: [DoubleKey2 = \(doubleValues[2]), EnumKey = \(enumValues[1]), IntKey2 = \(intValues[2])]
+            """)
+            return nextValue
+        }
+        #expect(value.description == """
+        1584719037: [IntKey2 = \(intValues[2]), DoubleKey2 = \(doubleValues[2]), IntKey = \(intValues[0]), EnumKey = \(expectedEnumValues[0]), DoubleKey = \(doubleValues[0])]
+        """)
+        HostPreferencesKey.reduce(value: &value) {
+            var nextValue = HostPreferencesKey.defaultValue
+            nextValue[DoubleKey.self] = .init(value: doubleValues[1], seed: .init(value: 7))
+            nextValue[EnumKey.self] = .init(value: enumValues[2], seed: .init(value: 8))
+            nextValue[IntKey.self] = .init(value: intValues[1], seed: .init(value: 9))
+            #expect(nextValue.description == """
+            1190677337: [IntKey = \(intValues[1]), EnumKey = \(enumValues[2]), DoubleKey = \(doubleValues[1])]
+            """)
+            nextValue[DoubleKey2.self] = .init(value: doubleValues[3], seed: .init(value: 7))
+            nextValue[EnumKey.self] = .init(value: enumValues[3], seed: .init(value: 8))
+            nextValue[IntKey2.self] = .init(value: intValues[3], seed: .init(value: 9))
+            #expect(nextValue.description == """
+            1148928659: [IntKey2 = \(intValues[3]), EnumKey = \(enumValues[3]), DoubleKey = \(doubleValues[1]), IntKey = \(intValues[1]), DoubleKey2 = \(doubleValues[3])]
+            """)
+            return nextValue
+        }
+        #expect(value.description == """
+        2384310348: [DoubleKey = \(expectedDoubleValues[0]), EnumKey = \(expectedEnumValues[1]), IntKey = \(expectedIntValues[0]), DoubleKey2 = \(expectedDoubleValues[1]), IntKey2 = \(expectedIntValues[1])]
+        """)
+    }
+}

Sources/OpenSwiftUI/DataAndStorage/Preferences/Internal/PreferenceList.swift renamed to Sources/OpenSwiftUI/DataAndStorage/Preferences/PreferenceList.swift

@@ -0,0 +1,69 @@
+//
+//  PreferenceListTests.swift
+//
+//
+//  Created by Kyle on 2024/2/4.
+//
+
+@testable import OpenSwiftUI
+import Testing
+
+struct PreferenceListTests {
+    struct IntKey: PreferenceKey {
+        static var defaultValue: Int { 0 }
+        
+        static func reduce(value: inout Int, nextValue: () -> Int) {
+            value += nextValue()
+        }
+    }
+    
+    struct DoubleKey: PreferenceKey {
+        static var defaultValue: Double { 0.0 }
+        
+        static func reduce(value: inout Double, nextValue: () -> Double) {
+            value += nextValue()
+        }
+    }
+    
+    struct EnumKey: PreferenceKey {
+        static func reduce(value: inout Value, nextValue: () -> Value) {
+            value = nextValue()
+        }
+        
+        enum Value { case a, b }
+        static var defaultValue: Value { .a }
+    }
+    
+    
+    @Test("Test description and subscript with zero seed")
+    func subscriptAndDescriptionWithZeroSeed() {
+        var list = PreferenceList()
+        #expect(list.description == "empty: []")
+        list[IntKey.self] = PreferenceList.Value(value: 1, seed: .zero)
+        #expect(list.description == "empty: [IntKey = 1]")
+        list[DoubleKey.self] = PreferenceList.Value(value: 1.0, seed: .zero)
+        #expect(list.description == "empty: [DoubleKey = 1.0, IntKey = 1]")
+        list[IntKey.self] = PreferenceList.Value(value: 2, seed: .zero)
+        #expect(list.description == "empty: [IntKey = 2, DoubleKey = 1.0]")
+        list[DoubleKey.self] = PreferenceList.Value(value: 1.0, seed: .zero)
+        #expect(list.description == "empty: [DoubleKey = 1.0, IntKey = 2]")
+        list[EnumKey.self] = PreferenceList.Value(value: .a, seed: .zero)
+        #expect(list.description == "empty: [EnumKey = a, DoubleKey = 1.0, IntKey = 2]")
+    }
+    
+    @Test("Test description and subscript with seed")
+    func subscriptAndDescriptionWithSeed() {
+        var list = PreferenceList()
+        #expect(list.description == "empty: []")
+        list[IntKey.self] = PreferenceList.Value(value: 1, seed: .init(value: 1))
+        #expect(list.description == "1: [IntKey = 1]")
+        list[DoubleKey.self] = PreferenceList.Value(value: 1.0, seed: .init(value: 2))
+        #expect(list.description == "547159728: [DoubleKey = 1.0, IntKey = 1]")
+        list[IntKey.self] = PreferenceList.Value(value: 2, seed: .init(value: 3))
+        #expect(list.description == "3634229150: [IntKey = 2, DoubleKey = 1.0]")
+        list[DoubleKey.self] = PreferenceList.Value(value: 1.0, seed: .init(value: 4))
+        #expect(list.description == "1218402493: [DoubleKey = 1.0, IntKey = 2]")
+        list[EnumKey.self] = PreferenceList.Value(value: .a, seed: .init(value: 5))
+        #expect(list.description == "1817264013: [EnumKey = a, DoubleKey = 1.0, IntKey = 2]")
+    }
+}