[Feature] Update ViewList

.swiftformat

@@ -5,13 +5,19 @@
 --asynccapturing 
 --beforemarks 
 --binarygrouping 4,8
+--callsiteparen default
 --categorymark "MARK: %c"
 --classthreshold 0
 --closingparen balanced
 --closurevoid remove
 --commas always
+--complexattrs preserve
+--computedvarattrs preserve
+--condassignment after-property
 --conflictmarkers reject
+--dateformat system
 --decimalgrouping 3,6
+--doccomments before-declarations
 --elseposition same-line
 --emptybraces no-space
 --enumnamespaces always
@@ -30,46 +36,51 @@
 --header ignore
 --hexgrouping 4,8
 --hexliteralcase uppercase
---ifdef no-indent
+--ifdef indent
 --importgrouping alpha
 --indent 4
 --indentcase false
 --indentstrings false
+--initcodernil false
 --lifecycle 
 --lineaftermarks true
 --linebreaks lf
 --markcategories true
 --markextensions always
 --marktypes always
 --maxwidth none
---modifierorder 
+--modifierorder nonisolated,public
 --nevertrailing 
+--nilinit remove
+--noncomplexattrs 
 --nospaceoperators 
 --nowrapoperators 
 --octalgrouping 4,8
 --onelineforeach ignore
 --operatorfunc spaced
+--organizationmode visibility
 --organizetypes actor,class,enum,struct
 --patternlet hoist
 --ranges spaced
---redundanttype inferred
+--redundanttype infer-locals-only
 --self remove
 --selfrequired 
 --semicolons inline
---shortoptionals always
+--shortoptionals except-properties
 --smarttabs enabled
---someany false
+--someany true
+--storedvarattrs preserve
 --stripunusedargs always
 --structthreshold 0
---swiftversion 5.10
 --tabwidth unspecified
 --throwcapturing 
+--timezone system
 --trailingclosures 
---trimwhitespace nonblank-lines
+--trimwhitespace always
 --typeattributes preserve
 --typeblanklines remove
+--typedelimiter space-after
 --typemark "MARK: - %t"
---varattributes preserve
 --voidtype void
 --wraparguments preserve
 --wrapcollections preserve
@@ -82,5 +93,4 @@
 --wraptypealiases preserve
 --xcodeindentation disabled
 --yodaswap always
---disable blankLineAfterImports,wrapMultilineStatementBraces
---enable acronyms,blankLinesBetweenImports
+--disable unusedArguments

Sources/OpenSwiftUICore/Data/Transaction/TransitionTraitKey.swift

@@ -0,0 +1,22 @@
+//
+//  TransitionTraitKey.swift
+//  OpenSwiftUICore
+//
+//  Audited for iOS 18.0
+//  Status: WIP
+
+@usableFromInline
+struct CanTransitionTraitKey: _ViewTraitKey {
+    @inlinable
+    static var defaultValue: Bool { false }
+}
+
+@available(*, unavailable)
+extension CanTransitionTraitKey: Sendable {}
+
+extension ViewTraitCollection {
+    package var canTransition: Bool {
+        get { self[CanTransitionTraitKey.self] }
+        set { self[CanTransitionTraitKey.self] = newValue }
+    }
+}

Sources/OpenSwiftUICore/Graph/GraphInputs.swift

@@ -199,6 +199,13 @@ public struct _GraphInputs {
     package struct Phase: Equatable {
         var value: UInt32
 
+        @inline(__always)
+        static var isBeingRemovedBitCount: Int { 1 }
+        @inline(__always)
+        static var isBeingRemovedMask: UInt32 { (1 << isBeingRemovedBitCount) - 1}
+        @inline(__always)
+        static var resetSeedMask: UInt32 { ~isBeingRemovedMask }
+
         @inlinable
         package init(value: UInt32) {
             self.value = value
@@ -211,19 +218,17 @@ public struct _GraphInputs {
 
         @inlinable
         package var resetSeed: UInt32 {
-            get { value >> 1 }
-            set { value = (newValue << 1) | (value & 1) }
+            get { value >> Self.isBeingRemovedBitCount }
+            set { value = (newValue << Self.isBeingRemovedBitCount) | (value & Self.isBeingRemovedMask) }
         }
 
         package var isBeingRemoved: Bool {
-            get { value & 1 != 0 }
-            set { value = (newValue ? 1 : 0) | (value & 0xFFFF_FFFE) }
+            get { (value & Self.isBeingRemovedMask) != 0 }
+            set { value = (newValue ? 1 : 0) | (value & Self.resetSeedMask) }
         }
 
         @inlinable
-        package var isInserted: Bool {
-            value & 1 == 0
-        }
+        package var isInserted: Bool { !isBeingRemoved }
 
         @inlinable
         package mutating func merge(_ other: _GraphInputs.Phase) {

Sources/OpenSwiftUICore/Graph/GraphReuse.swift

@@ -12,7 +12,7 @@ package import OpenGraphShims
 package typealias Subgraph = OGSubgraph
 package typealias Graph = OGGraph
 
-package final class IndirectAttributeMap {
+public final class IndirectAttributeMap {
     #if canImport(Darwin)
     package final let subgraph: Subgraph
     package final var map: [AnyAttribute: AnyAttribute]

Sources/OpenSwiftUICore/Graph/ReuseTrace.swift

@@ -34,7 +34,23 @@ package struct ReuseTrace {
     package static func traceReuseViewInputsDifferentFailure() {
         traceReuseFailure("reuse_inputsDifferent")
     }
-
+
+    @inline(__always)
+    package static func traceReuseUnaryElementExpectedFailure(_ elementType: any Any.Type) {
+        traceReuseFailure("reuse_unaryElement")
+    }
+
+    @inline(__always)
+    package static func traceReuseInvalidSubgraphFailure(_ typeFoundInvalid: any Any.Type) {
+        // FIXME: ReuseTraceInternal.InvalidSubgraphFailure
+        traceReuseFailure("reuse_invalidSubgraph")
+    }
+
+    @inline(__always)
+    package static func traceReuseBodyMismatchedFailure() {
+        traceReuseFailure("reuse_bodyMismatched")
+    }
+
     // TODO
 
     final package class Recorder {

Sources/OpenSwiftUICore/Modifier/ViewModifier/CustomViewModifier.swift

@@ -139,3 +139,56 @@ extension _ViewModifier_Content {
         }
     }
 }
+
+// MARK: - BodyInput
+
+// FIXME
+private struct BodyInput<Input> {}
+
+private enum BodyInputElement: GraphReusable, Equatable {
+    typealias MakeViewBody = (_Graph, _ViewInputs) -> _ViewOutputs
+    typealias MakeViewListBody = (_Graph, _ViewListInputs) -> _ViewListOutputs
+
+    case view(MakeViewBody)
+    case list(MakeViewListBody)
+
+    static func == (lhs: BodyInputElement, rhs: BodyInputElement) -> Bool {
+        if case let .view(lhsBody) = lhs, case let .view(rhsBody) = rhs {
+            compareValues(lhsBody, rhsBody, options: .init(rawValue: 0x103))
+        } else if case let .list(lhsBody) = lhs, case let .list(rhsBody) = rhs{
+            compareValues(lhsBody, rhsBody, options: .init(rawValue: 0x103))
+        } else {
+            false
+        }
+    }
+
+    static var isTriviallyReusable: Bool {
+        _SemanticFeature_v5.isEnabled
+    }
+
+    func makeReusable(indirectMap: IndirectAttributeMap) {
+        return
+    }
+
+    func tryToReuse(by other: BodyInputElement, indirectMap: IndirectAttributeMap, testOnly: Bool) -> Bool {
+        switch self {
+            case let .view(makeViewBody):
+                guard case let .view(otherMakeViewBody) = other else {
+                    ReuseTrace.traceReuseInternalFailure()
+                    return false
+                }
+                return Self.isTriviallyReusable || compareValues(makeViewBody, otherMakeViewBody, options: .init(rawValue: 0x103))
+            case let .list(makeViewListBody):
+                guard case let .list(otherMakeViewListBody) = other else {
+                    ReuseTrace.traceReuseInternalFailure()
+                    return false
+                }
+                return Self.isTriviallyReusable || compareValues(makeViewListBody, otherMakeViewListBody, options: .init(rawValue: 0x103))
+        }
+    }
+}
+
+
+private struct BodyCountInput<V>: ViewInput {
+    static var defaultValue: Stack<_ViewListCountInputs> { .init() }
+}

Sources/OpenSwiftUICore/Modifier/ViewModifier/ViewModifier.swift

@@ -120,9 +120,7 @@ extension ViewModifier where Self: _GraphInputsModifier, Body == Never {
         body: @escaping (_Graph, _ViewListInputs) -> _ViewListOutputs
     ) -> _ViewListOutputs {
         var inputs = inputs
-        inputs.withMutateGraphInputs { inputs in
-            _makeInputs(modifier: modifier, inputs: &inputs)
-        }
+        _makeInputs(modifier: modifier, inputs: &inputs.base)
         let outputs = body(_Graph(), inputs)
         return outputs
     }

Sources/OpenSwiftUICore/Render/DisplayList/DisplayList_StableIdentity.swift

@@ -134,7 +134,7 @@ extension _GraphInputs {
         pushScope(id: makeStableTypeData(type))
     }
 
-    package var stableIDScope: WeakAttribute<_DisplayList_StableIdentityScope>? {
+    package var stableIDScope: WeakAttribute<DisplayList.StableIdentityScope>? {
         guard !options.contains(.needsStableDisplayListIDs) else {
             return nil
         }

Sources/OpenSwiftUICore/View/AnyView.swift

@@ -323,6 +323,10 @@ private struct AnyViewList: StatefulRule, AsyncAttribute {
     }
 
     struct Transform: _ViewList_SublistTransform_Item {
+        func bindID(_ id: inout _ViewList_ID) {
+            // TODO
+        }
+
         func apply(sublist: inout _ViewList_Sublist) {
             item.bindID(&sublist.id)
             sublist.elements = item.wrapping(sublist.elements)

Sources/OpenSwiftUICore/View/CustomView.swift

@@ -44,9 +44,7 @@ extension View {
     nonisolated package static func makeViewList(view: _GraphValue<Self>, inputs: _ViewListInputs) -> _ViewListOutputs {
         let fields = DynamicPropertyCache.fields(of: Self.self)
         var inputs = inputs
-        let (body, buffer) = inputs.withMutateGraphInputs { inputs in
-            makeBody(view: view, inputs: &inputs, fields: fields)
-        }
+        let (body, buffer) = makeBody(view: view, inputs: &inputs.base, fields: fields)
         let outputs = Body.makeDebuggableViewList(view: body, inputs: inputs)
         if let buffer {
             buffer.traceMountedProperties(to: body, fields: fields)

Sources/OpenSwiftUICore/View/EmptyView.swift

@@ -36,10 +36,7 @@ public struct EmptyView: PrimitiveView {
     }
 
     public static func _makeViewList(view: _GraphValue<EmptyView>, inputs: _ViewListInputs) -> _ViewListOutputs {
-        guard inputs.options.contains(.isNonEmptyParent) else {
-            return _ViewListOutputs.emptyParentViewList(inputs: inputs)
-        }
-        return _ViewListOutputs.nonEmptyParentViewList(inputs: inputs)
+        .emptyViewList(inputs: inputs)
     }
 
     public static func _viewListCount(inputs: _ViewListCountInputs) -> Int? {