cr feedback: refactor switch statement

Author: benpious

stdlib/public/core/KeyPath.swift

@@ -3744,10 +3744,10 @@ fileprivate func dynamicLibraryAddress<Base, Leaf>(
 
 @available(SwiftStdLib 5.7, *)
 extension AnyKeyPath: CustomDebugStringConvertible {
-        
+    
     @available(SwiftStdLib 5.7, *)
     public var debugDescription: String {
-        #if SWIFT_ENABLE_REFLECTION
+#if SWIFT_ENABLE_REFLECTION
         var description = "\\\(String(describing: Self.rootType))"
         return withBuffer {
             var buffer = $0
@@ -3759,83 +3759,57 @@ extension AnyKeyPath: CustomDebugStringConvertible {
                 let (rawComponent, optNextType) = buffer.next()
                 let hasEnded = optNextType == nil
                 let nextType = optNextType ?? Self.valueType
-                func name(for offset: Int) -> String {
+                switch rawComponent.value {
+                case .optionalForce, .optionalWrap, .optionalChain:
+                    break
+                default:
+                    description.append(".")
+                }
+                switch rawComponent.value {
+                case .class(let offset),
+                        .struct(let offset):
                     let count = _getRecursiveChildCount(valueType)
-                    for i in 0..<count {
-                        if _getChildOffset(
-                            valueType,
-                            index: i
-                        ) == offset {
-                            var field = _FieldReflectionMetadata()
-                            _ = _getChildMetadata(
+                    let index = (0..<count)
+                        .first(where: { i in
+                            _getChildOffset(
                                 valueType,
-                                index: i,
-                                fieldMetadata: &field
-                            )
-                            defer {
-                                field.freeFunc?(field.name)
-                            }
-                            return String(cString: field.name)
+                                index: i
+                            ) == offset
+                        })
+                    if let index = index {
+                        var field = _FieldReflectionMetadata()
+                        _ = _getChildMetadata(
+                            valueType,
+                            index: index,
+                            fieldMetadata: &field
+                        )
+                        defer {
+                            field.freeFunc?(field.name)
                         }
+                        description.append(String(cString: field.name))
+                    } else {
+                        description.append("<offset \(offset) (\(nextType))>")
                     }
-                    return "<offset \(offset) (\(nextType))>"
-                }
-                func name(
-                    for pointer: ComputedAccessorsPtr,
-                    base: Any.Type,
-                    leaf: Any.Type
-                ) -> String {
+                case .get(_, let accessors, _),
+                        .nonmutatingGetSet(_, let accessors, _),
+                        .mutatingGetSet(_, let accessors, _):
                     func project<Base>(base: Base.Type) -> String {
                         func project2<Leaf>(leaf: Leaf.Type) -> String {
                             dynamicLibraryAddress(
-                                of: pointer,
+                                of: accessors,
                                 base,
                                 leaf
                             )
                         }
                         return _openExistential(nextType, do: project2)
                     }
-                    return _openExistential(base, do: project)
-                }
-                switch rawComponent.value {
-                case .optionalForce, .optionalWrap, .optionalChain:
-                    break
-                default:
-                    description.append(".")
-                }
-                switch rawComponent.value {
-                case .class(let offset):
-                    description.append(name(for: offset))
-                case .get(_, let accessors, _):
                     description.append(
-                        name(
-                            for: accessors,
-                            base: valueType,
-                            leaf: nextType
-                        )
-                    )
-                case .mutatingGetSet(_, let accessors, _):
-                    description.append(
-                        name(
-                            for: accessors,
-                            base: valueType,
-                            leaf: nextType
-                        )
-                    )
-                case .nonmutatingGetSet(_, let accessors, _):
-                    description.append(
-                        name(
-                            for: accessors,
-                            base: valueType,
-                            leaf: nextType
-                        )
+                        _openExistential(valueType, do: project)
                     )
                 case .optionalChain, .optionalWrap:
                     description.append("?")
                 case .optionalForce:
                     description.append("!")
-                case .struct(let offset):
-                    description.append(name(for: offset))
                 }
                 if hasEnded {
                     break