Merge pull request #193 from lorentey/fleshing-out-PersistentSet

Fleshing out `PersistentSet`

Author: lorentey

Sources/PersistentCollections/Node/_Node+Builder.swift

@@ -59,9 +59,9 @@ extension _Node.Builder {
     assert(level.isAtRoot)
     switch self {
     case .empty:
-      return _Node(storage: _emptySingleton, count: 0)
+      return ._empty()
     case .item(let item, let h):
-      return _Node._regularNode(item, h[level])
+      return ._regularNode(item, h[level])
     case .node(let node, _):
       return node
     }

Sources/PersistentCollections/Node/_Node+Initializers.swift

@@ -10,6 +10,11 @@
 //===----------------------------------------------------------------------===//
 
 extension _Node {
+  @inlinable @inline(__always)
+  internal static func _empty() -> _Node {
+    _Node(storage: _emptySingleton, count: 0)
+  }
+
   @inlinable
   internal static func _collisionNode(
     _ hash: _Hash,

Sources/PersistentCollections/Node/_Node+Structural intersection.swift

@@ -11,10 +11,10 @@
 
 extension _Node {
   @inlinable
-  internal func intersection(
+  internal func intersection<Value2>(
     _ level: _Level,
     _ hashPrefix: _Hash,
-    _ other: _Node
+    _ other: _Node<Key, Value2>
   ) -> Builder? {
     if self.raw.storage === other.raw.storage { return nil }
 
@@ -102,10 +102,10 @@ extension _Node {
   }
 
   @inlinable @inline(never)
-  internal func _intersection_slow(
+  internal func _intersection_slow<Value2>(
     _ level: _Level,
     _ hashPrefix: _Hash,
-    _ other: _Node
+    _ other: _Node<Key, Value2>
   ) -> Builder? {
     let lc = self.isCollisionNode
     let rc = other.isCollisionNode

Sources/PersistentCollections/Node/_Node+Structural subtracting.swift

@@ -11,10 +11,10 @@
 
 extension _Node {
   @inlinable
-  internal func subtracting(
+  internal func subtracting<Value2>(
     _ level: _Level,
     _ hashPrefix: _Hash,
-    _ other: _Node
+    _ other: _Node<Key, Value2>
   ) -> Builder? {
     if self.raw.storage === other.raw.storage { return .empty }
 
@@ -107,10 +107,10 @@ extension _Node {
   }
 
   @inlinable @inline(never)
-  internal func _subtracting_slow(
+  internal func _subtracting_slow<Value2>(
     _ level: _Level,
     _ hashPrefix: _Hash,
-    _ other: _Node
+    _ other: _Node<Key, Value2>
   ) -> Builder? {
     let lc = self.isCollisionNode
     let rc = other.isCollisionNode

Sources/PersistentCollections/Node/_Node+Subtree Insertions.swift

@@ -12,6 +12,15 @@
 import _CollectionsUtilities
 
 extension _Node {
+  @inlinable
+  internal mutating func insert(
+    _ level: _Level,
+    _ item: Element,
+    _ hash: _Hash
+  ) -> (inserted: Bool, leaf: _UnmanagedNode, slot: _Slot) {
+    insert(level, item.key, hash) { $0.initialize(to: item) }
+  }
+
   @inlinable
   internal mutating func insert(
     _ level: _Level,

Sources/PersistentCollections/PersistentDictionary/PersistentDictionary+Collection.swift

@@ -109,7 +109,7 @@ extension PersistentDictionary: BidirectionalCollection {
   public subscript(i: Index) -> Element {
     precondition(_isValid(i), "Invalid index")
     precondition(i._path.isOnItem, "Can't get element at endIndex")
-    return _Node.UnsafeHandle.read(i._path.node) {
+    return _UnsafeHandle.read(i._path.node) {
       $0[item: i._path.currentItemSlot]
     }
   }

Sources/PersistentCollections/PersistentDictionary/PersistentDictionary+Initializers.swift

@@ -12,7 +12,7 @@
 extension PersistentDictionary {
   @inlinable
   public init() {
-    self.init(_new: _Node(storage: _emptySingleton, count: 0))
+    self.init(_new: ._empty())
   }
 
   @inlinable
@@ -37,9 +37,7 @@ extension PersistentDictionary {
     self.init()
     for item in keysAndValues {
       let hash = _Hash(item.0)
-      let r = _root.insert(.top, item.0, hash) {
-        $0.initialize(to: item)
-      }
+      let r = _root.insert(.top, item, hash)
       precondition(r.inserted, "Duplicate key: '\(item.0)'")
     }
     _invariantCheck()

Sources/PersistentCollections/PersistentDictionary/PersistentDictionary+Values.swift

@@ -16,6 +16,9 @@ extension PersistentDictionary {
     @usableFromInline
     internal typealias _Node = PersistentCollections._Node<Key, Value>
 
+    @usableFromInline
+    internal typealias _UnsafeHandle = _Node.UnsafeHandle
+
     @usableFromInline
     internal var _base: PersistentDictionary
 
@@ -108,14 +111,14 @@ extension PersistentDictionary.Values: BidirectionalCollection {
       precondition(_base._isValid(index), "Invalid index")
       precondition(index._path.isOnItem, "Cannot set value at end index")
       let (leaf, slot) = _base._root.ensureUnique(level: .top, at: index._path)
-      _Node.UnsafeHandle.update(leaf) { $0[item: slot].value = newValue }
+      _UnsafeHandle.update(leaf) { $0[item: slot].value = newValue }
       _base._invalidateIndices()
     }
     _modify { // FIXME: Consider removing
       precondition(_base._isValid(index), "Invalid index")
       precondition(index._path.isOnItem, "Cannot set value at end index")
       let (leaf, slot) = _base._root.ensureUnique(level: .top, at: index._path)
-      var item = _Node.UnsafeHandle.update(leaf) { $0.itemPtr(at: slot).move() }
+      var item = _UnsafeHandle.update(leaf) { $0.itemPtr(at: slot).move() }
       defer {
         _Node.UnsafeHandle.update(leaf) {
           $0.itemPtr(at: slot).initialize(to: item)

Sources/PersistentCollections/PersistentDictionary/PersistentDictionary.swift

@@ -13,6 +13,9 @@ public struct PersistentDictionary<Key: Hashable, Value> {
   @usableFromInline
   internal typealias _Node = PersistentCollections._Node<Key, Value>
 
+  @usableFromInline
+  internal typealias _UnsafeHandle = _Node.UnsafeHandle
+
   @usableFromInline
   var _root: _Node
 
@@ -284,7 +287,7 @@ extension PersistentDictionary {
     }
     _invalidateIndices()
     if r.inserted { return nil }
-    return _Node.UnsafeHandle.update(r.leaf) {
+    return _UnsafeHandle.update(r.leaf) {
       let p = $0.itemPtr(at: r.slot)
       let old = p.pointee.value
       p.pointee.value = value
@@ -302,7 +305,7 @@ extension PersistentDictionary {
       $0.initialize(to: (key, value))
     }
     if r.inserted { return true }
-    _Node.UnsafeHandle.update(r.leaf) {
+    _UnsafeHandle.update(r.leaf) {
       $0[item: r.slot].value = value
     }
     return false
@@ -335,7 +338,7 @@ extension PersistentDictionary {
     let r = _root.updateValue(.top, forKey: key, hash) {
       $0.initialize(to: (key, defaultValue()))
     }
-    return try _Node.UnsafeHandle.update(r.leaf) {
+    return try _UnsafeHandle.update(r.leaf) {
       try body(&$0[item: r.slot].value)
     }
   }

Sources/PersistentCollections/PersistentSet/PersistentSet+Collection.swift

@@ -109,7 +109,7 @@ extension PersistentSet: BidirectionalCollection {
   public subscript(i: Index) -> Element {
     precondition(_isValid(i), "Invalid index")
     precondition(i._path.isOnItem, "Can't get element at endIndex")
-    return _Node.UnsafeHandle.read(i._path.node) {
+    return _UnsafeHandle.read(i._path.node) {
       $0[item: i._path.currentItemSlot].key
     }
   }
@@ -173,4 +173,43 @@ extension PersistentSet: BidirectionalCollection {
     precondition(limited, "Index offset out of bounds")
     return nil
   }
+
+  @inlinable @inline(__always)
+  public func _customIndexOfEquatableElement(
+    _ element: Element
+  ) -> Index?? {
+    _index(of: element)
+  }
+
+  @inlinable @inline(__always)
+  public func _customLastIndexOfEquatableElement(
+    _ element: Element
+  ) -> Index?? {
+    _index(of: element)
+  }
+
+  @inlinable
+  internal func _index(of element: Element) -> Index? {
+    let hash = _Hash(element)
+    guard let path = _root.path(to: element, hash) else { return nil }
+    return Index(_root: _root.unmanaged, version: _version, path: path)
+  }
+
+  public func _failEarlyRangeCheck(
+    _ index: Index, bounds: Range<Index>
+  ) {
+    precondition(_isValid(index))
+  }
+
+  public func _failEarlyRangeCheck(
+    _ index: Index, bounds: ClosedRange<Index>
+  ) {
+    precondition(_isValid(index))
+  }
+
+  public func _failEarlyRangeCheck(
+    _ range: Range<Index>, bounds: Range<Index>
+  ) {
+    precondition(_isValid(range.lowerBound) && _isValid(range.upperBound))
+  }
 }