Remove child(at:) and hasChild methods from RawSyntaxLayoutView

Author: ahoppen

Sources/SwiftSyntax/Raw/RawSyntaxLayoutView.swift

@@ -149,21 +149,12 @@ struct RawSyntaxLayoutView {
     }
   }
 
-  func child(at index: Int) -> RawSyntax? {
-    guard hasChild(at: index) else { return nil }
-    return children[index]
-  }
-
-  func hasChild(at index: Int) -> Bool {
-    children[index] != nil
-  }
-
   /// Returns the child at the provided cursor in the layout.
   /// - Parameter index: The index of the child you're accessing.
   /// - Returns: The child at the provided index.
   subscript<CursorType: RawRepresentable>(_ index: CursorType) -> RawSyntax?
     where CursorType.RawValue == Int {
-    return child(at: index.rawValue)
+    return children[index.rawValue]
   }
 
   /// The number of children, `present` or `missing`, in this node.

Sources/SwiftSyntax/SyntaxChildren.swift

@@ -172,14 +172,14 @@ struct RawSyntaxChildren: BidirectionalCollection {
   }
 
   func index(after index: SyntaxChildrenIndex) -> SyntaxChildrenIndex {
-    let node = parent.layoutView!.child(at: Int(index.data!.indexInParent))
+    let node = parent.layoutView!.children[Int(index.data!.indexInParent)]
     return self.index(index, advancedBy: node)
   }
 
   func index(before index: SyntaxChildrenIndex) -> SyntaxChildrenIndex {
     if let index = index.data {
       // We are reversing a non-end index.
-      let previousNode = parent.layoutView!.child(at: Int(index.indexInParent - 1))
+      let previousNode = parent.layoutView!.children[Int(index.indexInParent - 1)]
       let previousNodeLength = UInt32(previousNode?.totalLength.utf8Length ?? 0)
       let reversedIndexInTree = index.indexInTree.reversedBy(previousNode)
       return SyntaxChildrenIndex(offset: index.offset - previousNodeLength,
@@ -231,7 +231,7 @@ struct RawSyntaxChildren: BidirectionalCollection {
     // Accessing the end index is undefined. So we can assume a non-end index.
     let index = index.data!
 
-    let child = parent.layoutView!.child(at: Int(index.indexInParent))
+    let child = parent.layoutView!.children[Int(index.indexInParent)]
     let info = AbsoluteSyntaxInfo(index: index, rootId: rootId)
     return (child, info)
   }

Sources/SwiftSyntax/SyntaxClassifier.swift

@@ -118,8 +118,7 @@ fileprivate struct AbsoluteNode {
   var firstChild: AbsoluteNode? {
     guard let layoutView = raw.layoutView else { return nil }
     var curPos = position.advancedToFirstChild()
-    for i in 0..<layoutView.children.count {
-      let childOpt = layoutView.child(at: i)
+    for childOpt in layoutView.children {
       if let child = childOpt, viewMode.shouldTraverse(node: child) {
         return AbsoluteNode(raw: child, position: curPos, parent: self)
       }
@@ -130,9 +129,7 @@ fileprivate struct AbsoluteNode {
 
   func nextSibling(parent: AbsoluteNode) -> AbsoluteNode? {
     var curPos = position.advancedBySibling(raw)
-    let parentLayoutView = parent.raw.layoutView!
-    for i in Int(position.indexInParent+1) ..< parentLayoutView.children.count {
-      let siblingOpt = parent.raw.layoutView!.child(at: i)
+    for siblingOpt in parent.raw.layoutView!.children.dropFirst(Int(position.indexInParent + 1)) {
       if let sibling = siblingOpt, viewMode.shouldTraverse(node: sibling) {
         return AbsoluteNode(raw: sibling, position: curPos, parent: parent)
       }

Sources/SwiftSyntax/SyntaxData.swift

@@ -147,8 +147,7 @@ struct AbsoluteRawSyntax {
   func firstChild(viewMode: SyntaxTreeViewMode) -> AbsoluteRawSyntax? {
     guard let layoutView = raw.layoutView else { return nil }
     var curInfo = info.advancedToFirstChild()
-    for i in 0..<layoutView.children.count {
-      let childOpt = layoutView.child(at: i)
+    for childOpt in layoutView.children {
       if let child = childOpt, viewMode.shouldTraverse(node: child) {
         return AbsoluteRawSyntax(raw: child, info: curInfo)
       }
@@ -160,9 +159,7 @@ struct AbsoluteRawSyntax {
   /// Returns next `present` sibling.
   func nextSibling(parent: AbsoluteRawSyntax, viewMode: SyntaxTreeViewMode) -> AbsoluteRawSyntax? {
     var curInfo = info.advancedBySibling(raw)
-    let parentLayoutView = parent.raw.layoutView!
-    for i in Int(info.indexInParent+1) ..< parentLayoutView.children.count {
-      let siblingOpt = parentLayoutView.child(at: i)
+    for siblingOpt in parent.raw.layoutView!.children.dropFirst(Int(info.indexInParent+1)) {
       if let sibling = siblingOpt, viewMode.shouldTraverse(node: sibling) {
         return AbsoluteRawSyntax(raw: sibling, info: curInfo)
       }
@@ -294,7 +291,7 @@ struct SyntaxData {
   ///             normally the Syntax node that this `SyntaxData` belongs to.
   /// - Returns: The child's data at the provided index.
   func child(at index: Int, parent: Syntax) -> SyntaxData? {
-    if !raw.layoutView!.hasChild(at: index) { return nil }
+    if raw.layoutView!.children[index] == nil { return nil }
     var iter = RawSyntaxChildren(absoluteRaw).makeIterator()
     for _ in 0..<index { _ = iter.next() }
     let (raw, info) = iter.next()!

Sources/SwiftSyntax/SyntaxRewriter.swift.gyb

@@ -231,7 +231,7 @@ open class SyntaxRewriter {
           newLayout = ContiguousArray<RawSyntax?>()
           newLayout!.reserveCapacity(node.raw.layoutView!.children.count)
           for j in 0..<childIndex {
-            newLayout!.append(node.raw.layoutView!.child(at: j))
+            newLayout!.append(node.raw.layoutView!.children[j])
           }
         }
 

Sources/SwiftSyntax/gyb_generated/SyntaxRewriter.swift

@@ -5692,7 +5692,7 @@ open class SyntaxRewriter {
           newLayout = ContiguousArray<RawSyntax?>()
           newLayout!.reserveCapacity(node.raw.layoutView!.children.count)
           for j in 0..<childIndex {
-            newLayout!.append(node.raw.layoutView!.child(at: j))
+            newLayout!.append(node.raw.layoutView!.children[j])
           }
         }