Use single constructor for IndexExpressionImpl.

So, that we can generate the constructor and the whole class.

Change-Id: I71c2431425a64122c89a9f1ed7c30f717e5fb79b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/428084
Reviewed-by: Paul Berry <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

Author: scheglov

pkg/analyzer/lib/src/clients/dart_style/rewrite_cascade.dart

@@ -67,11 +67,12 @@ ExpressionImpl insertCascadeTargetIntoExpression({
       question = _synthesizeToken(TokenType.QUESTION, expression.period!);
     }
 
-    return IndexExpressionImpl.forTarget(
+    return IndexExpressionImpl(
       target: insertCascadeTargetIntoExpression(
         expression: expressionTarget,
         cascadeTarget: cascadeTarget,
       ),
+      period: null,
       question: question,
       leftBracket: expression.leftBracket,
       index: expression.index,

pkg/analyzer/lib/src/dart/ast/ast.dart

@@ -11095,22 +11095,9 @@ final class IndexExpressionImpl extends ExpressionImpl
   @override
   MethodElement? element;
 
-  /// Initializes a newly created index expression that is a child of a cascade
-  /// expression.
-  IndexExpressionImpl.forCascade({
-    required this.period,
-    required this.question,
-    required this.leftBracket,
-    required ExpressionImpl index,
-    required this.rightBracket,
-  }) : _index = index {
-    _becomeParentOf(_index);
-  }
-
-  /// Initializes a newly created index expression that isn't a child of a
-  /// cascade expression.
-  IndexExpressionImpl.forTarget({
+  IndexExpressionImpl({
     required ExpressionImpl? target,
+    required this.period,
     required this.question,
     required this.leftBracket,
     required ExpressionImpl index,

pkg/analyzer/lib/src/fasta/ast_builder.dart

@@ -4890,7 +4890,8 @@ class AstBuilder extends StackListener {
       var receiver = pop() as CascadeExpressionImpl;
       var token = peek() as Token;
       push(receiver);
-      var expression = IndexExpressionImpl.forCascade(
+      var expression = IndexExpressionImpl(
+        target: null,
         period: token,
         question: question,
         leftBracket: leftBracket,
@@ -4901,8 +4902,9 @@ class AstBuilder extends StackListener {
       push(expression);
     } else {
       push(
-        IndexExpressionImpl.forTarget(
+        IndexExpressionImpl(
           target: target,
+          period: null,
           question: question,
           leftBracket: leftBracket,
           index: index,

pkg/analyzer/lib/src/summary2/ast_binary_reader.dart

@@ -761,28 +761,14 @@ class AstBinaryReader {
     var flags = _readByte();
     var target = _readOptionalNode() as ExpressionImpl?;
     var index = readNode() as ExpressionImpl;
-    // TODO(scheglov): Is this clumsy?
-    IndexExpressionImpl node;
-    if (target != null) {
-      node = (IndexExpressionImpl.forTarget(
-          target: target,
-          question:
-              AstBinaryFlags.hasQuestion(flags) ? Tokens.question() : null,
-          leftBracket: Tokens.openSquareBracket(),
-          index: index,
-          rightBracket: Tokens.closeSquareBracket(),
-        ))
-        ..period =
-            AstBinaryFlags.hasPeriod(flags) ? Tokens.periodPeriod() : null;
-    } else {
-      node = IndexExpressionImpl.forCascade(
-        period: Tokens.periodPeriod(),
-        question: AstBinaryFlags.hasQuestion(flags) ? Tokens.question() : null,
-        leftBracket: Tokens.openSquareBracket(),
-        index: index,
-        rightBracket: Tokens.closeSquareBracket(),
-      );
-    }
+    var node = IndexExpressionImpl(
+      target: target,
+      period: AstBinaryFlags.hasPeriod(flags) ? Tokens.periodPeriod() : null,
+      question: AstBinaryFlags.hasQuestion(flags) ? Tokens.question() : null,
+      leftBracket: Tokens.openSquareBracket(),
+      index: index,
+      rightBracket: Tokens.closeSquareBracket(),
+    );
     node.element = _reader.readElement2() as MethodElement?;
     _readExpressionResolution(node);
     return node;