[parser] Push handleEndingBinaryExpression implementation into subclasses

This moves implementation handling calls to handleEndingBinaryExpression into its own method in the subclasses. This splits the `.`, `.?`, `..` and `?..` from the real binary expressions.

This is a step towards handling `a.b` different from `a + b` in the parser such that listeners don't have to create a value for `b` the works in both use cases; in the first is just a named operation performed on the receiver, whereas in the second case it is a full expression in its own right.

Change-Id: I5291439f333971b7ff482325a15502e4d8a66b71
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/442820
Reviewed-by: Jens Johansen <[email protected]>
Commit-Queue: Johnni Winther <[email protected]>

Author: johnniwinther

pkg/_fe_analyzer_shared/lib/src/metadata/parser.dart

@@ -375,7 +375,24 @@ class AnnotationsListener extends StackListener {
 
   @override
   void handleEndingBinaryExpression(Token token, Token endToken) {
-    endBinaryExpression(token, endToken);
+    assert(
+    checkState(token, [
+      /* right */ _ValueKinds._Proto,
+      /* left */ _ValueKinds._Proto,
+    ]),
+    );
+    Proto right = pop() as Proto;
+    Proto left = pop() as Proto;
+    switch (token.lexeme) {
+      case '.':
+        IdentifierProto identifierProto = right as IdentifierProto;
+        push(left.apply(identifierProto));
+      case '?.':
+        IdentifierProto identifierProto = right as IdentifierProto;
+        push(left.apply(identifierProto, isNullAware: true));
+      default:
+        throw new UnimplementedError("Binary operator '${token.lexeme}'.");
+    }
   }
 
   @override
@@ -389,12 +406,6 @@ class AnnotationsListener extends StackListener {
     Proto right = pop() as Proto;
     Proto left = pop() as Proto;
     switch (token.lexeme) {
-      case '.':
-        IdentifierProto identifierProto = right as IdentifierProto;
-        push(left.apply(identifierProto));
-      case '?.':
-        IdentifierProto identifierProto = right as IdentifierProto;
-        push(left.apply(identifierProto, isNullAware: true));
       case '??':
         push(
           new ExpressionProto(

pkg/_fe_analyzer_shared/lib/src/parser/listener.dart

@@ -2075,10 +2075,7 @@ class Listener implements UnescapeErrorListener {
   }
 
   /// Called for `.`, `?.` and `..`.
-  void handleEndingBinaryExpression(Token token, Token endToken) {
-    // TODO(jensj): push implementation into subclasses
-    endBinaryExpression(token, endToken);
-  }
+  void handleEndingBinaryExpression(Token token, Token endToken) {}
 
   /// Called when the parser encounters a `?` operator and begins parsing a
   /// conditional expression.

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

@@ -1069,37 +1069,26 @@ class AstBuilder extends StackListener {
   void endBinaryExpression(Token operatorToken, Token endToken) {
     assert(
       operatorToken.isOperator ||
-          optional('.', operatorToken) ||
-          optional('?.', operatorToken) ||
-          optional('..', operatorToken) ||
-          optional('?..', operatorToken) ||
           optional('===', operatorToken) ||
           optional('!==', operatorToken),
     );
     debugEvent("BinaryExpression");
 
-    if (identical(".", operatorToken.stringValue) ||
-        identical("?.", operatorToken.stringValue) ||
-        identical("..", operatorToken.stringValue) ||
-        identical("?..", operatorToken.stringValue)) {
-      doDotExpression(operatorToken);
-    } else {
-      var right = pop() as ExpressionImpl;
-      var left = pop() as ExpressionImpl;
-      reportErrorIfSuper(right);
-      push(
-        BinaryExpressionImpl(
-          leftOperand: left,
-          operator: operatorToken,
-          rightOperand: right,
-        ),
+    var right = pop() as ExpressionImpl;
+    var left = pop() as ExpressionImpl;
+    reportErrorIfSuper(right);
+    push(
+      BinaryExpressionImpl(
+        leftOperand: left,
+        operator: operatorToken,
+        rightOperand: right,
+      ),
+    );
+    if (!enableTripleShift && operatorToken.type == TokenType.GT_GT_GT) {
+      _reportFeatureNotEnabled(
+        feature: ExperimentalFeatures.triple_shift,
+        startToken: operatorToken,
       );
-      if (!enableTripleShift && operatorToken.type == TokenType.GT_GT_GT) {
-        _reportFeatureNotEnabled(
-          feature: ExperimentalFeatures.triple_shift,
-          startToken: operatorToken,
-        );
-      }
     }
   }
 
@@ -4363,6 +4352,19 @@ class AstBuilder extends StackListener {
     push(EmptyStatementImpl(semicolon: semicolon));
   }
 
+  @override
+  void handleEndingBinaryExpression(Token operatorToken, Token endToken) {
+    assert(
+      optional('.', operatorToken) ||
+          optional('?.', operatorToken) ||
+          optional('..', operatorToken) ||
+          optional('?..', operatorToken),
+    );
+    debugEvent("EndingBinaryExpression");
+
+    doDotExpression(operatorToken);
+  }
+
   @override
   void handleEnumElement(Token beginToken, Token? augmentToken) {
     debugEvent("EnumElement");

pkg/analyzer/tool/summary/mini_ast.dart

@@ -219,19 +219,9 @@ class MiniAstBuilder extends StackListener {
   void endBinaryExpression(Token token, Token endToken) {
     debugEvent("BinaryExpression");
 
-    if (identical('.', token.stringValue)) {
-      var rightOperand = pop() as String;
-      var leftOperand = pop();
-      if (leftOperand is String && !leftOperand.contains('.')) {
-        push(PrefixedIdentifier(leftOperand, token, rightOperand));
-      } else {
-        push(UnknownExpression());
-      }
-    } else {
-      pop(); // RHS
-      pop(); // LHS
-      push(UnknownExpression());
-    }
+    pop(); // RHS
+    pop(); // LHS
+    push(UnknownExpression());
   }
 
   @override
@@ -478,6 +468,25 @@ class MiniAstBuilder extends StackListener {
     debugEvent("ClassWithClause");
   }
 
+  @override
+  void handleEndingBinaryExpression(Token token, Token endToken) {
+    debugEvent("EndingBinaryExpression");
+
+    if (identical('.', token.stringValue)) {
+      var rightOperand = pop() as String;
+      var leftOperand = pop();
+      if (leftOperand is String && !leftOperand.contains('.')) {
+        push(PrefixedIdentifier(leftOperand, token, rightOperand));
+      } else {
+        push(UnknownExpression());
+      }
+    } else {
+      pop(); // RHS
+      pop(); // LHS
+      push(UnknownExpression());
+    }
+  }
+
   @override
   void handleEnumElement(Token beginToken, Token? augmentToken) {
     debugEvent("EnumElement");

pkg/front_end/lib/src/kernel/body_builder.dart

@@ -2553,7 +2553,7 @@ class BodyBuilder extends StackListenerImpl
   }
 
   @override
-  void endBinaryExpression(Token token, Token endToken) {
+  void handleEndingBinaryExpression(Token token, Token endToken) {
     assert(checkState(token, [
       unionOfKinds([
         ValueKinds.Expression,
@@ -2566,13 +2566,35 @@ class BodyBuilder extends StackListenerImpl
         token.isA(TokenType.PERIOD_PERIOD) ||
         token.isA(TokenType.QUESTION_PERIOD_PERIOD)) {
       doDotOrCascadeExpression(token);
-    } else if (token.isA(TokenType.AMPERSAND_AMPERSAND) ||
+    } else if (token.isA(TokenType.QUESTION_PERIOD)) {
+      doIfNotNull(token);
+    } else {
+      throw new UnsupportedError("Unexpected ending binary $token.");
+    }
+    assert(checkState(token, [
+      unionOfKinds([
+        ValueKinds.Expression,
+        ValueKinds.Generator,
+        ValueKinds.Initializer,
+      ]),
+    ]));
+  }
+
+  @override
+  void endBinaryExpression(Token token, Token endToken) {
+    assert(checkState(token, [
+      unionOfKinds([
+        ValueKinds.Expression,
+        ValueKinds.Generator,
+        ValueKinds.Selector,
+      ]),
+    ]));
+    debugEvent("BinaryExpression");
+    if (token.isA(TokenType.AMPERSAND_AMPERSAND) ||
         token.isA(TokenType.BAR_BAR)) {
       doLogicalExpression(token);
     } else if (token.isA(TokenType.QUESTION_QUESTION)) {
       doIfNull(token);
-    } else if (token.isA(TokenType.QUESTION_PERIOD)) {
-      doIfNotNull(token);
     } else {
       doBinaryExpression(token);
     }

pkg/front_end/test/parser/literal_entry_info_test.dart

@@ -915,6 +915,11 @@ class TestInfoListener implements Listener {
     calls.add('beginVariableInitializer $token');
   }
 
+  @override
+  void handleEndingBinaryExpression(Token token, Token endToken) {
+    calls.add('handleEndingBinaryExpression $token');
+  }
+
   @override
   void endBinaryExpression(Token token, Token endToken) {
     calls.add('endBinaryExpression $token');