More tweaks for 'for' completion.

pkg/analysis_server/lib/src/services/completion/dart/optype.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library services.completion.dart.optype;
 
 import 'package:analysis_server/src/protocol_server.dart' hide Element;
 import 'package:analysis_server/src/provisional/completion/dart/completion_dart.dart';
 import 'package:analysis_server/src/provisional/completion/dart/completion_target.dart';
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 458 matching lines @@
       // Actual: for (var v i^)
       // Parsed: for (var i; i^;)
     } else if (entity is Token &&
         entity.isSynthetic &&
         node.leftSeparator == entity) {
       // Actual: for (String ^)
       // Parsed: for (String; ;)
       //                    ^
       optype.includeVarNameSuggestions = true;
     } else {
-      optype.includeReturnValueSuggestions = true;
-      optype.includeTypeNameSuggestions = true;
-      optype.includeVoidReturnSuggestions = true;
-      // TODO (danrubel) void return suggestions only belong after
-      // the 2nd semicolon.  Return value suggestions only belong after the
-      // first or second semicolon.
+      // for (^) {}
+      // for (Str^ str = null;) {}
+      // In theory it is possible to specify any expression in initializer,
+      // but for any practical use we need only types.
+      if (entity == node.initialization || entity == node.variables) {
+        optype.includeTypeNameSuggestions = true;
+      }
+      // for (; ^) {}
+      if (entity == node.condition) {
+        optype.includeTypeNameSuggestions = true;

[Brian Wilkerson, 2016/05/10 22:29:08]

Seems unlikely to me that we'd want a type in either the condition or the
updaters, but maybe I'm wrong.

+        optype.includeReturnValueSuggestions = true;
+      }
+      // for (; ; ^) {}
+      if (node.updaters.contains(entity)) {
+        optype.includeTypeNameSuggestions = true;
+        optype.includeReturnValueSuggestions = true;
+        optype.includeVoidReturnSuggestions = true;
+      }
     }
   }
 
   @override
   void visitFunctionDeclaration(FunctionDeclaration node) {
     if (identical(entity, node.returnType) ||
         identical(entity, node.name) && node.returnType == null) {
       optype.includeTypeNameSuggestions = true;
     }
   }
@@ skipping 351 matching lines @@
   void visitVariableDeclarationStatement(VariableDeclarationStatement node) {}
 
   @override
   void visitWhileStatement(WhileStatement node) {
     if (identical(entity, node.condition)) {
       optype.includeReturnValueSuggestions = true;
       optype.includeTypeNameSuggestions = true;
     }
   }
 
+  bool _isEntityPrevToken(TokenType expectedType) {
+    Object entity = this.entity;
+    if (entity is SimpleIdentifier && entity.token.isSynthetic) {
+      return entity.token.previous.type == expectedType;
+    }
+    return false;
+  }
+
   bool _isEntityPrevTokenSynthetic() {
     Object entity = this.entity;
     if (entity is AstNode && entity.beginToken.previous?.isSynthetic ?? false) {
       return true;
     }
     return false;
   }
 }