nullable safe calls supported (for methods and instances)

src/org/jetbrains/jet/j2k/ast/MethodCallExpression.java

@@ -8,10 +8,17 @@ import org.jetbrains.annotations.NotNull;
 public class MethodCallExpression extends Expression {
   private final Expression myMethodCall;
   private final Element myParamList;
+  private boolean myIsResultNullable;
 
-  public MethodCallExpression(Expression methodCall, Element paramList) {
+  public MethodCallExpression(Expression methodCall, Element paramList, boolean nullable) {
     myMethodCall = methodCall;
     myParamList = paramList;
+    myIsResultNullable = nullable;
+  }
+
+  @Override
+  public boolean isNullable() {
+    return myIsResultNullable;
   }
 
   @NotNull

src/org/jetbrains/jet/j2k/ast/PrimitiveType.java

@@ -12,6 +12,11 @@ public class PrimitiveType extends Type {
     myType = type;
   }
 
+  @Override
+  public boolean isNullable() {
+    return false;
+  }
+
   @NotNull
   @Override
   public String toKotlin() {

src/org/jetbrains/jet/j2k/ast/Type.java

@@ -19,7 +19,7 @@ public abstract class Type extends Element {
     myNullable = nullable;
   }
 
-  boolean isNullable() {
+  public boolean isNullable() {
     return myNullable;
   }
 
@@ -36,5 +36,10 @@ public abstract class Type extends Element {
     public String toKotlin() {
       return "UNRESOLVED_TYPE";
     }
+
+    @Override
+    public boolean isNullable() {
+      return false;
+    }
   }
 }

src/org/jetbrains/jet/j2k/visitors/ExpressionVisitor.java

@@ -165,7 +165,8 @@ public class ExpressionVisitor extends StatementVisitor implements Visitor {
     myResult = // TODO: not resolved
       new MethodCallExpression(
         expressionToExpression(expression.getMethodExpression()),
-        elementToElement(expression.getArgumentList())
+        elementToElement(expression.getArgumentList()),
+        typeToType(expression.getType()).isNullable()
       );
   }
 
@@ -225,11 +226,11 @@ public class ExpressionVisitor extends StatementVisitor implements Visitor {
   @Override
   public void visitReferenceExpression(PsiReferenceExpression expression) {
     super.visitReferenceExpression(expression);
-    final IdentifierImpl identifier = expression.getType() != null ? // TODO: if type exists so id is nullable
-      new IdentifierImpl(expression.getReferenceName()) :
-      new IdentifierImpl(expression.getReferenceName(), false);
-
-    myResult = new CallChain(expressionToExpression(expression.getQualifierExpression()), identifier);
+    boolean isNullable = typeToType(expression.getType()).isNullable();
+    myResult = new CallChain(
+      expressionToExpression(expression.getQualifierExpression()),
+      new IdentifierImpl(expression.getReferenceName(), isNullable) // TODO: if type exists so id is nullable
+    );
   }
 
   @Override

testData/ast/callChain/file/libraryMethodCall.jav

@@ -0,0 +1,12 @@
+class Library {
+  static void call() {}
+
+  static String getString() { return ""; }
+}
+
+class User {
+  void main() {
+    Library.call();
+    Library.getString().isEmpty();
+  }
+}

testData/ast/callChain/file/libraryMethodCall.kt

@@ -0,0 +1,17 @@
+namespace {
+open class Library {
+class object {
+fun call() : Unit {
+}
+fun getString() : String? {
+return ""
+}
+}
+}
+open class User {
+fun main() : Unit {
+Library.call()
+Library.getString()?.isEmpty()
+}
+}
+}

testData/ast/callChain/file/libraryMethodCallFromInstance.jav

@@ -0,0 +1,16 @@
+class Library {
+  void call() {}
+
+  String getString() { return ""; }
+}
+
+class User {
+  void main() {
+    Library lib = new Library();
+    lib.call();
+    lib.getString().isEmpty();
+
+    new Library().call();
+    new Library().getString().isEmpty();
+  }
+}

testData/ast/callChain/file/libraryMethodCallFromInstance.kt

@@ -0,0 +1,18 @@
+namespace {
+open class Library {
+fun call() : Unit {
+}
+fun getString() : String? {
+return ""
+}
+}
+open class User {
+fun main() : Unit {
+var lib : Library? = Library()
+lib?.call()
+lib?.getString()?.isEmpty()
+Library().call()
+Library().getString()?.isEmpty()
+}
+}
+}

testData/ast/callChain/file/libraryStringFieldCall.jav

@@ -0,0 +1,9 @@
+class Library {
+  final public String myString;
+}
+
+class User {
+  void main() {
+    Library.myString.isEmpty();
+  }
+}

testData/ast/callChain/file/libraryStringFieldCall.kt

@@ -0,0 +1,10 @@
+namespace {
+open class Library {
+public val myString : String?
+}
+open class User {
+fun main() : Unit {
+Library.myString?.isEmpty()
+}
+}
+}