nullable safe calls supported (only for fields)

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

@@ -0,0 +1,32 @@
+package org.jetbrains.jet.j2k.ast;
+
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * @author ignatov
+ */
+public class CallChain extends Expression {
+  private Expression myExpression;
+  private IdentifierImpl myIdentifier;
+
+  public CallChain(Expression expression, IdentifierImpl identifier) {
+    myExpression = expression;
+    myIdentifier = identifier;
+  }
+
+  @Override
+  public boolean isNullable() {
+    return myIdentifier.isNullable();
+  }
+
+  @NotNull
+  @Override
+  public String toKotlin() {
+    if (!myExpression.isEmpty())
+      if (myExpression.isNullable())
+        return myExpression.toKotlin() + QUESTDOT + myIdentifier.toKotlin();
+      else
+        return myExpression.toKotlin() + DOT + myIdentifier.toKotlin();
+    return myIdentifier.toKotlin();
+  }
+}

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

@@ -17,5 +17,18 @@ public abstract class Expression extends Statement {
     public String toKotlin() {
       return EMPTY;
     }
+
+    @Override
+    public boolean isEmpty() {
+      return true;
+    }
+  }
+
+  public boolean isNullable() {
+    return false;
+  }
+
+  public boolean isEmpty() {
+    return false;
   }
 }

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

@@ -7,11 +7,17 @@ import org.jetbrains.annotations.NotNull;
  */
 public class IdentifierImpl extends Expression implements Identifier {
   private final String myName;
+  private boolean myNullable = true;
 
   public IdentifierImpl(String name) {
     myName = name;
   }
 
+  public IdentifierImpl(String name, boolean nullable) {
+    myName = name;
+    myNullable = nullable;
+  }
+
   @Override
   public String getName() {
     return myName;
@@ -26,6 +32,11 @@ public class IdentifierImpl extends Expression implements Identifier {
     return BACKTICK + str + BACKTICK;
   }
 
+  @Override
+  public boolean isNullable() {
+    return myNullable;
+  }
+
   @NotNull
   @Override
   public String toKotlin() {

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

@@ -33,6 +33,7 @@ public abstract class Node implements INode {
   static final String EQUAL = "=";
   static final String EMPTY = "";
   static final String DOT = ".";
+  static final String QUESTDOT = "?.";
   static final String COLON = ":";
   static final String IN = "in";
   static final String AT = "@";

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

@@ -225,7 +225,11 @@ public class ExpressionVisitor extends StatementVisitor implements Visitor {
   @Override
   public void visitReferenceExpression(PsiReferenceExpression expression) {
     super.visitReferenceExpression(expression);
-    myResult = new IdentifierImpl(expression.getQualifiedName()); // TODO
+    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);
   }
 
   @Override

testData/ast/callChain/file/libraryFieldCall.jav

@@ -0,0 +1,9 @@
+class Library {
+  final static java.io.PrintStream ourOut;
+}
+
+class User {
+  void main() {
+    Library.ourOut.print();
+  }
+}

testData/ast/callChain/file/libraryFieldCall.kt

@@ -0,0 +1,12 @@
+namespace {
+open class Library {
+class object {
+val ourOut : PrintStream?
+}
+}
+open class User {
+fun main() : Unit {
+Library.ourOut?.print()
+}
+}
+}

testData/ast/callChain/statement/sout.jav

@@ -0,0 +1 @@
+System.out.println("Hello, world");

testData/ast/callChain/statement/sout.kt

@@ -0,0 +1 @@
+System.`out`?.println("Hello, world")

testData/ast/enum/class/runnableImplementation.kt

@@ -5,6 +5,6 @@ RED
 YELLOW
 BLUE
 override public fun run() : Unit {
-System.out.println(("name()=" + name() + ", toString()=" + toString()))
+System.`out`?.println(("name()=" + name() + ", toString()=" + toString()))
 }
 }

testData/ast/labelStatement/statement/complicatedExampleFromJavaTutorial.kt

@@ -21,7 +21,7 @@ break@test
 }
 }
 }
-System.out.println((if (foundIt)
+System.`out`?.println((if (foundIt)
 "Found it"
 else
 "Didn't find it"))

testData/ast/parenthesizedExpression/expression/parenthesized2.jav

@@ -1 +1 @@
-(o.toString() + "abc")
+(str.toString() + "abc")

testData/ast/parenthesizedExpression/expression/parenthesized2.kt

@@ -1 +1 @@
-((o.toString() + "abc"))
+((str.toString() + "abc"))