Predicate expression, a?b?.f()

grammar/src/expressions.grm

@@ -174,7 +174,7 @@ postfixUnaryOperation
   ;
 
 memberAccessOperation
-  : "." : "?." : "#"
+  : "." : "?." : "#" : "?"
   ;
 
 typeArguments

idea/src/org/jetbrains/jet/JetNodeTypes.java

@@ -105,6 +105,7 @@ public interface JetNodeTypes {
     JetNodeType DOT_QIALIFIED_EXPRESSION  = new JetNodeType("DOT_QIALIFIED_EXPRESSION", JetDotQualifiedExpression.class);
     JetNodeType HASH_QIALIFIED_EXPRESSION = new JetNodeType("HASH_QIALIFIED_EXPRESSION", JetHashQualifiedExpression.class);
     JetNodeType SAFE_ACCESS_EXPRESSION    = new JetNodeType("SAFE_ACCESS_EXPRESSION", JetSafeQualifiedExpression.class);
+    JetNodeType PREDICATE_EXPRESSION       = new JetNodeType("PREDICATE_EXPRESSION", JetPridcateExpression.class);
     JetNodeType DECOMPOSER_PATTERN        = new JetNodeType("DECOMPOSER_PATTERN");
     JetNodeType TUPLE_PATTERN             = new JetNodeType("TUPLE_PATTERN");
     JetNodeType OBJECT_LITERAL            = new JetNodeType("OBJECT_LITERAL", JetObjectLiteralExpression.class);

idea/src/org/jetbrains/jet/lang/parsing/JetExpressionParsing.java

@@ -274,7 +274,15 @@ public class JetExpressionParsing extends AbstractJetParsing {
     }
 
     /*
-     * expression operation?
+     * atomicExpression postfixUnaryOperation?
+     *
+     * postfixUnaryOperation
+     *   : "++" : "--"
+     *   : typeArguments? valueArguments
+     *   : typeArguments
+     *   : arrayAccess
+     *   : memberAccessOperation postfixUnaryOperation // TODO: Review
+     *   ;
      */
     private void parsePostfixExpression() {
 //        System.out.println("post at "  + myBuilder.getTokenText());
@@ -324,6 +332,12 @@ public class JetExpressionParsing extends AbstractJetParsing {
                 parseAtomicExpression();
 
                 expression.done(SAFE_ACCESS_EXPRESSION);
+            } else if (at(QUEST)) {
+                advance(); // QUEST
+
+                parseAtomicExpression();
+
+                expression.done(PREDICATE_EXPRESSION);
             } else if (at(HASH)) {
                 advance(); // HASH
 

idea/src/org/jetbrains/jet/lang/psi/JetPridcateExpression.java

@@ -0,0 +1,13 @@
+package org.jetbrains.jet.lang.psi;
+
+import com.intellij.lang.ASTNode;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * @author abreslav
+ */
+public class JetPridcateExpression extends JetQualifiedExpression {
+    public JetPridcateExpression(@NotNull ASTNode node) {
+        super(node);
+    }
+}

idea/testData/psi/PredicateExpression.jet

@@ -0,0 +1,3 @@
+fun foo() {
+  a?f.foo
+}

idea/testData/psi/PredicateExpression.txt

@@ -0,0 +1,27 @@
+JetFile: PredicateExpression.jet
+  NAMESPACE
+    FUN
+      PsiElement(fun)('fun')
+      PsiWhiteSpace(' ')
+      PsiElement(IDENTIFIER)('foo')
+      TYPE_PARAMETER_LIST
+        <empty list>
+      VALUE_PARAMETER_LIST
+        PsiElement(LPAR)('(')
+        PsiElement(RPAR)(')')
+      PsiWhiteSpace(' ')
+      BLOCK
+        PsiElement(LBRACE)('{')
+        PsiWhiteSpace('\n  ')
+        DOT_QIALIFIED_EXPRESSION
+          PREDICATE_EXPRESSION
+            REFERENCE_EXPRESSION
+              PsiElement(IDENTIFIER)('a')
+            PsiElement(QUEST)('?')
+            REFERENCE_EXPRESSION
+              PsiElement(IDENTIFIER)('f')
+          PsiElement(DOT)('.')
+          REFERENCE_EXPRESSION
+            PsiElement(IDENTIFIER)('foo')
+        PsiWhiteSpace('\n')
+        PsiElement(RBRACE)('}')