A temporary fix for the whitespace problem (each marker is wrapped, this is costly)

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

@@ -0,0 +1,68 @@
+package org.jetbrains.jet.lang.parsing;
+
+import com.intellij.lang.PsiBuilder;
+import com.intellij.lang.WhitespacesAndCommentsBinder;
+import com.intellij.psi.tree.IElementType;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * @author abreslav
+ */
+public class MarkerAdapter implements PsiBuilder.Marker {
+
+    private final PsiBuilder.Marker delegate;
+
+    public MarkerAdapter(PsiBuilder.Marker delegate) {
+        this.delegate = delegate;
+    }
+
+    @Override
+    public PsiBuilder.Marker precede() {
+        return delegate.precede();
+    }
+
+    @Override
+    public void drop() {
+        delegate.drop();
+    }
+
+    @Override
+    public void rollbackTo() {
+        delegate.rollbackTo();
+    }
+
+    @Override
+    public void done(IElementType type) {
+        delegate.done(type);
+    }
+
+    @Override
+    public void collapse(IElementType type) {
+        delegate.collapse(type);
+    }
+
+    @Override
+    public void doneBefore(IElementType type, PsiBuilder.Marker before) {
+        delegate.doneBefore(type, before);
+    }
+
+    @Override
+    public void doneBefore(IElementType type, PsiBuilder.Marker before, String errorMessage) {
+        delegate.doneBefore(type, before, errorMessage);
+    }
+
+    @Override
+    public void error(String message) {
+        delegate.error(message);
+    }
+
+    @Override
+    public void errorBefore(String message, PsiBuilder.Marker before) {
+        delegate.errorBefore(message, before);
+    }
+
+    @Override
+    public void setCustomEdgeTokenBinders(@Nullable WhitespacesAndCommentsBinder left, @Nullable WhitespacesAndCommentsBinder right) {
+        delegate.setCustomEdgeTokenBinders(left, right);
+    }
+}

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

@@ -39,4 +39,18 @@ public class SemanticWhitespaceAwarePsiBuilderImpl extends PsiBuilderAdapter imp
     public boolean eolInLastWhitespace() {
         return myEOLInLastWhitespace || eof();
     }
+
+    // TODO: Overhead
+    @Override
+    public Marker mark() {
+        return new MarkerAdapter(super.mark()) {
+            private final boolean eolInLastWhitespace = eolInLastWhitespace();
+
+            @Override
+            public void rollbackTo() {
+                super.rollbackTo();
+                myEOLInLastWhitespace = eolInLastWhitespace;
+            }
+        };
+    }
 }