Merge lp:~zorba-coders/zorba/markos-scratch into lp:zorba

[Markos Zaharioudakis]

1. Better computation of the static type for global variables
2. Optimization of comparison operators when untypedAtomic items are involved.

1. Better computation of the static type for global variables
2. Optimization of comparison operators when untypedAtomic items are involved.

[lp:~zorba-coders/zorba/markos-scratch]

10995. By Markos Zaharioudakis on 2012-12-06

1. Better computation of the static type for global variables, 2. Optimization of comparison operators when untypedAtomic items are involved

[Markos Zaharioudakis (markos-za)]

review: Approve

[Zorba Build Bot (zorba-buildbot)]

Validation queue starting for merge proposal.
Log at: http://zorbatest.lambda.nu:8080/remotequeue/markos-scratch-2012-12-06T22-59-53.623Z/log.html

[Zorba Build Bot (zorba-buildbot)]

Validation queue job markos-scratch-2012-12-06T22-59-53.623Z is finished. The final status was:

All tests succeeded!

=== modified file 'ChangeLog'
--- ChangeLog	2012-11-29 19:17:08 +0000
+++ ChangeLog	2012-12-06 22:51:20 +0000
@@ -12,6 +12,8 @@
 
 Optimizations:
   * Various optimizations in the implementation of the optimizer rules.
+  * Better computation of the static type for global variables.
+  * Optimization of comparison operators when untypedAtomic items are involved.
 
 Bug Fixes/Other Changes:
   * Change XQXQ (XQuery-for-XQuery) module now part of Zorba core
@@ -28,9 +30,10 @@
   * Fixed bug #1065321 (following:text() doesn't return results in doc order)
   * Fixed bug #1067706 (wrong const folding in mutually recursive udfs)
   * Fixed bug #1021492 (while computeing the "sources" of a prolog var, skip
-    any var-setting exprs that appear in non-used (and non-optimized) functions). 
+    any var-setting exprs that appear in non-used (and non-optimized) functions).
   * Fixed bug #1070551 (zerr:ZOSE0003 stream read failure)
 
+
 version 2.7
 
 New Features:
 
=== modified file 'src/compiler/api/compiler_api.cpp'
--- src/compiler/api/compiler_api.cpp	2012-10-08 12:09:36 +0000
+++ src/compiler/api/compiler_api.cpp	2012-12-06 22:51:20 +0000
@@ -138,10 +138,10 @@
 #ifdef ZORBA_XQUERYX
   char* converted_xquery_str = NULL;
   std::string   xquery_str;
-  bool  is_xqueryx = false;
+  bool is_xqueryx = false;
+
   {
-    char  strtemp[1000];
-    //int   nr_read = 1;
+    char strtemp[1000];
     do
     {
       strtemp[0] = 0;
@@ -175,26 +175,30 @@
   {
     xquery_stream = new std::istringstream(xquery_str);
   }
-#endif
+#endif // ZORBA_XQUERYX
+
+  theCompilerCB->setPhase(CompilerCB::PARSING);
 
   xquery_driver lDriver(&*theCompilerCB);
   lDriver.parse_stream(*xquery_stream, aFileName);
 
+  theCompilerCB->setPhase(CompilerCB::NONE);
+
 #ifdef ZORBA_XQUERYX
   delete xquery_stream;
-  if(is_xqueryx)
+  if (is_xqueryx)
   {
     xqxconvertor->freeResult(converted_xquery_str);
   }
 #endif
+
   parsenode_t node = lDriver.get_expr();
 
   if (typeid (*node) == typeid (ParseErrorNode))
   {
     ParseErrorNode* pen = static_cast<ParseErrorNode *>(&*node);
-    throw XQUERY_EXCEPTION_VAR(
-      pen->err, ERROR_PARAMS(pen->msg), ERROR_LOC(pen->get_location())
-		);
+    throw XQUERY_EXCEPTION_VAR(pen->err, 
+    ERROR_PARAMS(pen->msg), ERROR_LOC(pen->get_location()));
   }
 
   return node;
@@ -285,7 +289,11 @@
                   audit::XQUERY_COMPILATION_CODEGENERATION_DURATION,
                   lTimer);
 
+    theCompilerCB->setPhase(CompilerCB::CODEGEN);
+
     plan = codegen("main query", rootExpr, theCompilerCB, nextDynamicVarId);
+
+    theCompilerCB->setPhase(CompilerCB::NONE);
   }
 
   //theCompilerCB->getExprManager()->garbageCollect();
@@ -306,8 +314,12 @@
   time::get_current_walltime(startTime);
 #endif
 
+  theCompilerCB->setPhase(CompilerCB::TRANSLATION);
+
   expr* lExpr = translate(*aParsenode, theCompilerCB);
 
+  theCompilerCB->setPhase(CompilerCB::NONE);
+
 #if 0
   std::cout << "Num exprs after translation = "
             << theCompilerCB->getExprManager()->numExprs()
@@ -321,7 +333,7 @@
   if ( lExpr == NULL )
   {
     // TODO: can this happen?
-    throw ZORBA_EXCEPTION( zerr::ZAPI0002_XQUERY_COMPILATION_FAILED );
+    throw ZORBA_EXCEPTION(zerr::ZAPI0002_XQUERY_COMPILATION_FAILED);
   }
 
   return lExpr;
@@ -333,6 +345,8 @@
 ********************************************************************************/
 expr* XQueryCompiler::optimize(expr* lExpr)
 {
+  theCompilerCB->setPhase(CompilerCB::OPTIMIZATION);
+
   // Build the call-graph among the udfs that are actually used in the query
   // program.
   UDFGraph udfGraph(lExpr);
@@ -343,7 +357,10 @@
   udfGraph.inferDeterminism();
 
   if (theCompilerCB->theConfig.opt_level <= CompilerCB::config::O0)
+  {
+    theCompilerCB->setPhase(CompilerCB::NONE);
     return lExpr;
+  }
 
   // Optimize the udfs.
   udfGraph.optimizeUDFs(theCompilerCB);
@@ -362,6 +379,8 @@
   if ( theCompilerCB->theConfig.optimize_cb != NULL )
     theCompilerCB->theConfig.optimize_cb(lExpr, "main query");
 
+  theCompilerCB->setPhase(CompilerCB::NONE);
+
   return lExpr;
 }
 
 
=== modified file 'src/compiler/api/compilercb.cpp'
--- src/compiler/api/compilercb.cpp	2012-10-24 11:32:56 +0000
+++ src/compiler/api/compilercb.cpp	2012-12-06 22:51:20 +0000
@@ -113,6 +113,7 @@
 #ifdef ZORBA_WITH_DEBUGGER
   theDebuggerCommons(0),
 #endif
+  thePhase(NONE),
   theHasEval(false),
   theIsEval(false),
   theIsLoadProlog(false),
@@ -141,6 +142,7 @@
 #ifdef ZORBA_WITH_DEBUGGER
   theDebuggerCommons(cb.theDebuggerCommons),
 #endif
+  thePhase(NONE),
   theHasEval(false),
   theIsEval(false),
   theIsLoadProlog(false),
@@ -167,6 +169,7 @@
 #ifdef ZORBA_WITH_DEBUGGER
   theDebuggerCommons(NULL),
 #endif
+  thePhase(RUNTIME),
   theHasEval(false),
   theIsEval(false),
   theNextVisitId(1),
 
=== modified file 'src/compiler/api/compilercb.h'
--- src/compiler/api/compilercb.h	2012-10-24 11:32:56 +0000
+++ src/compiler/api/compilercb.h	2012-12-06 22:51:20 +0000
@@ -132,7 +132,7 @@
   Pointer to the function to call to print the expr tree that results from
   translating the query AST.
 ********************************************************************************/
-class ZORBA_DLL_PUBLIC CompilerCB : public zorba::serialization::SerializeBaseClass
+class CompilerCB : public zorba::serialization::SerializeBaseClass
 {
 public:
   struct config : public zorba::serialization::SerializeBaseClass
@@ -168,8 +168,22 @@
     void serialize(::zorba::serialization::Archiver& ar);
   };
 
+  typedef enum
+  {
+    NONE,
+    PARSING,
+    TRANSLATION,
+    OPTIMIZATION,
+    CODEGEN,
+    RUNTIME
+  } ProcessingPhase;
+
   typedef std::map<csize, static_context_t> SctxMap;
 
+  typedef std::multimap<const expr*, pragma*>  PragmaMap;
+
+  typedef PragmaMap::const_iterator PragmaMapIter;
+
 public:
   XQueryDiagnostics       * theXQueryDiagnostics;
 
@@ -181,6 +195,8 @@
   DebuggerCommons         * theDebuggerCommons;
 #endif
 
+  ProcessingPhase           thePhase;
+
   bool                      theHasEval;
 
   bool                      theIsEval;
@@ -197,15 +213,13 @@
 
   uint32_t                  theTempIndexCounter;
 
-  ulong                     theNextVisitId;
+  uint8_t                   theNextVisitId;
 
   config                    theConfig;
 
   ExprManager       * const theEM;
 
-  typedef std::multimap<const expr*, pragma*>  PragmaMap;
-  typedef PragmaMap::const_iterator            PragmaMapIter;
-  PragmaMap                                    thePragmas;
+  PragmaMap                 thePragmas;
 
 public:
   SERIALIZABLE_CLASS(CompilerCB);
@@ -219,6 +233,10 @@
 
   ~CompilerCB();
 
+  ProcessingPhase getPhase() const { return thePhase; }
+
+  void setPhase(ProcessingPhase v) { thePhase = v; }
+
   bool isLoadPrologQuery() const { return theIsLoadProlog; }
 
   void setLoadPrologQuery() { theIsLoadProlog = true; }
@@ -240,12 +258,9 @@
   //
   void add_pragma(const expr* e, pragma* p);
 
-  void
-  lookup_pragmas(const expr* e, std::vector<pragma*>& pragmas) const;
-
-  bool
-  lookup_pragma(const expr* e, const zstring& localname, pragma*&) const;
-
+  void lookup_pragmas(const expr* e, std::vector<pragma*>& pragmas) const;
+
+  bool lookup_pragma(const expr* e, const zstring& localname, pragma*&) const;
 };
 
 
 
=== modified file 'src/compiler/expression/expr_base.cpp'
--- src/compiler/expression/expr_base.cpp	2012-10-31 08:02:16 +0000
+++ src/compiler/expression/expr_base.cpp	2012-12-06 22:51:20 +0000
@@ -128,7 +128,9 @@
   theCCB(NULL),
   theSctx(NULL),
   theUDF(NULL),
-  theFlags1(0)
+  theAnnotationFlags(0),
+  theBoolFlags(0),
+  theVisitId(0)
 {
 }
 
@@ -148,7 +150,8 @@
   theUDF(udf),
   theLoc(loc),
   theKind(k),
-  theFlags1(0),
+  theAnnotationFlags(0),
+  theBoolFlags(0),
   theVisitId(0)
 {
   theScriptingKind = UNKNOWN_SCRIPTING_KIND;
@@ -328,7 +331,7 @@
   if (getDereferencesNodes() != ANNOTATION_TRUE_FIXED)
     setDereferencesNodes(ANNOTATION_FALSE);
 
-  //theFlags1 = 0;
+  //theAnnotationFlags = 0;
   //setNonDiscardable(ANNOTATION_FALSE);
   //setUnfoldable(ANNOTATION_FALSE);
 
@@ -374,14 +377,14 @@
 ********************************************************************************/
 BoolAnnotationValue expr::getProducesSortedNodes() const
 {
-  return (BoolAnnotationValue)(theFlags1 & PRODUCES_SORTED_NODES_MASK);
+  return (BoolAnnotationValue)(theAnnotationFlags & PRODUCES_SORTED_NODES_MASK);
 }
 
 
 void expr::setProducesSortedNodes(BoolAnnotationValue v)
 {
-  theFlags1 &= ~PRODUCES_SORTED_NODES_MASK;
-  theFlags1 |= v;
+  theAnnotationFlags &= ~PRODUCES_SORTED_NODES_MASK;
+  theAnnotationFlags |= v;
 }
 
 
@@ -398,14 +401,14 @@
 BoolAnnotationValue expr::getProducesDistinctNodes() const
 {
   return (BoolAnnotationValue)
-         ((theFlags1 & PRODUCES_DISTINCT_NODES_MASK) >> PRODUCES_DISTINCT_NODES);
+         ((theAnnotationFlags & PRODUCES_DISTINCT_NODES_MASK) >> PRODUCES_DISTINCT_NODES);
 }
 
 
 void expr::setProducesDistinctNodes(BoolAnnotationValue v)
 {
-  theFlags1 &= ~PRODUCES_DISTINCT_NODES_MASK;
-  theFlags1 |= (v << PRODUCES_DISTINCT_NODES);
+  theAnnotationFlags &= ~PRODUCES_DISTINCT_NODES_MASK;
+  theAnnotationFlags |= (v << PRODUCES_DISTINCT_NODES);
 }
 
 
@@ -422,14 +425,14 @@
 BoolAnnotationValue expr::getIgnoresSortedNodes() const
 {
   return (BoolAnnotationValue)
-         ((theFlags1 & IGNORES_SORTED_NODES_MASK) >> IGNORES_SORTED_NODES);
+         ((theAnnotationFlags & IGNORES_SORTED_NODES_MASK) >> IGNORES_SORTED_NODES);
 }
 
 
 void expr::setIgnoresSortedNodes(BoolAnnotationValue v)
 {
-  theFlags1 &= ~IGNORES_SORTED_NODES_MASK;
-  theFlags1 |= (v << IGNORES_SORTED_NODES);
+  theAnnotationFlags &= ~IGNORES_SORTED_NODES_MASK;
+  theAnnotationFlags |= (v << IGNORES_SORTED_NODES);
 }
 
 
@@ -446,14 +449,14 @@
 BoolAnnotationValue expr::getIgnoresDuplicateNodes() const
 {
   return (BoolAnnotationValue)
-         ((theFlags1 & IGNORES_DUPLICATE_NODES_MASK) >> IGNORES_DUPLICATE_NODES);
+         ((theAnnotationFlags & IGNORES_DUPLICATE_NODES_MASK) >> IGNORES_DUPLICATE_NODES);
 }
 
 
 void expr::setIgnoresDuplicateNodes(BoolAnnotationValue v)
 {
-  theFlags1 &= ~IGNORES_DUPLICATE_NODES_MASK;
-  theFlags1 |= (v << IGNORES_DUPLICATE_NODES);
+  theAnnotationFlags &= ~IGNORES_DUPLICATE_NODES_MASK;
+  theAnnotationFlags |= (v << IGNORES_DUPLICATE_NODES);
 }
 
 
@@ -469,14 +472,14 @@
 BoolAnnotationValue expr::getNonDiscardable() const
 {
   return (BoolAnnotationValue)
-         ((theFlags1 & NON_DISCARDABLE_MASK) >> NON_DISCARDABLE);
+         ((theAnnotationFlags & NON_DISCARDABLE_MASK) >> NON_DISCARDABLE);
 }
 
 
 void expr::setNonDiscardable(BoolAnnotationValue v)
 {
-  theFlags1 &= ~NON_DISCARDABLE_MASK;
-  theFlags1 |= (v << NON_DISCARDABLE);
+  theAnnotationFlags &= ~NON_DISCARDABLE_MASK;
+  theAnnotationFlags |= (v << NON_DISCARDABLE);
 }
 
 
@@ -493,14 +496,14 @@
 BoolAnnotationValue expr::getUnfoldable() const
 {
   return (BoolAnnotationValue)
-         ((theFlags1 & UNFOLDABLE_MASK) >> UNFOLDABLE);
+         ((theAnnotationFlags & UNFOLDABLE_MASK) >> UNFOLDABLE);
 }
 
 
 void expr::setUnfoldable(BoolAnnotationValue v)
 {
-  theFlags1 &= ~UNFOLDABLE_MASK;
-  theFlags1 |= (v << UNFOLDABLE);
+  theAnnotationFlags &= ~UNFOLDABLE_MASK;
+  theAnnotationFlags |= (v << UNFOLDABLE);
 }
 
 
@@ -517,14 +520,14 @@
 BoolAnnotationValue expr::getContainsRecursiveCall() const
 {
   return (BoolAnnotationValue)
-         ((theFlags1 & CONTAINS_RECURSIVE_CALL_MASK) >> CONTAINS_RECURSIVE_CALL);
+         ((theAnnotationFlags & CONTAINS_RECURSIVE_CALL_MASK) >> CONTAINS_RECURSIVE_CALL);
 }
 
 
 void expr::setContainsRecursiveCall(BoolAnnotationValue v)
 {
-  theFlags1 &= ~CONTAINS_RECURSIVE_CALL_MASK;
-  theFlags1 |= (v << CONTAINS_RECURSIVE_CALL);
+  theAnnotationFlags &= ~CONTAINS_RECURSIVE_CALL_MASK;
+  theAnnotationFlags |= (v << CONTAINS_RECURSIVE_CALL);
 }
 
 
@@ -541,14 +544,14 @@
 BoolAnnotationValue expr::getContainsPragma() const
 {
   return (BoolAnnotationValue)
-         ((theFlags1 & CONTAINS_PRAGMA_MASK) >> CONTAINS_PRAGMA);
+         ((theAnnotationFlags & CONTAINS_PRAGMA_MASK) >> CONTAINS_PRAGMA);
 }
 
 
 void expr::setContainsPragma(BoolAnnotationValue v)
 {
-  theFlags1 &= ~CONTAINS_PRAGMA_MASK;
-  theFlags1 |= (v << CONTAINS_PRAGMA);
+  theAnnotationFlags &= ~CONTAINS_PRAGMA_MASK;
+  theAnnotationFlags |= (v << CONTAINS_PRAGMA);
 }
 
 
@@ -566,14 +569,14 @@
 BoolAnnotationValue expr::getConstructsNodes() const
 {
   return (BoolAnnotationValue)
-         ((theFlags1 & CONSTRUCTS_NODES_MASK) >> CONSTRUCTS_NODES);
+         ((theAnnotationFlags & CONSTRUCTS_NODES_MASK) >> CONSTRUCTS_NODES);
 }
 
 
 void expr::setConstructsNodes(BoolAnnotationValue v)
 {
-  theFlags1 &= ~CONSTRUCTS_NODES_MASK;
-  theFlags1 |= (v << CONSTRUCTS_NODES);
+  theAnnotationFlags &= ~CONSTRUCTS_NODES_MASK;
+  theAnnotationFlags |= (v << CONSTRUCTS_NODES);
 }
 
 
@@ -591,14 +594,14 @@
 BoolAnnotationValue expr::getDereferencesNodes() const
 {
   return (BoolAnnotationValue)
-         ((theFlags1 & DEREFERENCES_NODES_MASK) >> DEREFERENCES_NODES);
+         ((theAnnotationFlags & DEREFERENCES_NODES_MASK) >> DEREFERENCES_NODES);
 }
 
 
 void expr::setDereferencesNodes(BoolAnnotationValue v)
 {
-  theFlags1 &= ~DEREFERENCES_NODES_MASK;
-  theFlags1 |= (v << DEREFERENCES_NODES);
+  theAnnotationFlags &= ~DEREFERENCES_NODES_MASK;
+  theAnnotationFlags |= (v << DEREFERENCES_NODES);
 }
 
 
@@ -620,14 +623,14 @@
 BoolAnnotationValue expr::getMustCopyNodes() const
 {
   return (BoolAnnotationValue)
-         ((theFlags1 & MUST_COPY_NODES_MASK) >> MUST_COPY_NODES);
+         ((theAnnotationFlags & MUST_COPY_NODES_MASK) >> MUST_COPY_NODES);
 }
 
 
 void expr::setMustCopyNodes(BoolAnnotationValue v)
 {
-  theFlags1 &= ~MUST_COPY_NODES_MASK;
-  theFlags1 |= (v << MUST_COPY_NODES);
+  theAnnotationFlags &= ~MUST_COPY_NODES_MASK;
+  theAnnotationFlags |= (v << MUST_COPY_NODES);
 }
 
 
 
=== modified file 'src/compiler/expression/expr_base.h'
--- src/compiler/expression/expr_base.h	2012-10-26 07:13:42 +0000
+++ src/compiler/expression/expr_base.h	2012-12-06 22:51:20 +0000
@@ -169,6 +169,11 @@
     DEREFERENCES_NODES_MASK       = 0xC00000
   } AnnotationMask;
 
+  typedef enum
+  {
+    IN_TYPE_COMPUTE  = 0x1
+  } BoolFlags;
+
 
 protected:
   static expr*      iter_end_expr;
@@ -189,12 +194,14 @@
 
   xqtref_t           theType;
 
-  uint32_t           theFlags1;
+  uint32_t           theAnnotationFlags;
+
+  uint8_t            theBoolFlags;
+
+  uint8_t            theVisitId;
 
   FreeVars           theFreeVars;
 
-  int                theVisitId;
-
 public:
   static bool is_sequential(unsigned short theScriptingKind);
 
@@ -224,9 +231,9 @@
 
   void set_loc(const QueryLoc& loc) { theLoc = loc; }
 
-  uint32_t getFlags() const { return theFlags1; }
+  uint32_t getAnnotationFlags() const { return theAnnotationFlags; }
 
-  void setFlags(uint32_t flags) { theFlags1 = flags; }
+  void setAnnotationFlags(uint32_t flags) { theAnnotationFlags = flags; }
 
   unsigned short get_scripting_detail() const { return theScriptingKind; }
 
@@ -263,6 +270,20 @@
   std::string toString() const;
 
 public:
+  //
+  void setVisitId(uint8_t id) { theVisitId = id; }
+
+  bool isVisited(uint8_t id) const { return theVisitId == id; }
+
+  uint8_t getVisitId() const { return theVisitId; }
+
+  // Transient flag used only during the type computation for global vars
+  bool isInTypeCompute() const { return theBoolFlags & IN_TYPE_COMPUTE; }
+
+  void setInTypeCompute() { theBoolFlags |= IN_TYPE_COMPUTE; }
+
+  void resetInTypeCompute() { theBoolFlags &= ~IN_TYPE_COMPUTE; }
+
   // Annotation : produces-sorted-nodes
   BoolAnnotationValue getProducesSortedNodes() const;
 
@@ -351,12 +372,6 @@
   void setFreeVars(FreeVars& s);
 
   //
-  void setVisitId(int id) { theVisitId = id; }
-
-  bool isVisited(int id) const { return theVisitId == id; }
-
-  int getVisitId() const { return theVisitId; }
-
   bool is_constant() const;
 
   bool is_nondeterministic() const;
 
=== modified file 'src/compiler/expression/expr_clone.cpp'
--- src/compiler/expression/expr_clone.cpp	2012-10-24 11:32:56 +0000
+++ src/compiler/expression/expr_clone.cpp	2012-12-06 22:51:20 +0000
@@ -618,7 +618,7 @@
                          udf,
                          theLoc,
                          varCopy,
-                         (e->theInitExpr ? e->theInitExpr->clone(udf, subst) : NULL));
+                         (e->theExpr ? e->theExpr->clone(udf, subst) : NULL));
     
     break;
   }
 
=== modified file 'src/compiler/expression/expr_iter.cpp'
--- src/compiler/expression/expr_iter.cpp	2012-10-24 11:32:56 +0000
+++ src/compiler/expression/expr_iter.cpp	2012-12-06 22:51:20 +0000
@@ -825,8 +825,8 @@
 
     EXPR_ITER_BEGIN();
 
-    if (varDeclExpr->theInitExpr)
-      EXPR_ITER_NEXT(varDeclExpr->theInitExpr);
+    if (varDeclExpr->theExpr)
+      EXPR_ITER_NEXT(varDeclExpr->theExpr);
 
     EXPR_ITER_END();
     return;
 
=== modified file 'src/compiler/expression/expr_put.cpp'
--- src/compiler/expression/expr_put.cpp	2012-10-30 10:02:56 +0000
+++ src/compiler/expression/expr_put.cpp	2012-12-06 22:51:20 +0000
@@ -462,8 +462,8 @@
   BEGIN_PUT(var_decl_expr);
 
   theVarExpr->put(os);
-  if (theInitExpr)
-    theInitExpr->put(os);
+  if (theExpr)
+    theExpr->put(os);
 
   END_PUT();
 }
 
=== modified file 'src/compiler/expression/expr_type.cpp'
--- src/compiler/expression/expr_type.cpp	2012-10-31 08:02:16 +0000
+++ src/compiler/expression/expr_type.cpp	2012-12-06 22:51:20 +0000
@@ -31,6 +31,9 @@
 #include "compiler/expression/var_expr.h"
 #include "compiler/expression/expr.h"
 #include "compiler/expression/expr_iter.h"
+
+#include "compiler/api/compilercb.h"
+
 #include "compiler/xqddf/collection_decl.h"
 
 #include "functions/function.h"
@@ -118,9 +121,9 @@
 
     TypeConstants::quantifier_t quant = TypeConstants::QUANT_ONE;
 
-    ulong numClauses = e->num_clauses();
+    csize numClauses = e->num_clauses();
 
-    for (ulong i = 0; i < numClauses && quant != TypeConstants::QUANT_STAR; ++i)
+    for (csize i = 0; i < numClauses && quant != TypeConstants::QUANT_STAR; ++i)
     {
       const flwor_clause* c = e->theClauses[i];
 
@@ -213,8 +216,38 @@
     }
     case var_expr::prolog_var:
     {
-      // For const global vars, their type is set in 
+      // NOTE: For const global vars, their declared type is set to the
+      // type of their init expr, if any. This is done in 
       // translator::end_visit(const GlobalVarDecl& v, void*)
+
+      csize numSetExprs = e->num_set_exprs();
+
+      if (e->get_ccb()->getPhase() == CompilerCB::OPTIMIZATION &&
+          numSetExprs > 0 &&
+          !e->is_external() &&
+          !e->isInTypeCompute())
+      {
+        e->setInTypeCompute();
+
+        var_set_expr* setExpr = e->get_set_expr(0);
+
+        derivedType = setExpr->get_expr()->get_return_type();
+
+        for (csize i = 1; i < numSetExprs; ++i)
+        {
+          if (derivedType == rtm.ITEM_TYPE_STAR)
+            break;
+
+          setExpr = e->get_set_expr(i);
+
+          derivedType = TypeOps::union_type(*derivedType,
+                                            *setExpr->get_expr()->get_return_type(),
+                                            tm);
+        }
+
+        e->resetInTypeCompute();
+      }
+
       break;
     }
     case var_expr::local_var: // TODO: compute derived type for const local vars.
 
=== modified file 'src/compiler/expression/script_exprs.cpp'
--- src/compiler/expression/script_exprs.cpp	2012-10-24 11:32:56 +0000
+++ src/compiler/expression/script_exprs.cpp	2012-12-06 22:51:20 +0000
@@ -208,17 +208,11 @@
     var_expr* varExpr,
     expr* initExpr)
   :
-  expr(ccb, sctx, udf, loc, var_decl_expr_kind),
-  theVarExpr(varExpr),
-  theInitExpr(initExpr)
+  var_set_expr(ccb, sctx, udf, loc, varExpr, initExpr, true)
 {
+  theKind = var_decl_expr_kind;
+
   compute_scripting_kind();
-
-  // var_decl_expr is unfoldable because it requires access to the dyn ctx.
-  setUnfoldable(ANNOTATION_TRUE_FIXED);
-
-  if (initExpr)
-    varExpr->add_set_expr(this);
 }
 
 
@@ -234,17 +228,17 @@
 void var_decl_expr::compute_scripting_kind()
 {
   if (theVarExpr->get_kind() == var_expr::prolog_var)
-    checkSimpleExpr(theInitExpr);
+    checkSimpleExpr(theExpr);
   else
-    checkNonUpdating(theInitExpr);
+    checkNonUpdating(theExpr);
 
-  if (theInitExpr == NULL)
+  if (theExpr == NULL)
   {
     theScriptingKind = SIMPLE_EXPR;
   }
   else
   {
-    theScriptingKind = theInitExpr->get_scripting_detail();
+    theScriptingKind = theExpr->get_scripting_detail();
   }
 }
 
@@ -258,7 +252,8 @@
     user_function* udf,
     const QueryLoc& loc,
     var_expr* varExpr,
-    expr* setExpr)
+    expr* setExpr,
+    bool isDecl)
   :
   expr(ccb, sctx, udf, loc, var_set_expr_kind),
   theVarExpr(varExpr),
@@ -267,12 +262,15 @@
   assert(varExpr->get_kind() == var_expr::prolog_var ||
          varExpr->get_kind() == var_expr::local_var);
 
-  compute_scripting_kind();
+  if (!isDecl)
+    compute_scripting_kind();
 
-  // var_set_expr is unfoldable because it requires access to the dyn ctx.
+  // var_set_expr and var_decl_expr are unfoldable because they require access
+  // to the dyn ctx.
   setUnfoldable(ANNOTATION_TRUE_FIXED);
 
-  varExpr->add_set_expr(this);
+  if (setExpr)
+    varExpr->add_set_expr(this);
 }
 
 
 
=== modified file 'src/compiler/expression/script_exprs.h'
--- src/compiler/expression/script_exprs.h	2012-10-24 11:32:56 +0000
+++ src/compiler/expression/script_exprs.h	2012-12-06 22:51:20 +0000
@@ -181,6 +181,52 @@
 
 /*******************************************************************************
 
+  AssignStatement ::= "$" VarName ":=" ExprSingle ";"
+
+  The RHS of the assignment must be a non-updating expr.
+
+  var_set_expr is used to assign a value to a prolog or block-local var. During
+  runtime, the function computes theExpr and stores the resulting value inside
+  the appropriate dynamic ctx (global or local), at the location that is identified
+  by the variable id.
+********************************************************************************/
+class var_set_expr : public expr
+{
+  friend class ExprManager;
+  friend class ExprIterator;
+  friend class expr;
+
+protected:
+  var_expr * theVarExpr;
+  expr     * theExpr;
+
+protected:
+  var_set_expr(
+      CompilerCB* ccb,
+      static_context* sctx,
+      user_function* udf,
+      const QueryLoc& loc,
+      var_expr* varExpr,
+      expr* setExpr,
+      bool isDecl = false);
+
+public:
+  ~var_set_expr();
+
+  var_expr* get_var_expr() const { return theVarExpr; }
+
+  expr* get_expr() const { return theExpr; }
+
+  void compute_scripting_kind();
+
+  void accept(expr_visitor&);
+
+  std::ostream& put(std::ostream&) const;
+};
+
+
+/*******************************************************************************
+
   For Global Var:
   ----------------
 
@@ -207,17 +253,13 @@
   Note: the init expr must be non-updating. For global vars, it must also be
   non-sequential.
 ********************************************************************************/
-class var_decl_expr : public expr
+class var_decl_expr : public var_set_expr
 {
   friend class ExprManager;
   friend class ExprIterator;
   friend class expr;
 
 protected:
-  var_expr * theVarExpr;
-  expr     * theInitExpr;
-
-protected:
   var_decl_expr(
       CompilerCB* ccb,
       static_context* sctx,
@@ -229,54 +271,7 @@
 public:
   ~var_decl_expr();
 
-  var_expr* get_var_expr() const { return theVarExpr; }
-
-  expr* get_init_expr() const { return theInitExpr; }
-
-  void compute_scripting_kind();
-
-  void accept(expr_visitor&);
-
-  std::ostream& put(std::ostream&) const;
-};
-
-
-/*******************************************************************************
-
-  AssignStatement ::= "$" VarName ":=" ExprSingle ";"
-
-  The RHS of the assignment must be a non-updating expr.
-
-  var_set_expr is used to assign a value to a prolog or block-local var. During
-  runtime, the function computes theExpr and stores the resulting value inside
-  the appropriate dynamic ctx (global or local), at the location that is identified
-  by the variable id.
-********************************************************************************/
-class var_set_expr : public expr
-{
-  friend class ExprManager;
-  friend class ExprIterator;
-  friend class expr;
-
-protected:
-  var_expr * theVarExpr;
-  expr     * theExpr;
-
-protected:
-  var_set_expr(
-      CompilerCB* ccb,
-      static_context* sctx,
-      user_function* udf,
-      const QueryLoc& loc,
-      var_expr* varExpr,
-      expr* setExpr);
-
-public:
-  ~var_set_expr();
-
-  var_expr* get_var_expr() const { return theVarExpr; }
-
-  expr* get_expr() const { return theExpr; }
+  expr* get_init_expr() const { return theExpr; }
 
   void compute_scripting_kind();
 
 
=== modified file 'src/compiler/expression/var_expr.cpp'
--- src/compiler/expression/var_expr.cpp	2012-10-31 08:02:16 +0000
+++ src/compiler/expression/var_expr.cpp	2012-12-06 22:51:20 +0000
@@ -18,6 +18,7 @@
 #include "functions/udf.h"
 
 #include "compiler/expression/var_expr.h"
+#include "compiler/expression/script_exprs.h"
 #include "compiler/expression/update_exprs.h"
 #include "compiler/expression/flwor_expr.h"
 #include "compiler/expression/expr_visitor.h"
@@ -300,13 +301,25 @@
 /*******************************************************************************
 
 ********************************************************************************/
+void var_expr::add_set_expr(expr* e)
+{
+  assert(e->get_expr_kind() == var_decl_expr_kind ||
+         e->get_expr_kind() == var_set_expr_kind);
+
+  theSetExprs.push_back(static_cast<var_set_expr*>(e));
+}
+
+
+/*******************************************************************************
+
+********************************************************************************/
 void var_expr::remove_set_expr(expr* e)
 {
   assert(theVarKind == local_var || theVarKind == prolog_var);
 
   bool found = false;
-  std::vector<expr*>::iterator ite = theSetExprs.begin();
-  std::vector<expr*>::iterator end = theSetExprs.end();
+  VarSetExprs::iterator ite = theSetExprs.begin();
+  VarSetExprs::iterator end = theSetExprs.end();
   for (; ite != end; ++ite)
   {
     if (*ite == e)
 
=== modified file 'src/compiler/expression/var_expr.h'
--- src/compiler/expression/var_expr.h	2012-10-26 07:13:42 +0000
+++ src/compiler/expression/var_expr.h	2012-12-06 22:51:20 +0000
@@ -28,6 +28,8 @@
 class copy_clause;
 class var_expr;
 class VarInfo;
+class var_set_expr;
+
 
 /******************************************************************************
 
@@ -116,6 +118,8 @@
   friend class ExprManager;
 
 public:
+  typedef std::vector<var_set_expr*> VarSetExprs;
+
   enum var_kind
   {
     unknown_var = 0,
@@ -161,7 +165,7 @@
 
   csize                 theParamPos;
 
-  std::vector<expr*>    theSetExprs;
+  VarSetExprs           theSetExprs;
 
   VarInfo             * theVarInfo;
 
@@ -244,17 +248,17 @@
 
   void set_param_pos(csize pos) { theParamPos = pos; }
 
-  void add_set_expr(expr* e) { theSetExprs.push_back(e); }
+  void add_set_expr(expr* e);
 
   void remove_set_expr(expr* e);
 
   csize num_set_exprs() const { return theSetExprs.size(); }
 
-  expr* get_set_expr(csize i) const { return theSetExprs[i]; }
-
-  std::vector<expr*>::const_iterator setExprsBegin() const { return theSetExprs.begin(); }
-
-  std::vector<expr*>::const_iterator setExprsEnd() const { return theSetExprs.end(); }
+  var_set_expr* get_set_expr(csize i) const { return theSetExprs[i]; }
+
+  VarSetExprs::const_iterator setExprsBegin() const { return theSetExprs.begin(); }
+
+  VarSetExprs::const_iterator setExprsEnd() const { return theSetExprs.end(); }
 
   bool is_context_item() const;
 
 
=== modified file 'src/compiler/rewriter/rules/hoist_rules.cpp'
--- src/compiler/rewriter/rules/hoist_rules.cpp	2012-10-29 11:41:36 +0000
+++ src/compiler/rewriter/rules/hoist_rules.cpp	2012-12-06 22:51:20 +0000
@@ -484,7 +484,7 @@
   expr* hoisted = rCtx.theEM->
   create_fo_expr(sctx, udf, loc, BUILTIN_FUNC(OP_HOIST_1), e);
 
-  hoisted->setFlags(e->getFlags());
+  hoisted->setAnnotationFlags(e->getAnnotationFlags());
   //letvar->setFlags(e->getFlags());
 
   let_clause* flref(rCtx.theEM->create_let_clause(sctx, loc, letvar, hoisted));
@@ -523,7 +523,7 @@
                  loc,
                  BUILTIN_FUNC(OP_UNHOIST_1),
                  rCtx.theEM->create_wrapper_expr(sctx, udf, loc, letvar));
-  unhoisted->setFlags(e->getFlags());
+  unhoisted->setAnnotationFlags(e->getAnnotationFlags());
 
   return unhoisted;
 }
 
=== modified file 'src/compiler/rewriter/rules/index_join_rule.cpp'
--- src/compiler/rewriter/rules/index_join_rule.cpp	2012-11-02 20:00:13 +0000
+++ src/compiler/rewriter/rules/index_join_rule.cpp	2012-12-06 22:51:20 +0000
@@ -309,7 +309,7 @@
   {
     // Normally, other rewrite rules should have added the necessary casting
     // to the eq operands so that their static types have quantifiers ONE
-    // or QUESTION and the associated prime types are not xs:untypedAtomic.
+    // or QUESTION and the associated prime types are not xs:anyAtomicType.
     // But just in case those rules have been disabled, we check again here
     // and reject the hashjoin rewrite if these condition are violated.
 
@@ -323,10 +323,11 @@
 
     // The type of the outer/inner operands in the join predicate must not be
     // xs:untypedAtomic or xs:anyAtomic.
+    /*
     if (TypeOps::is_equal(tm, *primeOuterType, *rtm.UNTYPED_ATOMIC_TYPE_ONE, outerLoc) ||
         TypeOps::is_equal(tm, *primeInnerType, *rtm.UNTYPED_ATOMIC_TYPE_ONE, innerLoc))
       return false;
-
+    */
     if (TypeOps::is_equal(tm, *primeOuterType, *rtm.ANY_ATOMIC_TYPE_ONE, outerLoc) ||
         TypeOps::is_equal(tm, *primeInnerType, *rtm.ANY_ATOMIC_TYPE_ONE, innerLoc))
       return false;
 
=== modified file 'src/compiler/rewriter/rules/nodeid_rules.cpp'
--- src/compiler/rewriter/rules/nodeid_rules.cpp	2012-10-31 08:02:16 +0000
+++ src/compiler/rewriter/rules/nodeid_rules.cpp	2012-12-06 22:51:20 +0000
@@ -1161,24 +1161,12 @@
       {
         e->setVisitId(1);
 
-        std::vector<expr*>::const_iterator ite = e->setExprsBegin();
-        std::vector<expr*>::const_iterator end = e->setExprsEnd();
+        var_expr::VarSetExprs::const_iterator ite = e->setExprsBegin();
+        var_expr::VarSetExprs::const_iterator end = e->setExprsEnd();
 
         for (; ite != end; ++ite)
         {
-          expr* setExpr = *ite;
-          expr* valueExpr;
-
-          if (setExpr->get_expr_kind() == var_decl_expr_kind)
-          {
-            valueExpr = static_cast<var_decl_expr*>(setExpr)->get_init_expr();
-          }
-          else
-          {
-            assert(setExpr->get_expr_kind() == var_set_expr_kind);
-
-            valueExpr = static_cast<var_set_expr*>(setExpr)->get_expr();
-          }
+          expr* valueExpr = (*ite)->get_expr();
 
           findSourcesForNodeExtractors(valueExpr);
         }
 
=== modified file 'src/compiler/rewriter/rules/type_rules.cpp'
--- src/compiler/rewriter/rules/type_rules.cpp	2012-10-31 08:02:16 +0000
+++ src/compiler/rewriter/rules/type_rules.cpp	2012-12-06 22:51:20 +0000
@@ -235,12 +235,10 @@
 
 RULE_REWRITE_POST(SpecializeOperations)
 {
-  const Properties& props = *Properties::instance();
-
   RootTypeManager& rtm = GENV_TYPESYSTEM;
   TypeManager* tm = node->get_type_manager();
-
   static_context* sctx = node->get_sctx();
+  user_function* udf = node->get_udf();
 
   if (node->get_expr_kind() == fo_expr_kind)
   {
@@ -255,7 +253,9 @@
         fnKind == FunctionConsts::FN_SUM_2)
     {
       expr* argExpr = fo->get_arg(0);
+      const QueryLoc& argLoc = argExpr->get_loc();
       xqtref_t argType = argExpr->get_return_type();
+   
       std::vector<xqtref_t> argTypes;
       argTypes.push_back(argType);
 
@@ -264,14 +264,11 @@
       {
         fo->set_func(replacement);
 
-        if (TypeOps::is_subtype(tm,
-                                *argType,
-                                *rtm.UNTYPED_ATOMIC_TYPE_STAR,
-                                argExpr->get_loc()))
+        if (TypeOps::is_subtype(tm, *argType, *rtm.UNTYPED_ATOMIC_TYPE_STAR, argLoc))
         {
           expr* promoteExpr = rCtx.theEM->
-          create_promote_expr(argExpr->get_sctx(),
-                              argExpr->get_udf(),
+          create_promote_expr(sctx,
+                              udf,
                               argExpr->get_loc(),
                               argExpr,
                               rtm.DOUBLE_TYPE_STAR,
@@ -359,7 +356,7 @@
       if (t0->max_card() > 1 || t1->max_card() > 1)
         return NULL;
 
-      if (props.specializeNum() && fn->isArithmeticFunction())
+      if (fn->isArithmeticFunction())
       {
         if (! TypeOps::is_numeric_or_untyped(tm, *t0) ||
             ! TypeOps::is_numeric_or_untyped(tm, *t1))
@@ -368,13 +365,38 @@
         if (specialize_numeric(fo, sctx, rCtx) != NULL)
           return node;
       }
-      else if (props.specializeCmp() && fn->isComparisonFunction())
-      {
-        if (fn->isGeneralComparisonFunction())
+      else if (fn->isGeneralComparisonFunction())
+      {
+        std::vector<xqtref_t> argTypes;
+        argTypes.push_back(t0);
+        argTypes.push_back(t1);
+        function* replacement = fn->specialize(sctx, argTypes);
+        if (replacement != NULL)
+        {
+          fo->set_func(replacement);
+          return node;
+        }
+      }
+      else if (fn->isValueComparisonFunction())
+      {
+        xqtref_t stringType = rtm.STRING_TYPE_QUESTION;
+        xqtref_t untypedType = rtm.UNTYPED_ATOMIC_TYPE_QUESTION;
+
+        const QueryLoc& loc0 = arg0->get_loc();
+        const QueryLoc& loc1 = arg1->get_loc();
+
+        bool atomicORstring0 = (TypeOps::is_subtype(tm, *t0, *untypedType, loc0) ||
+                                TypeOps::is_subtype(tm, *t0, *stringType, loc0));
+
+        bool atomicORstring1 = (TypeOps::is_subtype(tm, *t1, *untypedType, loc1) ||
+                                TypeOps::is_subtype(tm, *t1, *stringType, loc1));
+
+        if (atomicORstring0 && atomicORstring1)
         {
           std::vector<xqtref_t> argTypes;
-          argTypes.push_back(t0);
-          argTypes.push_back(t1);
+          argTypes.push_back(stringType);
+          argTypes.push_back(stringType);
+          
           function* replacement = fn->specialize(sctx, argTypes);
           if (replacement != NULL)
           {
@@ -382,72 +404,24 @@
             return node;
           }
         }
-        else if (fn->isValueComparisonFunction())
+        else if (TypeOps::is_numeric(tm, *t0) && TypeOps::is_numeric(tm, *t1))
         {
-          xqtref_t string_type = rtm.STRING_TYPE_QUESTION;
-          bool string_cmp = true;
-          expr* nargs[2];
-
-          for (int i = 0; i < 2; ++i)
-          {
-            nargs[i] = NULL;
-
-            expr* arg = (i == 0 ? arg0 : arg1);
-            xqtref_t type = (i == 0 ? t0 : t1);
-            const QueryLoc& loc = arg->get_loc();
-
-            if (TypeOps::is_subtype(tm, *type, *rtm.UNTYPED_ATOMIC_TYPE_QUESTION, loc))
-            {
-              nargs[i] = rCtx.theEM->create_cast_expr(arg->get_sctx(),
-                                                      arg->get_udf(),
-                                                      arg->get_loc(),
-                                                      arg,
-                                                      string_type);
-            }
-            else if (! TypeOps::is_subtype(tm, *type, *string_type, loc))
-            {
-              string_cmp = false;
-              break;
-            }
-          }
-
-          if (string_cmp)
-          {
-            for (int i = 0; i < 2; i++)
-            {
-              if (nargs[i] != NULL)
-                fo->set_arg(i, nargs[i]);
-            }
-
-            std::vector<xqtref_t> argTypes;
-            argTypes.push_back(string_type);
-            argTypes.push_back(string_type);
-            function* replacement = fn->specialize(sctx, argTypes);
-            if (replacement != NULL)
-            {
-              fo->set_func(replacement);
-              return node;
-            }
-          }
-          else if (TypeOps::is_numeric(tm, *t0) && TypeOps::is_numeric(tm, *t1))
-          {
-            xqtref_t aType = specialize_numeric(fo, sctx, rCtx);
-            if (aType != NULL)
-            {
-              if (TypeOps::is_equal(tm,
-                                    *TypeOps::prime_type(tm, *aType),
-                                    *rtm.DECIMAL_TYPE_ONE,
-                                    fo->get_loc()) &&
-                  TypeOps::is_subtype(tm, *t0, *rtm.INTEGER_TYPE_ONE, fo->get_loc()))
-              {
-                expr* tmp = fo->get_arg(0);
-                fo->set_arg(0, fo->get_arg(1));
-                fo->set_arg(1, tmp);
-                fo->set_func(flip_value_cmp(fo->get_func()->getKind()));
-              }
-
-              return node;
-            }
+          xqtref_t aType = specialize_numeric(fo, sctx, rCtx);
+          if (aType != NULL)
+          {
+            if (TypeOps::is_equal(tm,
+                                  *TypeOps::prime_type(tm, *aType),
+                                  *rtm.DECIMAL_TYPE_ONE,
+                                  fo->get_loc()) &&
+                TypeOps::is_subtype(tm, *t0, *rtm.INTEGER_TYPE_ONE, fo->get_loc()))
+            {
+              expr* tmp = fo->get_arg(0);
+              fo->set_arg(0, fo->get_arg(1));
+              fo->set_arg(1, tmp);
+              fo->set_func(flip_value_cmp(fo->get_func()->getKind()));
+            }
+            
+            return node;
           }
         }
       }
@@ -456,7 +430,7 @@
   else if (node->get_expr_kind() == flwor_expr_kind ||
            node->get_expr_kind() == gflwor_expr_kind)
   {
-    flwor_expr* flworExpr = reinterpret_cast<flwor_expr*>(node);
+    flwor_expr* flworExpr = static_cast<flwor_expr*>(node);
 
     bool modified = false;
 
@@ -465,8 +439,8 @@
     {
       if (flworExpr->get_clause(i)->get_kind() == flwor_clause::order_clause)
       {
-        orderby_clause* obc = reinterpret_cast<orderby_clause*>
-                              (flworExpr->get_clause(i));
+        orderby_clause* obc =
+        static_cast<orderby_clause*>(flworExpr->get_clause(i));
 
         csize numColumns = obc->num_columns();
         for (csize j = 0; j < numColumns; ++j)
@@ -479,11 +453,7 @@
               TypeOps::is_subtype(tm, *colType, *rtm.UNTYPED_ATOMIC_TYPE_STAR, colLoc))
           {
             expr* castExpr = rCtx.theEM->
-            create_cast_expr(colExpr->get_sctx(),
-                             colExpr->get_udf(),
-                             colExpr->get_loc(),
-                             colExpr,
-                             rtm.STRING_TYPE_QUESTION);
+            create_cast_expr(sctx, udf, colLoc, colExpr, rtm.STRING_TYPE_QUESTION);
 
             obc->set_column_expr(j, castExpr);
             modified = true;
 
=== modified file 'src/compiler/rewriter/tools/dataflow_annotations.cpp'
--- src/compiler/rewriter/tools/dataflow_annotations.cpp	2012-11-02 20:00:13 +0000
+++ src/compiler/rewriter/tools/dataflow_annotations.cpp	2012-12-06 22:51:20 +0000
@@ -880,30 +880,17 @@
         varSources = new std::vector<expr*>;;
         theVarSourcesMap.insert(VarSourcesPair(e, varSources));
 
-        std::vector<expr*>::const_iterator ite2 = e->setExprsBegin();
-        std::vector<expr*>::const_iterator end2 = e->setExprsEnd();
+        var_expr::VarSetExprs::const_iterator ite2 = e->setExprsBegin();
+        var_expr::VarSetExprs::const_iterator end2 = e->setExprsEnd();
 
         for (; ite2 != end2; ++ite2)
         {
-          expr* setExpr = *ite2;
+          var_set_expr* setExpr = *ite2;
 
           if (setExpr->get_udf() != NULL && !setExpr->get_udf()->isOptimized())
             continue;
 
-          if (setExpr->get_expr_kind() == var_decl_expr_kind)
-          {
-            findNodeSourcesRec(static_cast<var_decl_expr*>(setExpr)->get_init_expr(),
-                               *varSources,
-                               currentUdf);
-          }
-          else
-          {
-            assert(setExpr->get_expr_kind() == var_set_expr_kind);
-
-            findNodeSourcesRec(static_cast<var_set_expr*>(setExpr)->get_expr(),
-                               *varSources,
-                               currentUdf);
-          }
+          findNodeSourcesRec(setExpr->get_expr(), *varSources, currentUdf);
         }
       }
       else
@@ -1323,25 +1310,14 @@
         varSources = new std::vector<expr*>;;
         theVarSourcesMap.insert(VarSourcesPair(e, varSources));
 
-        std::vector<expr*>::const_iterator ite2 = e->setExprsBegin();
-        std::vector<expr*>::const_iterator end2 = e->setExprsEnd();
+        var_expr::VarSetExprs::const_iterator ite2 = e->setExprsBegin();
+        var_expr::VarSetExprs::const_iterator end2 = e->setExprsEnd();
 
         for (; ite2 != end2; ++ite2)
         {
-          expr* setExpr = *ite2;
-
-          if (setExpr->get_expr_kind() == var_decl_expr_kind)
-          {
-            findLocalNodeSources(static_cast<var_decl_expr*>(setExpr)->get_init_expr(),
-                                 *varSources);
-          }
-          else
-          {
-            assert(setExpr->get_expr_kind() == var_set_expr_kind);
-
-            findLocalNodeSources(static_cast<var_set_expr*>(setExpr)->get_expr(),
-                                 *varSources);
-          }
+          var_set_expr* setExpr = *ite2;
+
+          findLocalNodeSources(setExpr->get_expr(), *varSources);
         }
       }
       else
 
=== modified file 'test/parser/CMakeLists.txt'
--- test/parser/CMakeLists.txt	2012-09-19 21:16:15 +0000
+++ test/parser/CMakeLists.txt	2012-12-06 22:51:20 +0000
@@ -15,12 +15,12 @@
 CONFIGURE_FILE(parsertestdriverconfig.h.in ${CMAKE_CURRENT_BINARY_DIR}/parsertestdriverconfig.h)
 INCLUDE_DIRECTORIES(${CMAKE_CURRENT_BINARY_DIR})
 
-ZORBA_GENERATE_EXE("parsertestdriver" "parsertestdriver.cpp" "" "" "")
+#ZORBA_GENERATE_EXE("parsertestdriver" "parsertestdriver.cpp" "" "" "")
 
 # collect all queries (suffix .xq) in all subdirectories of the Queries dir
-FILE(GLOB_RECURSE TESTFILES RELATIVE ${CMAKE_CURRENT_SOURCE_DIR}/Queries/ *.xq)
+#FILE(GLOB_RECURSE TESTFILES RELATIVE ${CMAKE_CURRENT_SOURCE_DIR}/Queries/ *.xq)
 
-MESSAGE(STATUS "Adding parser tests for CTest")
+#MESSAGE(STATUS "Adding parser tests for CTest")
 
 FOREACH(TESTFILE ${TESTFILES})
   STRING(LENGTH ${TESTFILE} TESTFILELENGTH)
 
=== modified file 'test/rbkt/ExpCompilerResults/IterPlan/zorba/collections/count_dynamic_zorba_collection.iter'
--- test/rbkt/ExpCompilerResults/IterPlan/zorba/collections/count_dynamic_zorba_collection.iter	2012-10-08 12:09:36 +0000
+++ test/rbkt/ExpCompilerResults/IterPlan/zorba/collections/count_dynamic_zorba_collection.iter	2012-12-06 22:51:20 +0000
@@ -6,19 +6,11 @@
   <SequentialIterator>
     <ApplyIterator>
       <ZorbaCreateCollectionIterator>
-        <PromoteIterator type="xs:QName">
-          <FnDataIterator>
-            <CtxVarIterator varid="4" varname="coll" varkind="global"/>
-          </FnDataIterator>
-        </PromoteIterator>
+        <CtxVarIterator varid="4" varname="coll" varkind="global"/>
       </ZorbaCreateCollectionIterator>
     </ApplyIterator>
     <CountCollectionIterator>
-      <PromoteIterator type="xs:QName">
-        <FnDataIterator>
-          <CtxVarIterator varid="4" varname="coll" varkind="global"/>
-        </FnDataIterator>
-      </PromoteIterator>
+      <CtxVarIterator varid="4" varname="coll" varkind="global"/>
     </CountCollectionIterator>
   </SequentialIterator>
 </SequentialIterator>
 
=== modified file 'test/rbkt/ExpCompilerResults/IterPlan/zorba/collections/count_static_zorba_collection.iter'
--- test/rbkt/ExpCompilerResults/IterPlan/zorba/collections/count_static_zorba_collection.iter	2012-10-08 12:09:36 +0000
+++ test/rbkt/ExpCompilerResults/IterPlan/zorba/collections/count_static_zorba_collection.iter	2012-12-06 22:51:20 +0000
@@ -24,19 +24,11 @@
   <SequentialIterator>
     <ApplyIterator>
       <ZorbaCreateCollectionIterator>
-        <PromoteIterator type="xs:QName">
-          <FnDataIterator>
-            <CtxVarIterator varid="10" varname="coll" varkind="global"/>
-          </FnDataIterator>
-        </PromoteIterator>
+        <CtxVarIterator varid="10" varname="coll" varkind="global"/>
       </ZorbaCreateCollectionIterator>
     </ApplyIterator>
     <CountCollectionIterator>
-      <PromoteIterator type="xs:QName">
-        <FnDataIterator>
-          <CtxVarIterator varid="10" varname="coll" varkind="global"/>
-        </FnDataIterator>
-      </PromoteIterator>
+      <CtxVarIterator varid="10" varname="coll" varkind="global"/>
     </CountCollectionIterator>
   </SequentialIterator>
 </SequentialIterator>
 
=== modified file 'test/rbkt/ExpCompilerResults/IterPlan/zorba/collections/count_w3c_collection.iter'
--- test/rbkt/ExpCompilerResults/IterPlan/zorba/collections/count_w3c_collection.iter	2012-10-08 12:09:36 +0000
+++ test/rbkt/ExpCompilerResults/IterPlan/zorba/collections/count_w3c_collection.iter	2012-12-06 22:51:20 +0000
@@ -6,19 +6,11 @@
   <SequentialIterator>
     <ApplyIterator>
       <UDFunctionCallIterator>
-        <PromoteIterator type="xs:string">
-          <FnDataIterator>
-            <CtxVarIterator varid="4" varname="coll" varkind="global"/>
-          </FnDataIterator>
-        </PromoteIterator>
+        <CtxVarIterator varid="4" varname="coll" varkind="global"/>
       </UDFunctionCallIterator>
     </ApplyIterator>
     <CountCollectionIterator>
-      <PromoteIterator type="xs:string">
-        <FnDataIterator>
-          <CtxVarIterator varid="4" varname="coll" varkind="global"/>
-        </FnDataIterator>
-      </PromoteIterator>
+      <CtxVarIterator varid="4" varname="coll" varkind="global"/>
     </CountCollectionIterator>
   </SequentialIterator>
 </SequentialIterator>
 
=== modified file 'test/rbkt/ExpCompilerResults/IterPlan/zorba/hashjoins/idx1.iter'
--- test/rbkt/ExpCompilerResults/IterPlan/zorba/hashjoins/idx1.iter	2012-09-19 21:16:15 +0000
+++ test/rbkt/ExpCompilerResults/IterPlan/zorba/hashjoins/idx1.iter	2012-12-06 22:51:20 +0000
@@ -28,17 +28,15 @@
           <ReturnClause>
             <ValueIndexEntryBuilderIterator>
               <ForVarIterator varname="$$opt_temp_3"/>
-              <CastIterator type="xs:string">
-                <PromoteIterator type="xs:anyAtomicType">
-                  <FnDataIterator>
-                    <AttributeAxisIterator test kind="match_name_test" qname="xs:QName(,,person)" typename="*" nill allowed="0">
-                      <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,buyer)" typename="*" nill allowed="0">
-                        <ForVarIterator varname="$$opt_temp_3"/>
-                      </ChildAxisIterator>
-                    </AttributeAxisIterator>
-                  </FnDataIterator>
-                </PromoteIterator>
-              </CastIterator>
+              <PromoteIterator type="xs:anyAtomicType">
+                <FnDataIterator>
+                  <AttributeAxisIterator test kind="match_name_test" qname="xs:QName(,,person)" typename="*" nill allowed="0">
+                    <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,buyer)" typename="*" nill allowed="0">
+                      <ForVarIterator varname="$$opt_temp_3"/>
+                    </ChildAxisIterator>
+                  </AttributeAxisIterator>
+                </FnDataIterator>
+              </PromoteIterator>
             </ValueIndexEntryBuilderIterator>
           </ReturnClause>
         </flwor::FLWORIterator>
@@ -66,13 +64,11 @@
         </LetVariable>
         <LetVariable name="$$opt_temp_1" materialize="true">
           <HoistIterator>
-            <CastIterator type="xs:string">
-              <FnDataIterator>
-                <AttributeAxisIterator test kind="match_name_test" qname="xs:QName(,,id)" typename="*" nill allowed="0">
-                  <ForVarIterator varname="p"/>
-                </AttributeAxisIterator>
-              </FnDataIterator>
-            </CastIterator>
+            <FnDataIterator>
+              <AttributeAxisIterator test kind="match_name_test" qname="xs:QName(,,id)" typename="*" nill allowed="0">
+                <ForVarIterator varname="p"/>
+              </AttributeAxisIterator>
+            </FnDataIterator>
           </HoistIterator>
         </LetVariable>
         <ForVariable name="a">
 
=== modified file 'test/rbkt/ExpCompilerResults/IterPlan/zorba/hashjoins/idx2.iter'
--- test/rbkt/ExpCompilerResults/IterPlan/zorba/hashjoins/idx2.iter	2012-09-19 21:16:15 +0000
+++ test/rbkt/ExpCompilerResults/IterPlan/zorba/hashjoins/idx2.iter	2012-12-06 22:51:20 +0000
@@ -36,13 +36,11 @@
   </LetVariable>
   <LetVariable name="$$opt_temp_1" materialize="true">
     <HoistIterator>
-      <CastIterator type="xs:string">
-        <FnDataIterator>
-          <AttributeAxisIterator test kind="match_name_test" qname="xs:QName(,,id)" typename="*" nill allowed="0">
-            <ForVarIterator varname="p"/>
-          </AttributeAxisIterator>
-        </FnDataIterator>
-      </CastIterator>
+      <FnDataIterator>
+        <AttributeAxisIterator test kind="match_name_test" qname="xs:QName(,,id)" typename="*" nill allowed="0">
+          <ForVarIterator varname="p"/>
+        </AttributeAxisIterator>
+      </FnDataIterator>
     </HoistIterator>
   </LetVariable>
   <ForVariable name="a">
@@ -58,17 +56,15 @@
   <WhereClause>
     <FnBooleanIterator>
       <TypedValueCompareIterator_STRING>
-        <CastIterator type="xs:string">
-          <PromoteIterator type="xs:anyAtomicType">
-            <FnDataIterator>
-              <AttributeAxisIterator test kind="match_name_test" qname="xs:QName(,,person)" typename="*" nill allowed="0">
-                <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,buyer)" typename="*" nill allowed="0">
-                  <ForVarIterator varname="t"/>
-                </ChildAxisIterator>
-              </AttributeAxisIterator>
-            </FnDataIterator>
-          </PromoteIterator>
-        </CastIterator>
+        <PromoteIterator type="xs:anyAtomicType">
+          <FnDataIterator>
+            <AttributeAxisIterator test kind="match_name_test" qname="xs:QName(,,person)" typename="*" nill allowed="0">
+              <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,buyer)" typename="*" nill allowed="0">
+                <ForVarIterator varname="t"/>
+              </ChildAxisIterator>
+            </AttributeAxisIterator>
+          </FnDataIterator>
+        </PromoteIterator>
         <UnhoistIterator>
           <LetVarIterator varname="$$opt_temp_1"/>
         </UnhoistIterator>
 
=== modified file 'test/rbkt/ExpCompilerResults/IterPlan/zorba/hashjoins/idx5.iter'
--- test/rbkt/ExpCompilerResults/IterPlan/zorba/hashjoins/idx5.iter	2012-10-08 12:09:36 +0000
+++ test/rbkt/ExpCompilerResults/IterPlan/zorba/hashjoins/idx5.iter	2012-12-06 22:51:20 +0000
@@ -19,94 +19,40 @@
       <SingletonIterator value="xs:QName(,,tests)"/>
     </ElementIterator>
   </CtxVarDeclareIterator>
-  <SequentialIterator>
-    <CreateInternalIndexIterator name="xs:QName(,,tempIndex0)">
+  <flwor::FLWORIterator>
+    <LetVariable name="test_old" materialize="true">
       <flwor::FLWORIterator>
-        <ForVariable name="$$opt_temp_2">
+        <ForVariable name="$$context-item">
           <CtxVarIterator varid="4" varname="tests" varkind="global"/>
         </ForVariable>
+        <WhereClause>
+          <FnBooleanIterator>
+            <TypedValueCompareIterator_STRING>
+              <PromoteIterator type="xs:anyAtomicType">
+                <FnDataIterator>
+                  <ChildAxisIterator test kind="match_text_test" qname="*" typename="*" nill allowed="0">
+                    <ForVarIterator varname="$$context-item"/>
+                  </ChildAxisIterator>
+                </FnDataIterator>
+              </PromoteIterator>
+              <PromoteIterator type="xs:anyAtomicType">
+                <FnDataIterator>
+                  <ChildAxisIterator test kind="match_text_test" qname="*" typename="*" nill allowed="0">
+                    <CtxVarIterator varid="4" varname="tests" varkind="global"/>
+                  </ChildAxisIterator>
+                </FnDataIterator>
+              </PromoteIterator>
+            </TypedValueCompareIterator_STRING>
+          </FnBooleanIterator>
+        </WhereClause>
         <ReturnClause>
-          <ValueIndexEntryBuilderIterator>
-            <ForVarIterator varname="$$opt_temp_2"/>
-            <CastIterator type="xs:string">
-              <PromoteIterator type="xs:anyAtomicType">
-                <FnDataIterator>
-                  <ChildAxisIterator test kind="match_text_test" qname="*" typename="*" nill allowed="0">
-                    <TreatIterator type="[NodeXQType anyNode content=[XQType ANY_TYPE_KIND*]]" quant="*">
-                      <ForVarIterator varname="$$opt_temp_2"/>
-                    </TreatIterator>
-                  </ChildAxisIterator>
-                </FnDataIterator>
-              </PromoteIterator>
-            </CastIterator>
-          </ValueIndexEntryBuilderIterator>
+          <ForVarIterator varname="$$context-item"/>
         </ReturnClause>
       </flwor::FLWORIterator>
-    </CreateInternalIndexIterator>
-    <flwor::FLWORIterator>
-      <LetVariable name="$$opt_temp_1" materialize="true">
-        <HoistIterator>
-          <flwor::FLWORIterator>
-            <ForVariable name="$$context-item">
-              <CtxVarIterator varid="4" varname="tests" varkind="global"/>
-            </ForVariable>
-            <WhereClause>
-              <FnBooleanIterator>
-                <AttributeAxisIterator test kind="match_name_test" qname="xs:QName(,,name)" typename="*" nill allowed="0">
-                  <TreatIterator type="[NodeXQType anyNode content=[XQType ANY_TYPE_KIND*]]" quant="*">
-                    <ForVarIterator varname="$$context-item"/>
-                  </TreatIterator>
-                </AttributeAxisIterator>
-              </FnBooleanIterator>
-            </WhereClause>
-            <ReturnClause>
-              <ForVarIterator varname="$$context-item"/>
-            </ReturnClause>
-          </flwor::FLWORIterator>
-        </HoistIterator>
-      </LetVariable>
-      <ForVariable name="test">
-        <CtxVarIterator varid="4" varname="tests" varkind="global"/>
-      </ForVariable>
-      <LetVariable name="$$opt_temp_0" materialize="true">
-        <HoistIterator>
-          <CastIterator type="xs:string">
-            <PromoteIterator type="xs:anyAtomicType">
-              <FnDataIterator>
-                <ChildAxisIterator test kind="match_text_test" qname="*" typename="*" nill allowed="0">
-                  <TreatIterator type="[NodeXQType anyNode content=[XQType ANY_TYPE_KIND*]]" quant="*">
-                    <ForVarIterator varname="test"/>
-                  </TreatIterator>
-                </ChildAxisIterator>
-              </FnDataIterator>
-            </PromoteIterator>
-          </CastIterator>
-        </HoistIterator>
-      </LetVariable>
-      <LetVariable name="test_old" materialize="true">
-        <flwor::FLWORIterator>
-          <ForVariable name="$$context-item">
-            <ProbeIndexPointValueIterator>
-              <SingletonIterator value="xs:QName(,,tempIndex0)"/>
-              <UnhoistIterator>
-                <LetVarIterator varname="$$opt_temp_0"/>
-              </UnhoistIterator>
-            </ProbeIndexPointValueIterator>
-          </ForVariable>
-          <ReturnClause>
-            <ForVarIterator varname="$$context-item"/>
-          </ReturnClause>
-        </flwor::FLWORIterator>
-      </LetVariable>
-      <LetVariable name="qt_old" materialize="true">
-        <UnhoistIterator>
-          <LetVarIterator varname="$$opt_temp_1"/>
-        </UnhoistIterator>
-      </LetVariable>
-      <ReturnClause>
-        <SingletonIterator value="xs:integer(1)"/>
-      </ReturnClause>
-    </flwor::FLWORIterator>
-  </SequentialIterator>
+    </LetVariable>
+    <ReturnClause>
+      <SingletonIterator value="xs:integer(1)"/>
+    </ReturnClause>
+  </flwor::FLWORIterator>
 </SequentialIterator>
 
 
=== modified file 'test/rbkt/ExpCompilerResults/IterPlan/zorba/no-copy/dataguide-c.iter'
--- test/rbkt/ExpCompilerResults/IterPlan/zorba/no-copy/dataguide-c.iter	2012-10-08 12:09:36 +0000
+++ test/rbkt/ExpCompilerResults/IterPlan/zorba/no-copy/dataguide-c.iter	2012-12-06 22:51:20 +0000
@@ -46,16 +46,8 @@
   <SequentialIterator>
     <ApplyIterator>
       <MapCreateIterator>
-        <PromoteIterator type="xs:QName">
-          <FnDataIterator>
-            <CtxVarIterator varid="5" varname="map1" varkind="global"/>
-          </FnDataIterator>
-        </PromoteIterator>
-        <PromoteIterator type="xs:QName">
-          <FnDataIterator>
-            <CtxVarIterator varid="6" varname="str" varkind="global"/>
-          </FnDataIterator>
-        </PromoteIterator>
+        <CtxVarIterator varid="5" varname="map1" varkind="global"/>
+        <CtxVarIterator varid="6" varname="str" varkind="global"/>
       </MapCreateIterator>
     </ApplyIterator>
     <CtxVarDeclareIterator varid="8" varname="DG">
@@ -69,11 +61,7 @@
     </CtxVarDeclareIterator>
     <ApplyIterator>
       <MapDestroyIterator>
-        <PromoteIterator type="xs:QName">
-          <FnDataIterator>
-            <CtxVarIterator varid="5" varname="map1" varkind="global"/>
-          </FnDataIterator>
-        </PromoteIterator>
+        <CtxVarIterator varid="5" varname="map1" varkind="global"/>
       </MapDestroyIterator>
     </ApplyIterator>
     <CtxVarIterator varid="8" varname="DG" varkind="local"/>
@@ -195,11 +183,7 @@
       <CtxVarAssignIterator varid="1" varname="label" varkind="local">
         <TreatIterator type="xs:integer" quant="?">
           <MapGetIterator>
-            <PromoteIterator type="xs:QName">
-              <FnDataIterator>
-                <CtxVarIterator varid="5" varname="map1" varkind="global"/>
-              </FnDataIterator>
-            </PromoteIterator>
+            <CtxVarIterator varid="5" varname="map1" varkind="global"/>
             <PromoteIterator type="xs:anyAtomicType">
               <FnDataIterator>
                 <CtxVarIterator varid="4" varname="s2" varkind="local"/>
@@ -224,11 +208,7 @@
           </CtxVarAssignIterator>
           <ApplyIterator>
             <MapInsertIterator>
-              <PromoteIterator type="xs:QName">
-                <FnDataIterator>
-                  <CtxVarIterator varid="5" varname="map1" varkind="global"/>
-                </FnDataIterator>
-              </PromoteIterator>
+              <CtxVarIterator varid="5" varname="map1" varkind="global"/>
               <CtxVarIterator varid="4" varname="co" varkind="global"/>
               <PromoteIterator type="xs:anyAtomicType">
                 <FnDataIterator>
 
=== modified file 'test/rbkt/ExpCompilerResults/IterPlan/zorba/no-copy/dataguide-nc.iter'
--- test/rbkt/ExpCompilerResults/IterPlan/zorba/no-copy/dataguide-nc.iter	2012-10-08 12:09:36 +0000
+++ test/rbkt/ExpCompilerResults/IterPlan/zorba/no-copy/dataguide-nc.iter	2012-12-06 22:51:20 +0000
@@ -46,16 +46,8 @@
   <SequentialIterator>
     <ApplyIterator>
       <MapCreateIterator>
-        <PromoteIterator type="xs:QName">
-          <FnDataIterator>
-            <CtxVarIterator varid="5" varname="map1" varkind="global"/>
-          </FnDataIterator>
-        </PromoteIterator>
-        <PromoteIterator type="xs:QName">
-          <FnDataIterator>
-            <CtxVarIterator varid="6" varname="str" varkind="global"/>
-          </FnDataIterator>
-        </PromoteIterator>
+        <CtxVarIterator varid="5" varname="map1" varkind="global"/>
+        <CtxVarIterator varid="6" varname="str" varkind="global"/>
       </MapCreateIterator>
     </ApplyIterator>
     <CtxVarDeclareIterator varid="8" varname="DG">
@@ -69,11 +61,7 @@
     </CtxVarDeclareIterator>
     <ApplyIterator>
       <MapDestroyIterator>
-        <PromoteIterator type="xs:QName">
-          <FnDataIterator>
-            <CtxVarIterator varid="5" varname="map1" varkind="global"/>
-          </FnDataIterator>
-        </PromoteIterator>
+        <CtxVarIterator varid="5" varname="map1" varkind="global"/>
       </MapDestroyIterator>
     </ApplyIterator>
     <CtxVarIterator varid="8" varname="DG" varkind="local"/>
@@ -195,11 +183,7 @@
       <CtxVarAssignIterator varid="1" varname="label" varkind="local">
         <TreatIterator type="xs:integer" quant="?">
           <MapGetIterator>
-            <PromoteIterator type="xs:QName">
-              <FnDataIterator>
-                <CtxVarIterator varid="5" varname="map1" varkind="global"/>
-              </FnDataIterator>
-            </PromoteIterator>
+            <CtxVarIterator varid="5" varname="map1" varkind="global"/>
             <PromoteIterator type="xs:anyAtomicType">
               <FnDataIterator>
                 <CtxVarIterator varid="4" varname="s2" varkind="local"/>
@@ -224,11 +208,7 @@
           </CtxVarAssignIterator>
           <ApplyIterator>
             <MapInsertIterator>
-              <PromoteIterator type="xs:QName">
-                <FnDataIterator>
-                  <CtxVarIterator varid="5" varname="map1" varkind="global"/>
-                </FnDataIterator>
-              </PromoteIterator>
+              <CtxVarIterator varid="5" varname="map1" varkind="global"/>
               <CtxVarIterator varid="4" varname="co" varkind="global"/>
               <PromoteIterator type="xs:anyAtomicType">
                 <FnDataIterator>
 
=== modified file 'test/rbkt/ExpCompilerResults/IterPlan/zorba/no-copy/hashjoin-idx1.iter'
--- test/rbkt/ExpCompilerResults/IterPlan/zorba/no-copy/hashjoin-idx1.iter	2012-09-19 21:16:15 +0000
+++ test/rbkt/ExpCompilerResults/IterPlan/zorba/no-copy/hashjoin-idx1.iter	2012-12-06 22:51:20 +0000
@@ -28,17 +28,15 @@
           <ReturnClause>
             <ValueIndexEntryBuilderIterator>
               <ForVarIterator varname="$$opt_temp_3"/>
-              <CastIterator type="xs:string">
-                <PromoteIterator type="xs:anyAtomicType">
-                  <FnDataIterator>
-                    <AttributeAxisIterator test kind="match_name_test" qname="xs:QName(,,person)" typename="*" nill allowed="0">
-                      <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,buyer)" typename="*" nill allowed="0">
-                        <ForVarIterator varname="$$opt_temp_3"/>
-                      </ChildAxisIterator>
-                    </AttributeAxisIterator>
-                  </FnDataIterator>
-                </PromoteIterator>
-              </CastIterator>
+              <PromoteIterator type="xs:anyAtomicType">
+                <FnDataIterator>
+                  <AttributeAxisIterator test kind="match_name_test" qname="xs:QName(,,person)" typename="*" nill allowed="0">
+                    <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,buyer)" typename="*" nill allowed="0">
+                      <ForVarIterator varname="$$opt_temp_3"/>
+                    </ChildAxisIterator>
+                  </AttributeAxisIterator>
+                </FnDataIterator>
+              </PromoteIterator>
             </ValueIndexEntryBuilderIterator>
           </ReturnClause>
         </flwor::FLWORIterator>
@@ -66,13 +64,11 @@
         </LetVariable>
         <LetVariable name="$$opt_temp_1" materialize="true">
           <HoistIterator>
-            <CastIterator type="xs:string">
-              <FnDataIterator>
-                <AttributeAxisIterator test kind="match_name_test" qname="xs:QName(,,id)" typename="*" nill allowed="0">
-                  <ForVarIterator varname="p"/>
-                </AttributeAxisIterator>
-              </FnDataIterator>
-            </CastIterator>
+            <FnDataIterator>
+              <AttributeAxisIterator test kind="match_name_test" qname="xs:QName(,,id)" typename="*" nill allowed="0">
+                <ForVarIterator varname="p"/>
+              </AttributeAxisIterator>
+            </FnDataIterator>
           </HoistIterator>
         </LetVariable>
         <ForVariable name="a">
 
=== modified file 'test/rbkt/ExpCompilerResults/IterPlan/zorba/no-copy/node-copy-01.iter'
--- test/rbkt/ExpCompilerResults/IterPlan/zorba/no-copy/node-copy-01.iter	2012-10-05 08:48:49 +0000
+++ test/rbkt/ExpCompilerResults/IterPlan/zorba/no-copy/node-copy-01.iter	2012-12-06 22:51:20 +0000
@@ -20,13 +20,9 @@
             <SingletonIterator value="xs:QName(,,node)"/>
             <FnConcatIterator/>
             <EnclosedIterator attr_cont="false">
-              <NodeSortIterator distinct="true" ascending="true">
-                <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,b)" typename="*" nill allowed="0">
-                  <TreatIterator type="[NodeXQType anyNode content=[XQType ANY_TYPE_KIND*]]" quant="*">
-                    <CtxVarIterator varid="4" varname="doc" varkind="global"/>
-                  </TreatIterator>
-                </ChildAxisIterator>
-              </NodeSortIterator>
+              <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,b)" typename="*" nill allowed="0">
+                <CtxVarIterator varid="4" varname="doc" varkind="global"/>
+              </ChildAxisIterator>
             </EnclosedIterator>
           </ElementIterator>
         </ChildAxisIterator>
 
=== modified file 'test/rbkt/ExpCompilerResults/IterPlan/zorba/no-copy/node-copy-02.iter'
--- test/rbkt/ExpCompilerResults/IterPlan/zorba/no-copy/node-copy-02.iter	2012-10-05 08:48:49 +0000
+++ test/rbkt/ExpCompilerResults/IterPlan/zorba/no-copy/node-copy-02.iter	2012-12-06 22:51:20 +0000
@@ -1,12 +1,12 @@
 Iterator tree for main query:
 <SequentialIterator>
   <CtxVarDeclareIterator varid="4" varname="doc">
-    <ElementIterator>
+    <ElementIterator copyInputNodes="false">
       <SingletonIterator value="xs:QName(,,a)"/>
       <FnConcatIterator/>
-      <ElementIterator>
+      <ElementIterator copyInputNodes="false">
         <SingletonIterator value="xs:QName(,,b)"/>
-        <ElementIterator>
+        <ElementIterator copyInputNodes="false">
           <SingletonIterator value="xs:QName(,,c)"/>
         </ElementIterator>
       </ElementIterator>
@@ -20,13 +20,9 @@
             <SingletonIterator value="xs:QName(,,node)"/>
             <FnConcatIterator/>
             <EnclosedIterator attr_cont="false">
-              <NodeSortIterator distinct="true" ascending="true">
-                <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,b)" typename="*" nill allowed="0">
-                  <TreatIterator type="[NodeXQType anyNode content=[XQType ANY_TYPE_KIND*]]" quant="*">
-                    <CtxVarIterator varid="4" varname="doc" varkind="global"/>
-                  </TreatIterator>
-                </ChildAxisIterator>
-              </NodeSortIterator>
+              <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,b)" typename="*" nill allowed="0">
+                <CtxVarIterator varid="4" varname="doc" varkind="global"/>
+              </ChildAxisIterator>
             </EnclosedIterator>
           </ElementIterator>
         </ChildAxisIterator>
 
=== modified file 'test/rbkt/ExpCompilerResults/IterPlan/zorba/no-copy/node-copy-03.iter'
--- test/rbkt/ExpCompilerResults/IterPlan/zorba/no-copy/node-copy-03.iter	2012-10-05 08:48:49 +0000
+++ test/rbkt/ExpCompilerResults/IterPlan/zorba/no-copy/node-copy-03.iter	2012-12-06 22:51:20 +0000
@@ -1,12 +1,12 @@
 Iterator tree for main query:
 <SequentialIterator>
   <CtxVarDeclareIterator varid="4" varname="doc">
-    <ElementIterator>
+    <ElementIterator copyInputNodes="false">
       <SingletonIterator value="xs:QName(,,a)"/>
       <FnConcatIterator/>
-      <ElementIterator>
+      <ElementIterator copyInputNodes="false">
         <SingletonIterator value="xs:QName(,,b)"/>
-        <ElementIterator>
+        <ElementIterator copyInputNodes="false">
           <SingletonIterator value="xs:QName(,,c)"/>
         </ElementIterator>
       </ElementIterator>
@@ -20,13 +20,9 @@
             <SingletonIterator value="xs:QName(,,node)"/>
             <FnConcatIterator/>
             <EnclosedIterator attr_cont="false">
-              <NodeSortIterator distinct="true" ascending="true">
-                <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,b)" typename="*" nill allowed="0">
-                  <TreatIterator type="[NodeXQType anyNode content=[XQType ANY_TYPE_KIND*]]" quant="*">
-                    <CtxVarIterator varid="4" varname="doc" varkind="global"/>
-                  </TreatIterator>
-                </ChildAxisIterator>
-              </NodeSortIterator>
+              <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,b)" typename="*" nill allowed="0">
+                <CtxVarIterator varid="4" varname="doc" varkind="global"/>
+              </ChildAxisIterator>
             </EnclosedIterator>
           </ElementIterator>
         </ChildAxisIterator>
 
=== modified file 'test/rbkt/ExpCompilerResults/IterPlan/zorba/optim/positioned-access.iter'
--- test/rbkt/ExpCompilerResults/IterPlan/zorba/optim/positioned-access.iter	2012-10-08 12:09:36 +0000
+++ test/rbkt/ExpCompilerResults/IterPlan/zorba/optim/positioned-access.iter	2012-12-06 22:51:20 +0000
@@ -17,11 +17,7 @@
     <FunctionTraceIterator>
       <flwor::FLWORIterator>
         <LetVariable name="x" materialize="true">
-          <PromoteIterator type="xs:integer">
-            <FnDataIterator>
-              <CtxVarIterator varid="4" varname="n1" varkind="global"/>
-            </FnDataIterator>
-          </PromoteIterator>
+          <CtxVarIterator varid="4" varname="n1" varkind="global"/>
         </LetVariable>
         <ReturnClause>
           <LetVarIterator varname="x">
@@ -35,11 +31,7 @@
     <FunctionTraceIterator>
       <flwor::FLWORIterator>
         <LetVariable name="x" materialize="true">
-          <PromoteIterator type="xs:integer">
-            <FnDataIterator>
-              <CtxVarIterator varid="5" varname="n2" varkind="global"/>
-            </FnDataIterator>
-          </PromoteIterator>
+          <CtxVarIterator varid="5" varname="n2" varkind="global"/>
         </LetVariable>
         <ReturnClause>
           <LetVarIterator varname="x">
 
=== modified file 'test/rbkt/ExpCompilerResults/IterPlan/zorba/optim/var_inline_01.iter'
--- test/rbkt/ExpCompilerResults/IterPlan/zorba/optim/var_inline_01.iter	2012-10-08 12:09:36 +0000
+++ test/rbkt/ExpCompilerResults/IterPlan/zorba/optim/var_inline_01.iter	2012-12-06 22:51:20 +0000
@@ -17,47 +17,32 @@
         <SingletonIterator value="xs:integer(2)"/>
       </NumArithIterator_ModOperation>
     </ForVariable>
-    <LetVariable name="foo" materialize="true">
+    <ForVariable name="foo">
       <CtxVarIterator varid="4" varname="g" varkind="global"/>
-    </LetVariable>
-    <LetVariable name="$$opt_temp_0" materialize="true">
-      <HoistIterator>
-        <PromoteIterator type="xs:anyAtomicType">
-          <FnDataIterator>
-            <LetVarIterator varname="foo"/>
-          </FnDataIterator>
-        </PromoteIterator>
-      </HoistIterator>
-    </LetVariable>
+    </ForVariable>
     <WhereClause>
-      <CompareIterator>
-        <FnSumIterator>
+      <TypedValueCompareIterator_INTEGER>
+        <FnSumIntegerIterator>
           <flwor::FLWORIterator>
             <ForVariable name="z">
               <FnConcatIterator>
                 <SingletonIterator value="xs:integer(5)"/>
-                <LetVarIterator varname="foo"/>
+                <ForVarIterator varname="foo"/>
               </FnConcatIterator>
             </ForVariable>
             <ReturnClause>
-              <GenericArithIterator_AddOperation>
-                <GenericArithIterator_MultiplyOperation>
-                  <PromoteIterator type="xs:anyAtomicType">
-                    <FnDataIterator>
-                      <ForVarIterator varname="z"/>
-                    </FnDataIterator>
-                  </PromoteIterator>
+              <SpecificNumArithIterator_AddOperation_INTEGER>
+                <SpecificNumArithIterator_MultiplyOperation_INTEGER>
+                  <ForVarIterator varname="z"/>
                   <ForVarIterator varname="y"/>
-                </GenericArithIterator_MultiplyOperation>
-                <UnhoistIterator>
-                  <LetVarIterator varname="$$opt_temp_0"/>
-                </UnhoistIterator>
-              </GenericArithIterator_AddOperation>
+                </SpecificNumArithIterator_MultiplyOperation_INTEGER>
+                <ForVarIterator varname="foo"/>
+              </SpecificNumArithIterator_AddOperation_INTEGER>
             </ReturnClause>
           </flwor::FLWORIterator>
-        </FnSumIterator>
+        </FnSumIntegerIterator>
         <SingletonIterator value="xs:integer(8)"/>
-      </CompareIterator>
+      </TypedValueCompareIterator_INTEGER>
     </WhereClause>
     <ReturnClause>
       <ForVarIterator varname="x"/>
 
=== modified file 'test/rbkt/ExpCompilerResults/IterPlan/zorba/udf/udf1.iter'
--- test/rbkt/ExpCompilerResults/IterPlan/zorba/udf/udf1.iter	2012-10-08 12:09:36 +0000
+++ test/rbkt/ExpCompilerResults/IterPlan/zorba/udf/udf1.iter	2012-12-06 22:51:20 +0000
@@ -31,11 +31,7 @@
         </ElementIterator>
       </DescendantAxisIterator>
     </ChildAxisIterator>
-    <PromoteIterator type="xs:integer">
-      <FnDataIterator>
-        <CtxVarIterator varid="4" varname="x" varkind="global"/>
-      </FnDataIterator>
-    </PromoteIterator>
+    <CtxVarIterator varid="4" varname="x" varkind="global"/>
   </UDFunctionCallIterator>
 </SequentialIterator>
 
 
=== modified file 'test/rbkt/ExpCompilerResults/IterPlan/zorba/windowing/q10.iter'
--- test/rbkt/ExpCompilerResults/IterPlan/zorba/windowing/q10.iter	2012-10-08 12:09:36 +0000
+++ test/rbkt/ExpCompilerResults/IterPlan/zorba/windowing/q10.iter	2012-12-06 22:51:20 +0000
@@ -32,13 +32,9 @@
               <NodeSortIterator distinct="true" ascending="true">
                 <flwor::FLWORIterator>
                   <ForVariable name="$$context-item">
-                    <NodeDistinctIterator allow-atomics="false" check-only="false">
-                      <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,stream)" typename="*" nill allowed="0">
-                        <TreatIterator type="[NodeXQType anyNode content=[XQType ANY_TYPE_KIND*]]" quant="*">
-                          <CtxVarIterator varid="4" varname="seq" varkind="global"/>
-                        </TreatIterator>
-                      </ChildAxisIterator>
-                    </NodeDistinctIterator>
+                    <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,stream)" typename="*" nill allowed="0">
+                      <CtxVarIterator varid="4" varname="seq" varkind="global"/>
+                    </ChildAxisIterator>
                   </ForVariable>
                   <ForVariable name="$$context-item">
                     <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,event)" typename="*" nill allowed="0">
@@ -47,7 +43,7 @@
                   </ForVariable>
                   <WhereClause>
                     <FnBooleanIterator>
-                      <CompareIterator>
+                      <TypedValueCompareIterator_STRING>
                         <PromoteIterator type="xs:anyAtomicType">
                           <FnDataIterator>
                             <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,direction)" typename="*" nill allowed="0">
@@ -56,7 +52,7 @@
                           </FnDataIterator>
                         </PromoteIterator>
                         <SingletonIterator value="xs:string(in)"/>
-                      </CompareIterator>
+                      </TypedValueCompareIterator_STRING>
                     </FnBooleanIterator>
                   </WhereClause>
                   <ReturnClause>
@@ -100,7 +96,7 @@
               </ForVariable>
               <WhereClause>
                 <FnBooleanIterator>
-                  <CompareIterator>
+                  <TypedValueCompareIterator_STRING>
                     <PromoteIterator type="xs:anyAtomicType">
                       <FnDataIterator>
                         <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,person)" typename="*" nill allowed="0">
@@ -109,7 +105,7 @@
                       </FnDataIterator>
                     </PromoteIterator>
                     <SingletonIterator value="xs:string(Barbara)"/>
-                  </CompareIterator>
+                  </TypedValueCompareIterator_STRING>
                 </FnBooleanIterator>
               </WhereClause>
               <ReturnClause>
 
=== modified file 'test/rbkt/ExpCompilerResults/IterPlan/zorba/windowing/q4.iter'
--- test/rbkt/ExpCompilerResults/IterPlan/zorba/windowing/q4.iter	2012-10-08 12:09:36 +0000
+++ test/rbkt/ExpCompilerResults/IterPlan/zorba/windowing/q4.iter	2012-12-06 22:51:20 +0000
@@ -1,6 +1,11 @@
 Iterator tree for const-folded expr:
 <SingletonIterator value="xs:integer(2)"/>
 
+Iterator tree for const-folded expr:
+<PromoteIterator type="xs:double">
+  <SingletonIterator value="xs:integer(2)"/>
+</PromoteIterator>
+
 Iterator tree for main query:
 <SequentialIterator>
   <CtxVarDeclareIterator varid="4" varname="timesequence">
@@ -11,60 +16,52 @@
   <flwor::TupleStreamIterator>
     <flwor::WindowIterator>
       <WindowVariable name="w">
-        <NodeSortIterator distinct="true" ascending="true">
-          <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,event)" typename="*" nill allowed="0">
-            <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,stream)" typename="*" nill allowed="0">
-              <TreatIterator type="[NodeXQType anyNode content=[XQType ANY_TYPE_KIND*]]" quant="*">
-                <CtxVarIterator varid="4" varname="timesequence" varkind="global"/>
-              </TreatIterator>
-            </ChildAxisIterator>
+        <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,event)" typename="*" nill allowed="0">
+          <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,stream)" typename="*" nill allowed="0">
+            <CtxVarIterator varid="4" varname="timesequence" varkind="global"/>
           </ChildAxisIterator>
-        </NodeSortIterator>
+        </ChildAxisIterator>
       </WindowVariable>
       <WinCondVariable name="start-CurrentIn"/>
       <WinCondVariable name="start-CurrentInPrevIn"/>
       <OrIterator>
-        <CompareIterator>
-          <PromoteIterator type="xs:anyAtomicType">
-            <FnDataIterator>
-              <AttributeAxisIterator test kind="match_name_test" qname="xs:QName(,,time)" typename="*" nill allowed="0">
-                <ForVarIterator varname="s_curr"/>
-              </AttributeAxisIterator>
-            </FnDataIterator>
-          </PromoteIterator>
-          <PromoteIterator type="xs:anyAtomicType">
-            <FnDataIterator>
-              <AttributeAxisIterator test kind="match_name_test" qname="xs:QName(,,time)" typename="*" nill allowed="0">
-                <ForVarIterator varname="s_prev"/>
-              </AttributeAxisIterator>
-            </FnDataIterator>
-          </PromoteIterator>
-        </CompareIterator>
+        <TypedValueCompareIterator_STRING>
+          <FnDataIterator>
+            <AttributeAxisIterator test kind="match_name_test" qname="xs:QName(,,time)" typename="*" nill allowed="0">
+              <ForVarIterator varname="s_curr"/>
+            </AttributeAxisIterator>
+          </FnDataIterator>
+          <FnDataIterator>
+            <AttributeAxisIterator test kind="match_name_test" qname="xs:QName(,,time)" typename="*" nill allowed="0">
+              <ForVarIterator varname="s_prev"/>
+            </AttributeAxisIterator>
+          </FnDataIterator>
+        </TypedValueCompareIterator_STRING>
         <FnEmptyIterator>
           <ForVarIterator varname="s_prev"/>
         </FnEmptyIterator>
       </OrIterator>
       <WinCondVariable name="end-NextIn"/>
       <FnBooleanIterator>
-        <CompareIterator>
-          <GenericArithIterator_SubtractOperation>
-            <PromoteIterator type="xs:anyAtomicType">
+        <TypedValueCompareIterator_DOUBLE>
+          <SpecificNumArithIterator_SubtractOperation_DOUBLE>
+            <PromoteIterator type="xs:double">
               <FnDataIterator>
                 <AttributeAxisIterator test kind="match_name_test" qname="xs:QName(,,time)" typename="*" nill allowed="0">
                   <ForVarIterator varname="e_next"/>
                 </AttributeAxisIterator>
               </FnDataIterator>
             </PromoteIterator>
-            <PromoteIterator type="xs:anyAtomicType">
+            <PromoteIterator type="xs:double">
               <FnDataIterator>
                 <AttributeAxisIterator test kind="match_name_test" qname="xs:QName(,,time)" typename="*" nill allowed="0">
                   <ForVarIterator varname="s_curr"/>
                 </AttributeAxisIterator>
               </FnDataIterator>
             </PromoteIterator>
-          </GenericArithIterator_SubtractOperation>
-          <SingletonIterator value="xs:integer(2)"/>
-        </CompareIterator>
+          </SpecificNumArithIterator_SubtractOperation_DOUBLE>
+          <SingletonIterator value="xs:double(2)"/>
+        </TypedValueCompareIterator_DOUBLE>
       </FnBooleanIterator>
       <flwor::TupleSourceIterator/>
     </flwor::WindowIterator>
 
=== modified file 'test/rbkt/ExpCompilerResults/IterPlan/zorba/windowing/q9.iter'
--- test/rbkt/ExpCompilerResults/IterPlan/zorba/windowing/q9.iter	2012-10-08 12:09:36 +0000
+++ test/rbkt/ExpCompilerResults/IterPlan/zorba/windowing/q9.iter	2012-12-06 22:51:20 +0000
@@ -14,20 +14,16 @@
             <LetVariable name="person" materialize="true"/>
             <flwor::WindowIterator>
               <WindowVariable name="w">
-                <NodeSortIterator distinct="true" ascending="true">
-                  <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,event)" typename="*" nill allowed="0">
-                    <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,stream)" typename="*" nill allowed="0">
-                      <TreatIterator type="[NodeXQType anyNode content=[XQType ANY_TYPE_KIND*]]" quant="*">
-                        <CtxVarIterator varid="4" varname="seq" varkind="global"/>
-                      </TreatIterator>
-                    </ChildAxisIterator>
+                <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,event)" typename="*" nill allowed="0">
+                  <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,stream)" typename="*" nill allowed="0">
+                    <CtxVarIterator varid="4" varname="seq" varkind="global"/>
                   </ChildAxisIterator>
-                </NodeSortIterator>
+                </ChildAxisIterator>
               </WindowVariable>
               <WinCondVariable name="start-CurrentIn"/>
               <WinCondVariable name="start-CurrentInCurrentOut"/>
               <FnBooleanIterator>
-                <CompareIterator>
+                <TypedValueCompareIterator_STRING>
                   <PromoteIterator type="xs:anyAtomicType">
                     <FnDataIterator>
                       <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,direction)" typename="*" nill allowed="0">
@@ -36,12 +32,12 @@
                     </FnDataIterator>
                   </PromoteIterator>
                   <SingletonIterator value="xs:string(in)"/>
-                </CompareIterator>
+                </TypedValueCompareIterator_STRING>
               </FnBooleanIterator>
               <WinCondVariable name="end-CurrentIn"/>
               <WinCondVariable name="end-CurrentInCurrentOut"/>
               <AndIterator>
-                <CompareIterator>
+                <TypedValueCompareIterator_STRING>
                   <PromoteIterator type="xs:anyAtomicType">
                     <FnDataIterator>
                       <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,person)" typename="*" nill allowed="0">
@@ -56,8 +52,8 @@
                       </ChildAxisIterator>
                     </FnDataIterator>
                   </PromoteIterator>
-                </CompareIterator>
-                <CompareIterator>
+                </TypedValueCompareIterator_STRING>
+                <TypedValueCompareIterator_STRING>
                   <PromoteIterator type="xs:anyAtomicType">
                     <FnDataIterator>
                       <ChildAxisIterator test kind="match_name_test" qname="xs:QName(,,direction)" typename="*" nill allowed="0">
@@ -66,7 +62,7 @@
                     </FnDataIterator>
                   </PromoteIterator>
                   <SingletonIterator value="xs:string(out)"/>
-                </CompareIterator>
+                </TypedValueCompareIterator_STRING>
               </AndIterator>
               <flwor::TupleSourceIterator/>
             </flwor::WindowIterator>
 
=== modified file 'test/rbkt/ExpCompilerResults/IterPlan/zorba/xray/ppm_10.iter'
--- test/rbkt/ExpCompilerResults/IterPlan/zorba/xray/ppm_10.iter	2012-10-08 12:09:36 +0000
+++ test/rbkt/ExpCompilerResults/IterPlan/zorba/xray/ppm_10.iter	2012-12-06 22:51:20 +0000
@@ -183,13 +183,6 @@
         </StringJoinIterator>
         <SingletonIterator value="xs:string(255)"/>
         <flwor::FLWORIterator>
-          <LetVariable name="$$opt_temp_1" materialize="true">
-            <HoistIterator>
-              <TreatIterator type="[NodeXQType elementNode content=[XQType ANY_TYPE_KIND*]]" quant="">
-                <CtxVarIterator varid="6" varname="scene" varkind="global"/>
-              </TreatIterator>
-            </HoistIterator>
-          </LetVariable>
           <LetVariable name="$$opt_temp_0" materialize="true">
             <HoistIterator>
               <OpToIterator>
@@ -221,7 +214,7 @@
               <SingletonIterator value="xs:decimal(0.5)"/>
             </SpecificNumArithIterator_AddOperation_DECIMAL>
           </ForVariable>
-          <LetVariable name="$$opt_temp_2" materialize="true">
+          <LetVariable name="$$opt_temp_1" materialize="true">
             <HoistIterator>
               <PromoteIterator type="xs:double">
                 <ForVarIterator varname="y-recentered"/>
@@ -238,9 +231,7 @@
               <flwor::FLWORIterator>
                 <ForVariable name="channel">
                   <UDFunctionCallIterator>
-                    <UnhoistIterator>
-                      <LetVarIterator varname="$$opt_temp_1"/>
-                    </UnhoistIterator>
+                    <CtxVarIterator varid="6" varname="scene" varkind="global"/>
                     <PromoteIterator type="xs:double">
                       <SpecificNumArithIterator_MultiplyOperation_DECIMAL>
                         <SpecificNumArithIterator_SubtractOperation_DECIMAL>
@@ -254,7 +245,7 @@
                       </SpecificNumArithIterator_MultiplyOperation_DECIMAL>
                     </PromoteIterator>
                     <UnhoistIterator>
-                      <LetVarIterator varname="$$opt_temp_2"/>
+                      <LetVarIterator varname="$$opt_temp_1"/>
                     </UnhoistIterator>
                   </UDFunctionCallIterator>
                 </ForVariable>
 
=== modified file 'test/rbkt/Queries/zorba/windowing/q4.xq'
--- test/rbkt/Queries/zorba/windowing/q4.xq	2012-09-19 21:16:15 +0000
+++ test/rbkt/Queries/zorba/windowing/q4.xq	2012-12-06 22:51:20 +0000
@@ -4,8 +4,8 @@
 
 for sliding window $w in $timesequence/stream/event 
   start $s_curr at $s_pos previous $s_prev
-    when ($s_curr/@time ne $s_prev/@time) or (empty($s_prev))
+  when ($s_curr/@time ne $s_prev/@time) or (empty($s_prev))
   only end next $e_next 
-    when $e_next/@time - $s_curr/@time gt $MAX_DIFF
+  when $e_next/@time - $s_curr/@time gt $MAX_DIFF
 return 
   avg( $w/@temp )