--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main/scala/AddOrderedSet.scala	Sun Jan 03 18:23:46 2010 -0500
@@ -0,0 +1,17 @@
+package w3c.sw
+import scala.collection.immutable._
+
+class AddOrderedSet[A](list:List[A]) extends Set[A] {
+
+  def contains(elem: A): Boolean = list.contains(elem)
+  def iterator: Iterator[A] = list.reverse.iterator
+  def + (elem: A) : AddOrderedSet[A] = if (this contains elem) this else new AddOrderedSet(elem :: list)
+  def - (elem: A) : AddOrderedSet[A] = new AddOrderedSet(list filterNot (_ == elem))
+
+}
+
+object AddOrderedSet {
+  def apply[A]():AddOrderedSet[A] = AddOrderedSet(List[A]())
+  def apply[A](list:List[A]):AddOrderedSet[A] = new AddOrderedSet(list)
+  def apply[A](args:A*):AddOrderedSet[A] = AddOrderedSet(args.toList)
+}

--- a/src/main/scala/RDB2RDFMain.scala	Sun Jan 03 03:01:12 2010 -0500
+++ b/src/main/scala/RDB2RDFMain.scala	Sun Jan 03 18:23:46 2010 -0500
@@ -13,7 +13,7 @@
 case class Enum(relaliasattr:RelAliasAttribute) extends Binding
 
 object RDB2RDF {
-  case class R2RState(joins:Set[Join], varmap:Map[Var, SQL2RDFValueMapper], exprs:Set[Expression])
+  case class R2RState(joins:AddOrderedSet[Join], varmap:Map[Var, SQL2RDFValueMapper], exprs:Set[Expression])
 
   sealed abstract class SQL2RDFValueMapper(relaliasattr:RelAliasAttribute, disjoints:Set[RelationalExpressionNe])
   case class IntMapper(relaliasattr:RelAliasAttribute, disjoints:Set[RelationalExpressionNe]) extends SQL2RDFValueMapper(relaliasattr, disjoints)
@@ -298,7 +298,7 @@
 	val unionAlias = RelAlias(Name("R_union" + state.joins.size))
 	val initDisjoints:Set[Select] = Set()
 	val emptyState = R2RState(
-	  Set[Join](), 
+	  AddOrderedSet[Join](), 
 	  Map[Var, SQL2RDFValueMapper](), 
 	  Set[Expression]()
 	)
@@ -376,7 +376,7 @@
       	val leftJoinAlias = RelAlias(Name("R_opt" + state.joins.size))
       	val initDisjoints:Set[Select] = Set()
       	val emptyState = R2RState(
-      	  Set[Join](), 
+      	  AddOrderedSet[Join](), 
       	  Map[Var, SQL2RDFValueMapper](), 
       	  Set[Expression]()
       	)
@@ -448,7 +448,7 @@
 
     /* Create an object to hold our compilation state. */
     val initState = R2RState(
-      Set[Join](), 
+      AddOrderedSet[Join](), 
       Map[Var, SQL2RDFValueMapper](), 
       Set[Expression]()
     )

--- a/src/main/scala/SQL.scala	Sun Jan 03 03:01:12 2010 -0500
+++ b/src/main/scala/SQL.scala	Sun Jan 03 18:23:46 2010 -0500
@@ -62,7 +62,7 @@
 case class RelAlias(n:Name) {
   override def toString = n.s /* "'" + n.s + "'" */
 }
-case class TableList(joins:Set[Join]) {
+case class TableList(joins:AddOrderedSet[Join]) {
   override def toString = "  FROM " + joins.foldLeft(("", 0))(
     (pair, entry) => (pair._1 + {
       if (pair._2 == 0) entry.toString.substring(19) // !!! shameless!
@@ -180,7 +180,7 @@
     """[a-zA-Z_]\w*""".r ^^ { x => RelAlias(Name(x)) }
 
   def tablelist:Parser[TableList] =
-    aliasedjoin ~ rep(innerORouter) ^^ { case aj~l => TableList(Set(InnerJoin(aj)) ++ l.toSet) }
+    aliasedjoin ~ rep(innerORouter) ^^ { case aj~l => TableList(AddOrderedSet(InnerJoin(aj) :: l)) }
 
   def innerORouter:Parser[Join] = (
       "INNER" ~ "JOIN" ~ aliasedjoin ^^ { case "INNER"~"JOIN"~a => InnerJoin(a) }

--- a/src/test/scala/SQLTest.scala	Sun Jan 03 03:01:12 2010 -0500
+++ b/src/test/scala/SQLTest.scala	Sun Jan 03 18:23:46 2010 -0500
@@ -62,7 +62,7 @@
 					     NamedAttribute(RelAliasAttribute(RelAlias(Name("R_manager")),
 									      Attribute(Name("lastName"))),
 							    AttrAlias(Name("A_managName"))))),
-			  TableList(Set(InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_emp")))),
+			  TableList(AddOrderedSet(InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_emp")))),
 					InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_manager")))))),
 			  Some(ExprConjunction(Set(
 			    RelationalExpressionEq(RelAliasAttribute(RelAlias(Name("R_manager")),Attribute(Name("id"))),
@@ -82,7 +82,7 @@
     val expected = Select(AttributeList(Set(NamedAttribute(RelAliasAttribute(RelAlias(Name("R_emp")),
 									      Attribute(Name("lastName"))),
 							    AttrAlias(Name("A_empName"))))),
-			  TableList(Set(InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_emp")))))),
+			  TableList(AddOrderedSet(InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_emp")))))),
 			  Some(ExprConjunction(Set(RelationalExpressionEq(RelAliasAttribute(RelAlias(Name("R_emp")),Attribute(Name("manager"))),
 							      RValueTyped(SQLDatatype.INTEGER,Name("18"))),
 					  RelationalExpressionNotNull(RelAliasAttribute(RelAlias(Name("R_emp")),Attribute(Name("lastName"))))))))
@@ -100,7 +100,7 @@
     val expected = Select(AttributeList(Set(NamedAttribute(RelAliasAttribute(RelAlias(Name("R_emp")),
 									      Attribute(Name("lastName"))),
 							    AttrAlias(Name("A_empName"))))),
-			  TableList(Set(InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_emp")))),
+			  TableList(AddOrderedSet(InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_emp")))),
 					InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_manager")))))),
 			  Some(ExprConjunction(Set(RelationalExpressionEq(RelAliasAttribute(RelAlias(Name("R_emp")),Attribute(Name("manager"))),
 							      RValueAttr(RelAliasAttribute(RelAlias(Name("R_manager")),Attribute(Name("id"))))),
@@ -129,7 +129,7 @@
 							   AttrAlias(Name("A_empName"))),
 					    NamedAttribute(RelAliasAttribute(RelAlias(Name("R_grandManager")),Attribute(Name("lastName"))),
 							   AttrAlias(Name("A_grandManagName"))))),
-			  TableList(Set(InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_emp")))),
+			  TableList(AddOrderedSet(InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_emp")))),
 					InnerJoin(AliasedResource(Relation(Name("Manage")),RelAlias(Name("R_lower")))),
 					InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_manager")))),
 					InnerJoin(AliasedResource(Relation(Name("Manage")),RelAlias(Name("R_upper")))),
@@ -171,13 +171,13 @@
 """
     val expected = Select(AttributeList(Set(NamedAttribute(RelAliasAttribute(RelAlias(Name("R_union1")), Attribute(Name("name"))),
 							   AttrAlias(Name("A_name"))))),
-			  TableList(Set(InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_who")))),
+			  TableList(AddOrderedSet(InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_who")))),
 					InnerJoin(AliasedResource(Subselect(Union(Set(
 					  Select(AttributeList(Set(NamedAttribute(RelAliasAttribute(RelAlias(Name("R_manager")), Attribute(Name("lastName"))),
 										  AttrAlias(Name("A_name"))), 
 								   NamedAttribute(RelAliasAttribute(RelAlias(Name("R_above")), Attribute(Name("manages"))),
 										  AttrAlias(Name("A_who"))))),
-						 TableList(Set(
+						 TableList(AddOrderedSet(
 						   InnerJoin(AliasedResource(Relation(Name("Manage")),RelAlias(Name("R_above")))),
 						   InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_manager"))))
 						 )), 
@@ -188,7 +188,7 @@
 										  AttrAlias(Name("A_name"))), 
 								   NamedAttribute(RelAliasAttribute(RelAlias(Name("R_below")), Attribute(Name("manager"))),
 										  AttrAlias(Name("A_who"))))),
-						 TableList(Set(
+						 TableList(AddOrderedSet(
 						   InnerJoin(AliasedResource(Relation(Name("Manage")),RelAlias(Name("R_below")))),
 						   InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_managed"))))
 						 )), 
@@ -215,7 +215,7 @@
 							    AttrAlias(Name("A_who"))),
 					     NamedAttribute(ConstNULL(),
 							    AttrAlias(Name("A_bday"))))),
-			  TableList(Set(InnerJoin(AliasedResource(Relation(Name("Manage")),RelAlias(Name("R_above")))))),
+			  TableList(AddOrderedSet(InnerJoin(AliasedResource(Relation(Name("Manage")),RelAlias(Name("R_above")))))),
 			  Some(
 			    RelationalExpressionNotNull(RelAliasAttribute(RelAlias(Name("R_above")),Attribute(Name("id"))))))
     assert(expected === (a.parseAll(a.select, e).get))
@@ -233,7 +233,7 @@
 							    AttrAlias(Name("A_who"))),
 					     NamedAttribute(ConstNULL(),
 							    AttrAlias(Name("A_bday"))))),
-			  TableList(Set(InnerJoin(AliasedResource(Relation(Name("Manage")),RelAlias(Name("R_above")))))),
+			  TableList(AddOrderedSet(InnerJoin(AliasedResource(Relation(Name("Manage")),RelAlias(Name("R_above")))))),
 			  Some(
 			    ExprDisjunction(Set(
 			      RelationalExpressionNotNull(RelAliasAttribute(RelAlias(Name("R_above")),Attribute(Name("id")))),
@@ -260,7 +260,7 @@
 					     NamedAttribute(RelAliasAttribute(RelAlias(Name("R_mang")),
 									      Attribute(Name("manageName"))),
 							    AttrAlias(Name("A_manageName"))))),
-			  TableList(Set(InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_emp")))),
+			  TableList(AddOrderedSet(InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_emp")))),
 					LeftOuterJoin(AliasedResource(Relation(Name("Manage")),RelAlias(Name("R_mang"))),
 						      RelationalExpressionEq(RelAliasAttribute(RelAlias(Name("R_mang")),Attribute(Name("emp"))),
 									     RValueAttr(RelAliasAttribute(RelAlias(Name("R_emp")),Attribute(Name("id"))))
@@ -286,11 +286,11 @@
     val expected = 
       Select(AttributeList(Set(NamedAttribute(RelAliasAttribute(RelAlias(Name("R_emp")),Attribute(Name("lastName"))),AttrAlias(Name("A_empName"))),
 			       NamedAttribute(RelAliasAttribute(RelAlias(Name("R_mang")),Attribute(Name("manageName"))),AttrAlias(Name("A_manageName"))))),
-	     TableList(Set(InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_emp")))),
+	     TableList(AddOrderedSet(InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_emp")))),
 			   LeftOuterJoin(AliasedResource(
 			     Subselect(Select(AttributeList(Set(NamedAttribute(RelAliasAttribute(RelAlias(Name("R_emp")),Attribute(Name("lastName"))),AttrAlias(Name("A_empName"))),
 						      NamedAttribute(RelAliasAttribute(RelAlias(Name("R_mang")),Attribute(Name("manageName"))),AttrAlias(Name("A_manageName"))))),
-				    TableList(Set(InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_emp")))))),
+				    TableList(AddOrderedSet(InnerJoin(AliasedResource(Relation(Name("Employee")),RelAlias(Name("R_emp")))))),
 				    None)),
 			     RelAlias(Name("R_mang"))),
 					 RelationalExpressionEq(RelAliasAttribute(RelAlias(Name("R_mang")),Attribute(Name("emp"))),