diff --git a/src/java/boa/aggregators/GraphAggregator.java b/src/java/boa/aggregators/GraphAggregator.java
index ac2b66d3d..81ddbb52e 100644
--- a/src/java/boa/aggregators/GraphAggregator.java
+++ b/src/java/boa/aggregators/GraphAggregator.java
@@ -40,7 +40,7 @@ public abstract class GraphAggregator extends Aggregator {
 	public void start(final EmitKey key) {
 		super.start(key);
 
-		this.neighbors = new HashSet<String>();
+		this.neighbors = new LinkedHashSet<String>();
 		this.weights = new HashMap<String, String>();
 	}
 
diff --git a/src/java/boa/aggregators/PreconditionAggregator.java b/src/java/boa/aggregators/PreconditionAggregator.java
index 7cf35153a..10156a9f3 100644
--- a/src/java/boa/aggregators/PreconditionAggregator.java
+++ b/src/java/boa/aggregators/PreconditionAggregator.java
@@ -21,7 +21,7 @@
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.HashMap;
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -43,7 +43,7 @@ public class PreconditionAggregator extends Aggregator {
 	private final double sigma;
 	private int args = 0;
 
-	private final Set<Expression> preconds = new HashSet<Expression>();
+	private final Set<Expression> preconds = new LinkedHashSet<Expression>();
 	private final Map<Expression, Set<String>> omega = new HashMap<Expression, Set<String>>();  // preconditions: set of methods
 
 	/**
@@ -79,7 +79,7 @@ public void aggregate(final String data, final String metadata) throws IOExcepti
 		final Expression precondition = parseexpression(precond);
 
 		if (!omega.containsKey(precondition)) {
-			omega.put(precondition, new HashSet<String>());
+			omega.put(precondition, new LinkedHashSet<String>());
 			preconds.add(precondition);
 		}
 
@@ -106,7 +106,7 @@ public void finish() throws IOException, InterruptedException {
 	 * @return map of all preconditions which include inferred preconditions
 	 */
 	private void inferNonStrictInequalities() {
-		final Set<Expression> added = new HashSet<Expression>();
+		final Set<Expression> added = new LinkedHashSet<Expression>();
 
 		for (final Expression p : preconds) {
 			if (p.getKind() == ExpressionKind.EQ) {
@@ -123,7 +123,7 @@ private void inferNonStrictInequalities() {
 							final Expression t = builder.build();
 
 							if (!preconds.contains(t)) {
-								omega.put(t, new HashSet<String>());
+								omega.put(t, new LinkedHashSet<String>());
 								added.add(t);
 							}
 
@@ -186,7 +186,7 @@ private Map<String, Double> doFiltering() {
 		// generate psi from omega
 		final Map<Expression, Set<String>> psi = new HashMap<Expression, Set<String>>();
 		for (final Expression e : preconds) {
-			psi.put(e, new HashSet<String>());
+			psi.put(e, new LinkedHashSet<String>());
 
 			for (final String s : omega.get(e)) {
 				psi.get(e).add(s.split(":", 2)[0]);
@@ -213,7 +213,7 @@ private Map<String, Double> doFiltering() {
 	private Map<Expression, Double> calcConfidence(final Map<Expression, Set<String>> precondMP) {
 		final Map<Expression, Double> precondConf = new HashMap<Expression, Double>();
 
-		final Set<String> totalCalls = new HashSet<String>();
+		final Set<String> totalCalls = new LinkedHashSet<String>();
 		for (final Expression precond : preconds)
 			totalCalls.addAll(precondMP.get(precond));
 
@@ -267,7 +267,7 @@ private List<Map.Entry<String, Double>> doRanking(final Map<String, Double> filt
 	 * @return set of all combinations of arguments
 	 */
 	private Set<SortedSet<String>> generateCombinations() {
-		final Set<SortedSet<String>> comb = new HashSet<SortedSet<String>>();
+		final Set<SortedSet<String>> comb = new LinkedHashSet<SortedSet<String>>();
 		final List<String> argList = new ArrayList<String>();
 		comb.add(new TreeSet<String>(Collections.singletonList("$RECEIVER$")));
 		argList.add("$RECEIVER$");
@@ -278,7 +278,7 @@ private Set<SortedSet<String>> generateCombinations() {
 		}
 
 		for (final String arg : argList) {
-			final Set<SortedSet<String>> tempComb = new HashSet<SortedSet<String>>(comb);
+			final Set<SortedSet<String>> tempComb = new LinkedHashSet<SortedSet<String>>(comb);
 			for (final SortedSet<String> s : tempComb) {
 				final SortedSet<String> t = new TreeSet<String>(s);
 				t.add(arg);
diff --git a/src/java/boa/aggregators/SetAggregator.java b/src/java/boa/aggregators/SetAggregator.java
index 6eeb1a49f..00e865a0d 100644
--- a/src/java/boa/aggregators/SetAggregator.java
+++ b/src/java/boa/aggregators/SetAggregator.java
@@ -17,7 +17,11 @@
 package boa.aggregators;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
 
 import boa.io.EmitKey;
 
@@ -28,7 +32,7 @@
  */
 @AggregatorSpec(name = "set", canCombine = true)
 public class SetAggregator extends Aggregator {
-	private HashSet<String> set;
+	private Set<String> set;
 	private final long max;
 
 	/**
@@ -75,7 +79,9 @@ public void aggregate(final String data, final String metadata) throws IOExcepti
 	/** {@inheritDoc} */
 	@Override
 	public void finish() throws IOException, InterruptedException {
-		for (final String s : this.set)
+		final List<String> list = new ArrayList<String>(this.set);
+		Collections.sort(list);
+		for (final String s : list)
 			this.collect(s);
 	}
 }
diff --git a/src/java/boa/compiler/SymbolTable.java b/src/java/boa/compiler/SymbolTable.java
index 42d8817d7..b4723512a 100644
--- a/src/java/boa/compiler/SymbolTable.java
+++ b/src/java/boa/compiler/SymbolTable.java
@@ -55,6 +55,7 @@ public class SymbolTable {
 	private Operand operand;
 	private Stack<BoaType> operandType = new Stack<BoaType>();
 	private boolean needsBoxing;
+	private boolean needsCast;
 	private Stack<Boolean> isVisitor = new Stack<Boolean>();
 	private Stack<VisitStatement> lastVisit = new Stack<VisitStatement>();
 	private boolean isTraverse = false;
@@ -207,7 +208,7 @@ public class SymbolTable {
 
 		// clone functions
 		globalFunctions.addFunction("clone", new BoaFunction(new BoaMap(new BoaTypeVar("K"), new BoaTypeVar("V")), new BoaType[] {new BoaMap(new BoaTypeVar("K"), new BoaTypeVar("V"))}, "(java.util.HashMap)${0}.clone()"));
-		globalFunctions.addFunction("clone", new BoaFunction(new BoaSet(new BoaTypeVar("V")), new BoaType[] {new BoaSet(new BoaTypeVar("V"))}, "(java.util.HashSet)${0}.clone()"));
+		globalFunctions.addFunction("clone", new BoaFunction(new BoaSet(new BoaTypeVar("V")), new BoaType[] {new BoaSet(new BoaTypeVar("V"))}, "(java.util.LinkedHashSet)${0}.clone()"));
 		globalFunctions.addFunction("clone", new BoaFunction(new BoaString(), new BoaType[] {new BoaString()}, "new String(${0})"));
 
 		// visitors
@@ -250,7 +251,7 @@ public class SymbolTable {
 		globalFunctions.addFunction("remove", new BoaFunction(new BoaAny(), new BoaType[] { new BoaSet(new BoaTypeVar("V")), new BoaTypeVar("V") }, "${0}.remove(${1})"));
 		globalFunctions.addFunction("clear", new BoaFunction(new BoaAny(), new BoaType[] { new BoaSet(new BoaTypeVar("V")) }, "${0}.clear()"));
 		globalFunctions.addFunction("values", new BoaFunction(new BoaArray(new BoaTypeVar("V")), new BoaType[] { new BoaSet(new BoaTypeVar("V")) }, "boa.functions.BoaIntrinsics.basic_array(${0}.toArray(new ${V}[0]))"));
-		globalFunctions.addFunction("values", new BoaFunction(new BoaArray(new BoaSet(new BoaString())), new BoaType[] { new BoaSet(new BoaSet(new BoaString())) }, "boa.functions.BoaIntrinsics.basic_array(${0}.toArray(new java.util.HashSet[0]))"));
+		globalFunctions.addFunction("values", new BoaFunction(new BoaArray(new BoaSet(new BoaString())), new BoaType[] { new BoaSet(new BoaSet(new BoaString())) }, "boa.functions.BoaIntrinsics.basic_array(${0}.toArray(new java.util.LinkedHashSet[0]))"));
 
 		globalFunctions.addFunction("union", new BoaFunction(new BoaSet(new BoaTypeVar("V")), new BoaType[] { new BoaSet(new BoaTypeVar("V")), new BoaSet(new BoaTypeVar("V")) }, "boa.functions.BoaIntrinsics.set_union(${0}, ${1})"));
 		globalFunctions.addFunction("intersect", new BoaFunction(new BoaSet(new BoaTypeVar("V")), new BoaType[] { new BoaSet(new BoaTypeVar("V")), new BoaSet(new BoaTypeVar("V")) }, "boa.functions.BoaIntrinsics.set_intersect(${0}, ${1})"));
@@ -701,6 +702,14 @@ public boolean getNeedsBoxing() {
 		return this.needsBoxing;
 	}
 
+	public void setNeedsCast(final boolean needsCast) {
+		this.needsCast = needsCast;
+	}
+
+	public boolean getNeedsCast() {
+		return this.needsCast;
+	}
+
 	public void setIsTraverse(final boolean isTraverse) {
 		this.isTraverse = isTraverse;
 	}
diff --git a/src/java/boa/compiler/transforms/InheritedAttributeTransformer.java b/src/java/boa/compiler/transforms/InheritedAttributeTransformer.java
index 730ddf9a8..037ae55dd 100644
--- a/src/java/boa/compiler/transforms/InheritedAttributeTransformer.java
+++ b/src/java/boa/compiler/transforms/InheritedAttributeTransformer.java
@@ -20,7 +20,7 @@
 
 import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -104,7 +104,7 @@ public void visit(final VisitorExpression n) {
 	 * mapping from each type T found to a list of all uses in current(T).
 	 */
 	private class FindCurrentInVisitors extends AbstractVisitorNoArgNoRet{
-		protected final Set<BoaTuple> currents = new HashSet<BoaTuple>();
+		protected final Set<BoaTuple> currents = new LinkedHashSet<BoaTuple>();
 		protected final Map<BoaTuple, List<Factor>> factorMap = new HashMap<BoaTuple, List<Factor>>();
 
 		/** @{inheritDoc} */
diff --git a/src/java/boa/compiler/transforms/VisitorOptimizingTransformer.java b/src/java/boa/compiler/transforms/VisitorOptimizingTransformer.java
index 21c17ffeb..1c8166fae 100644
--- a/src/java/boa/compiler/transforms/VisitorOptimizingTransformer.java
+++ b/src/java/boa/compiler/transforms/VisitorOptimizingTransformer.java
@@ -17,7 +17,7 @@
  */
 package boa.compiler.transforms;
 
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.Set;
 import java.util.Stack;
 
@@ -41,8 +41,8 @@
  * @author rdyer
  */
 public class VisitorOptimizingTransformer extends AbstractVisitorNoArgNoRet {
-	protected final static Set<Class<? extends BoaType>> astTypes = new HashSet<Class<? extends BoaType>>();
-	protected final static Set<Class<? extends BoaType>> revTypes = new HashSet<Class<? extends BoaType>>();
+	protected final static Set<Class<? extends BoaType>> astTypes = new LinkedHashSet<Class<? extends BoaType>>();
+	protected final static Set<Class<? extends BoaType>> revTypes = new LinkedHashSet<Class<? extends BoaType>>();
 
 	static {
 		astTypes.addAll(new ASTRootProtoTuple().reachableTypes());
@@ -70,7 +70,7 @@ public class VisitorOptimizingTransformer extends AbstractVisitorNoArgNoRet {
 	/** {@inheritDoc} */
 	@Override
 	protected void initialize() {
-		types = new HashSet<Class<? extends BoaType>>();
+		types = new LinkedHashSet<Class<? extends BoaType>>();
 		beforeChangedFile = afterChangedFile = null;
 		beforeCodeRepository = afterCodeRepository = null;
 
@@ -90,15 +90,15 @@ public void visit(final VisitorExpression n) {
 		beforeCodeRepositoryStack.push(beforeCodeRepository);
 		afterCodeRepositoryStack.push(afterCodeRepository);
 
-		types = new HashSet<Class<? extends BoaType>>();
+		types = new LinkedHashSet<Class<? extends BoaType>>();
 		beforeChangedFile = afterChangedFile = null;
 
 		n.getBody().accept(this);
 
 		// if the visitor doesnt use an AST type, we can enforce
 		// a stop at the lowest level visited
-		final Set<Class<? extends BoaType>> hasAst = new HashSet<Class<? extends BoaType>>(types);
-		final Set<Class<? extends BoaType>> hasRevision = new HashSet<Class<? extends BoaType>>(types);
+		final Set<Class<? extends BoaType>> hasAst = new LinkedHashSet<Class<? extends BoaType>>(types);
+		final Set<Class<? extends BoaType>> hasRevision = new LinkedHashSet<Class<? extends BoaType>>(types);
 		hasAst.retainAll(astTypes);
 		hasRevision.retainAll(revTypes);
 		if (hasRevision.isEmpty()) {
diff --git a/src/java/boa/compiler/visitors/CodeGeneratingVisitor.java b/src/java/boa/compiler/visitors/CodeGeneratingVisitor.java
index a2231da06..f9a35ded3 100644
--- a/src/java/boa/compiler/visitors/CodeGeneratingVisitor.java
+++ b/src/java/boa/compiler/visitors/CodeGeneratingVisitor.java
@@ -185,7 +185,7 @@ public void visit(final VarDeclStatement n) {
 			final ST st = stg.getInstanceOf("VarDecl");
 
 			st.add("id", n.getId().getToken());
-			st.add("type", n.type.toJavaType());
+			st.add("type", n.type.toInterfaceJavaType());
 
 			if (n.isStatic())
 				st.add("isstatic", true);
@@ -200,7 +200,7 @@ public void visit(final VarDeclStatement n) {
 	 * @author rdyer
 	 */
 	protected class FunctionDeclaratorCodeGeneratingVisitor extends AbstractCodeGeneratingVisitor {
-		protected final Set<String> funcs = new HashSet<String>();
+		protected final Set<String> funcs = new LinkedHashSet<String>();
 
 		/** {@inheritDoc} */
 		@Override
@@ -230,7 +230,7 @@ public void visit(final FunctionType n) {
 
 			for (final Component c : params) {
 				args.add(c.getIdentifier().getToken());
-				types.add(c.getType().type.toJavaType());
+				types.add(c.getType().type.toInterfaceJavaType());
 			}
 
 			st.add("name", funcType.toJavaType());
@@ -251,7 +251,7 @@ public void visit(final FunctionType n) {
 	 * @author ankuraga
 	 */
 	protected class TupleDeclaratorCodeGeneratingVisitor extends AbstractCodeGeneratingVisitor {
-		protected final Set<String> tuples = new HashSet<String>();
+		protected final Set<String> tuples = new LinkedHashSet<String>();
 
 		/** {@inheritDoc} */
 		@Override
@@ -275,17 +275,23 @@ public void visit(final Composite n) {
 
 				final List<String> fields = new ArrayList<String>();
 				final List<String> types = new ArrayList<String>();
+				final List<String> types2 = new ArrayList<String>();
+				final List<Boolean> aliases = new ArrayList<Boolean>();
 
 				int counter = 0;
 				for (final Expression e : n.getExprs()) {
 					fields.add("f" + counter);
-					types.add(e.type.toBoxedJavaType());
+					types.add(e.type.toInterfaceJavaType());
+					types2.add(e.type.toBoxedJavaType());
+					aliases.add((e.type instanceof BoaProtoTuple) || (e.type instanceof BoaEnum));
 					counter++;
 				}
 
 				st.add("name", name);
 				st.add("fields", fields);
 				st.add("types", types);
+				st.add("types2", types2);
+				st.add("aliases", aliases);
 
 				code.add(st.render());
 			}
@@ -306,27 +312,29 @@ public void visit(final TupleType n) {
 
 			final BoaTuple tupType = ((BoaTuple) n.type);
 
-			final List<Component> members = n.getMembers();
 			final List<String> fields = new ArrayList<String>();
 			final List<String> types = new ArrayList<String>();
+			final List<String> types2 = new ArrayList<String>();
 			final List<Boolean> aliases = new ArrayList<Boolean>();
 
 			int fieldCount = 0;
-			for (final Component c : members) {
+			for (final Component c : n.getMembers()) {
 				if (c.hasIdentifier()) {
 					fields.add(c.getIdentifier().getToken());
 				} else {
 					fields.add("f" + fieldCount);
 				}
 				fieldCount++;
-				BoaType type = c.getType().type;
+				final BoaType type = c.getType().type;
 				aliases.add((type instanceof BoaProtoTuple) || (type instanceof BoaEnum));
-				types.add(type.toBoxedJavaType());
+				types.add(type.toInterfaceJavaType());
+				types2.add(type.toBoxedJavaType());
 			}
 
 			st.add("name", tupType.toJavaType());
 			st.add("fields", fields);
 			st.add("types", types);
+			st.add("types2", types2);
 			st.add("aliases", aliases);
 
 			code.add(st.render());
@@ -427,7 +435,7 @@ protected class IndexeeFindingVisitor extends AbstractVisitorNoReturn<String> {
 		protected Node lastFactor;
 
 		protected Map<Node, Node> lastFactors = new HashMap<Node, Node>();
-		protected final Set<Node> indexees = new HashSet<Node>();
+		protected final Set<Node> indexees = new LinkedHashSet<Node>();
 
 		/** {@inheritDoc} */
 		@Override
@@ -728,15 +736,18 @@ public void visit(final Composite n) {
 				return;
 			}
 
+			n.env.setNeedsCast(true);
 			visit(n.getExprs());
+			n.env.setNeedsCast(false);
+			st.add("exprlist", code.removeLast());
 
-			if (t instanceof BoaArray && ((BoaArray)t).getType() instanceof BoaEnum) {
+			if (t instanceof BoaArray && ((BoaArray)t).getType() instanceof BoaScalar) {
+				st.add("type", t.toBoxedJavaType());
+			} else if (t instanceof BoaArray && ((BoaArray)t).getType() instanceof BoaEnum) {
 				st.add("type", "Object[] ");
 			} else {
 				st.add("type", t.toJavaType().replaceAll("<(.*)>", ""));
 			}
-
-			st.add("exprlist", code.removeLast());
 		}
 
 		code.add(st.render());
@@ -784,32 +795,35 @@ public void visit(final Conjunction n) {
 	/** {@inheritDoc} */
 	@Override
 	public void visit(final Factor n) {
+		String s = "";
+
 		if (n.getOpsSize() > 0) {
 			n.env.setOperand(n.getOperand());
 
-			String accept = "";
 			abortGeneration = false;
 
 			if (!(n.getOp(0) instanceof Call)) {
 				n.getOperand().accept(this);
 				n.env.setOperandType(n.getOperand().type);
-				accept = code.removeLast();
+				s = code.removeLast();
 			}
 
 			for (int i = 0; !abortGeneration && i < n.getOpsSize(); i++) {
 				final Node o = n.getOp(i);
 
 				o.accept(this);
-				accept += code.removeLast();
+				s += code.removeLast();
 			}
 
 			n.env.getOperandType();
-
-			code.add(accept);
 		} else {
 			n.getOperand().accept(this);
-			code.add(code.removeLast());
+			s = code.removeLast();
 		}
+
+		if (n.env != null && n.env.getNeedsCast())
+			s = "((" + n.type.toJavaType() + ")" + s + ")";
+		code.add(s);
 	}
 
 	/** {@inheritDoc} */
@@ -860,7 +874,7 @@ public void visit(final Index n) {
 		final BoaType indexType = n.getStart().type;
 		n.getStart().accept(this);
 		if (indexType instanceof BoaInt && !(t instanceof BoaMap))
-			st.add("index", "(int)(" + code.removeLast() + ")");
+			st.add("index", "(int)((long)" + code.removeLast() + ")");
 		else
 			st.add("index", code.removeLast());
 
@@ -1494,7 +1508,7 @@ public void visit(final TraverseStatement n) {
 		cfgBuilder.start(n);
 		new CreateNodeId().start(cfgBuilder);
 
-		final HashSet<Identifier> aliastSet = new LocalMayAliasAnalysis().start(cfgBuilder, traversalId);
+		final Set<Identifier> aliastSet = new LocalMayAliasAnalysis().start(cfgBuilder, traversalId);
 
 		final DataFlowSensitivityAnalysis dataFlowSensitivityAnalysis = new DataFlowSensitivityAnalysis();
 		dataFlowSensitivityAnalysis.start(cfgBuilder, aliastSet);
@@ -1573,7 +1587,7 @@ public void visit(final FunctionExpression n) {
 			if (!(c instanceof BoaName))
 				continue;
 			args.add(((BoaName)c).getId());
-			types.add(((BoaName)c).getType().toJavaType());
+			types.add(((BoaName)c).getType().toInterfaceJavaType());
 		}
 
 		this.varDecl.start(n);
@@ -1800,7 +1814,7 @@ public void visit(final FunctionType n) {
 
 		for (int i = 0; i < paramTypes.length; i++) {
 			args.add(((BoaName) paramTypes[i]).getId());
-			types.add(paramTypes[i].toJavaType());
+			types.add(paramTypes[i].toInterfaceJavaType());
 		}
 
 		st.add("name", funcType.toJavaType());
@@ -1823,19 +1837,7 @@ public void visit(final FixPType n) {
 	/** {@inheritDoc} */
 	@Override
 	public void visit(final MapType n) {
-		final ST st = stg.getInstanceOf("MapType");
-
-		n.env.setNeedsBoxing(true);
-
-		n.getIndex().accept(this);
-		st.add("key", code.removeLast());
-
-		n.getValue().accept(this);
-		st.add("value", code.removeLast());
-
-		n.env.setNeedsBoxing(false);
-
-		code.add(st.render());
+		code.add(n.type.toJavaType());
 	}
 
 	/** {@inheritDoc} */
@@ -1860,46 +1862,19 @@ public void visit(final OutputType n) {
 	/** {@inheritDoc} */
 	@Override
 	public void visit(final StackType n) {
-		final ST st = stg.getInstanceOf("StackType");
-
-		n.env.setNeedsBoxing(true);
-
-		n.getValue().accept(this);
-		st.add("value", code.removeLast());
-
-		n.env.setNeedsBoxing(false);
-
-		code.add(st.render());
+		code.add(n.type.toJavaType());
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void visit(final QueueType n) {
-		final ST st = stg.getInstanceOf("QueueType");
-
-		n.env.setNeedsBoxing(true);
-
-		n.getValue().accept(this);
-		st.add("value", code.removeLast());
-
-		n.env.setNeedsBoxing(false);
-
-		code.add(st.render());
+		code.add(n.type.toJavaType());
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void visit(final SetType n) {
-		final ST st = stg.getInstanceOf("SetType");
-
-		n.env.setNeedsBoxing(true);
-
-		n.getValue().accept(this);
-		st.add("value", code.removeLast());
-
-		n.env.setNeedsBoxing(false);
-
-		code.add(st.render());
+		code.add(n.type.toJavaType());
 	}
 
 	/** {@inheritDoc} */
diff --git a/src/java/boa/compiler/visitors/IdentifierFindingVisitor.java b/src/java/boa/compiler/visitors/IdentifierFindingVisitor.java
index 7502b79d0..4dcded4c8 100644
--- a/src/java/boa/compiler/visitors/IdentifierFindingVisitor.java
+++ b/src/java/boa/compiler/visitors/IdentifierFindingVisitor.java
@@ -17,7 +17,7 @@
  */
 package boa.compiler.visitors;
 
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.Set;
 
 import boa.compiler.ast.Identifier;
@@ -27,7 +27,7 @@
  * @author rdyer
  */
 public class IdentifierFindingVisitor extends AbstractVisitorNoArgNoRet {
-	protected final Set<String> names = new HashSet<String>();
+	protected final Set<String> names = new LinkedHashSet<String>();
 
 	public Set<String> getNames() {
 		return names;
diff --git a/src/java/boa/compiler/visitors/TaskClassifyingVisitor.java b/src/java/boa/compiler/visitors/TaskClassifyingVisitor.java
index 07fd29341..a0205646a 100644
--- a/src/java/boa/compiler/visitors/TaskClassifyingVisitor.java
+++ b/src/java/boa/compiler/visitors/TaskClassifyingVisitor.java
@@ -16,7 +16,7 @@
  */
 package boa.compiler.visitors;
 
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.Set;
 
 import boa.compiler.ast.Call;
@@ -34,13 +34,13 @@
  * @author rdyer
  */
 public class TaskClassifyingVisitor extends AbstractVisitorNoArgNoRet {
-	protected final static Set<Class<? extends BoaType>> astTypes = new HashSet<Class<? extends BoaType>>();
+	protected final static Set<Class<? extends BoaType>> astTypes = new LinkedHashSet<Class<? extends BoaType>>();
 
 	static {
 		astTypes.addAll(new ASTRootProtoTuple().reachableTypes());
 	}
 
-	protected final Set<Class<? extends BoaType>> types = new HashSet<Class<? extends BoaType>>();
+	protected final Set<Class<? extends BoaType>> types = new LinkedHashSet<Class<? extends BoaType>>();
 
 	private boolean complex = false;
 
diff --git a/src/java/boa/compiler/visitors/TypeCheckingVisitor.java b/src/java/boa/compiler/visitors/TypeCheckingVisitor.java
index b121f8a42..a80331a36 100644
--- a/src/java/boa/compiler/visitors/TypeCheckingVisitor.java
+++ b/src/java/boa/compiler/visitors/TypeCheckingVisitor.java
@@ -54,8 +54,8 @@ public class TypeCheckingVisitor extends AbstractVisitorNoReturn<SymbolTable> {
 	 * @author rdyer
 	 */
 	protected class VisitorCheckingVisitor extends AbstractVisitorNoArgNoRet {
-		protected Set<String> befores = new HashSet<String>();
-		protected Set<String> afters = new HashSet<String>();
+		protected Set<String> befores = new LinkedHashSet<String>();
+		protected Set<String> afters = new LinkedHashSet<String>();
 		protected boolean nested = false;
 
 		/** {@inheritDoc} */
@@ -99,7 +99,7 @@ public void visit(final VisitStatement n) {
 	}
 
 	protected class TraversalCheckingVisitor extends AbstractVisitorNoArgNoRet {
-		protected Set<String> befores = new HashSet<String>();
+		protected Set<String> befores = new LinkedHashSet<String>();
 		protected boolean nested = false;
 
 		/** {@inheritDoc} */
@@ -141,7 +141,7 @@ public void visit(final TraverseStatement n) {
 	}
 
 	protected class FixPCheckingVisitor extends AbstractVisitorNoArgNoRet {
-		protected Set<String> befores = new HashSet<String>();
+		protected Set<String> befores = new LinkedHashSet<String>();
 		protected boolean nested = false;
 
 		/** {@inheritDoc} */
diff --git a/src/java/boa/compiler/visitors/analysis/CreateNodeId.java b/src/java/boa/compiler/visitors/analysis/CreateNodeId.java
index 9fc5c3361..f5249d1eb 100644
--- a/src/java/boa/compiler/visitors/analysis/CreateNodeId.java
+++ b/src/java/boa/compiler/visitors/analysis/CreateNodeId.java
@@ -36,7 +36,7 @@ public final void createNodeIds(final Node node, final java.util.Set<Node> visit
 	}
 
 	public void start(final CFGBuildingVisitor cfgBuilder) {
-		final java.util.Set<Node> visitedNodes = new java.util.HashSet<Node>();
+		final java.util.Set<Node> visitedNodes = new java.util.LinkedHashSet<Node>();
 		for (final Node n : cfgBuilder.currentStartNodes)
 			createNodeIds(n, visitedNodes);
 	}
diff --git a/src/java/boa/compiler/visitors/analysis/DataFlowSensitivityAnalysis.java b/src/java/boa/compiler/visitors/analysis/DataFlowSensitivityAnalysis.java
index a2a063d15..a916b040d 100644
--- a/src/java/boa/compiler/visitors/analysis/DataFlowSensitivityAnalysis.java
+++ b/src/java/boa/compiler/visitors/analysis/DataFlowSensitivityAnalysis.java
@@ -16,8 +16,9 @@
  */
 package boa.compiler.visitors.analysis;
 
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Set;
 
 import boa.compiler.ast.Call;
 import boa.compiler.ast.Factor;
@@ -33,7 +34,7 @@
  */
 public class DataFlowSensitivityAnalysis extends AbstractVisitorNoArgNoRet {
 	public boolean getValueFound = false;
-	public HashSet<Identifier> getValueNodes = new HashSet<Identifier>();
+	public Set<Identifier> getValueNodes = new LinkedHashSet<Identifier>();
 	boolean flowSensitive = false;
 	boolean argFlag = false;
 	protected boolean abortGeneration = false;
@@ -44,8 +45,8 @@ public boolean isFlowSensitive() {
 		return flowSensitive;
 	}
 
-	public void start(final CFGBuildingVisitor cfgBuilder, final HashSet<Identifier> aliastSet) {
-		final java.util.Set<Integer> visitedNodes = new java.util.HashSet<Integer>();
+	public void start(final CFGBuildingVisitor cfgBuilder, final Set<Identifier> aliastSet) {
+		final Set<Integer> visitedNodes = new LinkedHashSet<Integer>();
 		visitedNodes.add(cfgBuilder.currentStartNodes.get(0).nodeId);
 		dfs(cfgBuilder.currentStartNodes.get(0), visitedNodes);
 
diff --git a/src/java/boa/compiler/visitors/analysis/InformationAnalysis.java b/src/java/boa/compiler/visitors/analysis/InformationAnalysis.java
index f142e9ad1..12aadb46e 100644
--- a/src/java/boa/compiler/visitors/analysis/InformationAnalysis.java
+++ b/src/java/boa/compiler/visitors/analysis/InformationAnalysis.java
@@ -16,8 +16,9 @@
  */
 package boa.compiler.visitors.analysis;
 
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Set;
 
 import boa.compiler.ast.Call;
 import boa.compiler.ast.Factor;
@@ -37,21 +38,21 @@ public class InformationAnalysis extends AbstractVisitorNoArgNoRet {
 	public boolean intersectionFound = false;
 	public boolean addFound = false;
 	public boolean removeFound = false;
-	public HashSet<Identifier> getValueNodesAlias = new HashSet<Identifier>();
-	public HashSet<Identifier> totalGetValueNodes = new HashSet<Identifier>();
+	public Set<Identifier> getValueNodesAlias = new LinkedHashSet<Identifier>();
+	public Set<Identifier> totalGetValueNodes = new LinkedHashSet<Identifier>();
 	protected final IdentifierFindingVisitor idFinder = new IdentifierFindingVisitor();
 	protected final CallFindingVisitor callFinder = new CallFindingVisitor();
 	protected boolean abortGeneration = false;
 	public boolean argFlag = false;
 	public boolean genFlag = false;
 	public boolean killFlag = false;
-	HashSet<String> mergeOperation = new HashSet<String>(); 
+	Set<String> mergeOperation = new LinkedHashSet<String>(); 
 	int satisfiedNodes = 0;
 
-	public void start(final CFGBuildingVisitor cfgBuilder, final HashSet<Identifier> getValueNodesAlias, final HashSet<Identifier> totalGetValueNodes) {
+	public void start(final CFGBuildingVisitor cfgBuilder, final Set<Identifier> getValueNodesAlias, final Set<Identifier> totalGetValueNodes) {
 		this.getValueNodesAlias = getValueNodesAlias;
 		this.totalGetValueNodes = totalGetValueNodes;
-		final java.util.Set<Integer> visitedNodes = new java.util.HashSet<Integer>();
+		final Set<Integer> visitedNodes = new LinkedHashSet<Integer>();
 		visitedNodes.add(cfgBuilder.currentStartNodes.get(0).nodeId);
 		dfs(cfgBuilder.currentStartNodes.get(0), visitedNodes);
 	}
diff --git a/src/java/boa/compiler/visitors/analysis/LocalMayAliasAnalysis.java b/src/java/boa/compiler/visitors/analysis/LocalMayAliasAnalysis.java
index b9a3db12e..358c6dca2 100644
--- a/src/java/boa/compiler/visitors/analysis/LocalMayAliasAnalysis.java
+++ b/src/java/boa/compiler/visitors/analysis/LocalMayAliasAnalysis.java
@@ -16,8 +16,9 @@
  */
 package boa.compiler.visitors.analysis;
 
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Set;
 
 import boa.compiler.ast.Call;
 import boa.compiler.ast.Conjunction;
@@ -35,15 +36,15 @@
  * @author rramu
  */
 public class LocalMayAliasAnalysis extends AbstractVisitorNoArgNoRet {
-	HashSet<Identifier> aliastSet = new HashSet<Identifier>();
+	Set<Identifier> aliastSet = new LinkedHashSet<Identifier>();
 	Identifier lastDefVariable;
 	boolean cloneFound = false;
 	protected final IdentifierFindingVisitor idFinder = new IdentifierFindingVisitor();
 	protected final CallFindingVisitor callFinder = new CallFindingVisitor();
 
-	public HashSet<Identifier> start(CFGBuildingVisitor cfgBuilder, Identifier id) {
+	public Set<Identifier> start(CFGBuildingVisitor cfgBuilder, Identifier id) {
 		aliastSet.add(id);
-		final java.util.Set<Integer> visitedNodes = new java.util.HashSet<Integer>();
+		final Set<Integer> visitedNodes = new LinkedHashSet<Integer>();
 		visitedNodes.add(cfgBuilder.currentStartNodes.get(0).nodeId);
 		dfs(cfgBuilder.currentStartNodes.get(0), visitedNodes);
 		return aliastSet;
diff --git a/src/java/boa/compiler/visitors/analysis/LoopSensitivityAnalysis.java b/src/java/boa/compiler/visitors/analysis/LoopSensitivityAnalysis.java
index 87a2e3fc4..9234524cc 100644
--- a/src/java/boa/compiler/visitors/analysis/LoopSensitivityAnalysis.java
+++ b/src/java/boa/compiler/visitors/analysis/LoopSensitivityAnalysis.java
@@ -16,8 +16,9 @@
  */
 package boa.compiler.visitors.analysis;
 
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Set;
 
 import boa.compiler.ast.Call;
 import boa.compiler.ast.Factor;
@@ -36,15 +37,15 @@
 public class LoopSensitivityAnalysis extends AbstractVisitorNoArgNoRet {
 	public CFGBuildingVisitor cfgBuilder;
 	public boolean getValueFound = false;
-	public HashSet<Identifier> getValueNodes = new HashSet<Identifier>();
-	public HashSet<Identifier> totalGetValueNodes = new HashSet<Identifier>();
-	public HashSet<Identifier> getValueNodesAlias = new HashSet<Identifier>();
+	public Set<Identifier> getValueNodes = new LinkedHashSet<Identifier>();
+	public Set<Identifier> totalGetValueNodes = new LinkedHashSet<Identifier>();
+	public Set<Identifier> getValueNodesAlias = new LinkedHashSet<Identifier>();
 	boolean loopSensitive = false;
 	protected final IdentifierFindingVisitor idFinder = new IdentifierFindingVisitor();
 	protected final CallFindingVisitor callFinder = new CallFindingVisitor();
 	protected boolean abortGeneration = false;
 	public boolean argFlag = false;
-	public HashSet<Identifier> aliastSet;
+	public Set<Identifier> aliastSet;
 	public Identifier lastDeclVariable;
 	boolean isRhs = false;
 
@@ -52,16 +53,16 @@ public boolean isLoopSensitive() {
 		return loopSensitive;
 	}
 
-	public void start(CFGBuildingVisitor cfgBuilder, HashSet<Identifier> aliastSet) {
+	public void start(CFGBuildingVisitor cfgBuilder, Set<Identifier> aliastSet) {
 		this.aliastSet = aliastSet;
 		this.cfgBuilder = cfgBuilder;
-		final java.util.Set<Integer> visitedNodes = new java.util.HashSet<Integer>();
+		final Set<Integer> visitedNodes = new LinkedHashSet<Integer>();
 		visitedNodes.add(cfgBuilder.currentStartNodes.get(0).nodeId);
 		dfs(cfgBuilder.currentStartNodes.get(0), visitedNodes);
 
 		for (final Identifier getValueNode : getValueNodes) {
 			final LocalMayAliasAnalysis localMayAliasAnalysis = new LocalMayAliasAnalysis();
-			final HashSet<Identifier> tmpAliastSet = localMayAliasAnalysis.start(this.cfgBuilder, getValueNode);
+			final Set<Identifier> tmpAliastSet = localMayAliasAnalysis.start(this.cfgBuilder, getValueNode);
 			getValueNodesAlias.addAll(tmpAliastSet);
 		}
 		final InformationAnalysis informationAnalysis = new InformationAnalysis();
diff --git a/src/java/boa/functions/BoaGraphIntrinsics.java b/src/java/boa/functions/BoaGraphIntrinsics.java
index 4978bfad3..e62ac70d3 100644
--- a/src/java/boa/functions/BoaGraphIntrinsics.java
+++ b/src/java/boa/functions/BoaGraphIntrinsics.java
@@ -143,8 +143,8 @@ public static PDGSlicer getpdgslice(final Method method, Long id, boolean normal
 	}
 
 	//@FunctionSpec(name = "get_nodes_with_definition", returnType = "set of string", formalParameters = { "Node" })
-	public static HashSet<String> getNodesWithDefinition(final Node node) {
-		final HashSet<String> vardef = new HashSet<String>();
+	public static Set<String> getNodesWithDefinition(final Node node) {
+		final Set<String> vardef = new LinkedHashSet<String>();
 		if (node.getExpression() != null) {
 			if (node.getExpression().getKind() == ExpressionKind.VARDECL || node.getExpression().getKind() == ExpressionKind.ASSIGN) {
 				vardef.add(String.valueOf(node.getId()));
@@ -154,8 +154,8 @@ public static HashSet<String> getNodesWithDefinition(final Node node) {
 	}
 
 	//@FunctionSpec(name = "get_variable_killed", returnType = "set of string", formalParameters = {"CFG", "Node" })
-	public static HashSet<String> getVariableKilled(final boa.types.Control.Graph cfg, final Node node) {
-		final HashSet<String> varkilled = new HashSet<String>();
+	public static Set<String> getVariableKilled(final boa.types.Control.Graph cfg, final Node node) {
+		final Set<String> varkilled = new LinkedHashSet<String>();
 		String vardef = "";
 
 		if (node.getExpression() != null) {
@@ -189,8 +189,8 @@ else if (tnode.getExpression().getKind() == ExpressionKind.ASSIGN) {
 	}
 
 	//@FunctionSpec(name = "get_variable_def", returnType = "set of string", formalParameters = { "Node" })
-	public static HashSet<String> getVariableDef(final Node node) {
-		final HashSet<String> vardef = new HashSet<String>();
+	public static Set<String> getVariableDef(final Node node) {
+		final Set<String> vardef = new LinkedHashSet<String>();
 		if (node.getExpression() != null) {
 			if (node.getExpression().getKind() == ExpressionKind.VARDECL) {
 				vardef.add(node.getExpression().getVariableDeclsList().get(0).getName());
@@ -203,15 +203,15 @@ else if (node.getExpression().getKind() == ExpressionKind.ASSIGN) {
 	}
 
 	//@FunctionSpec(name = "get_variable_used", returnType = "set of string", formalParameters = { "Node" })
-	public static HashSet<String> getVariableUsed(final Node node) {
-		final HashSet<String> varused = new HashSet<String>();
+	public static Set<String> getVariableUsed(final Node node) {
+		final Set<String> varused = new LinkedHashSet<String>();
 		if (node.getExpression() != null) {
 			traverseExpr(varused, node.getExpression());
 		}
 		return varused;
 	}
 
-	public static void traverseExpr(final HashSet<String> varused, final Expression expr) {
+	public static void traverseExpr(final Set<String> varused, final Expression expr) {
 		if (expr.getVariable() != null) {
 			varused.add(expr.getVariable());
 		}
@@ -226,7 +226,7 @@ public static void traverseExpr(final HashSet<String> varused, final Expression
 		}
 	}
 
-	public static void traverseVarDecls(final HashSet<String> varused, final Variable vardecls) {
+	public static void traverseVarDecls(final Set<String> varused, final Variable vardecls) {
 		if (vardecls.getInitializer() != null) {
 			traverseExpr(varused, vardecls.getInitializer());
 		}
diff --git a/src/java/boa/functions/BoaIntrinsics.java b/src/java/boa/functions/BoaIntrinsics.java
index aef0c4d35..e5906f71d 100644
--- a/src/java/boa/functions/BoaIntrinsics.java
+++ b/src/java/boa/functions/BoaIntrinsics.java
@@ -21,7 +21,7 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.Comparator;
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.PriorityQueue;
@@ -75,7 +75,7 @@ public static int getRevisionIndex(final CodeRepository cr, final long headId, f
 		final PriorityQueue<Integer> pq = new PriorityQueue<Integer>(1 + revCount / 4);
 		pq.offer((int)headId);
 
-		final Set<Integer> seenIds = new HashSet<Integer>();
+		final Set<Integer> seenIds = new LinkedHashSet<Integer>();
 		int idx = -1;
 		long lasttime = Long.MIN_VALUE;
 
@@ -161,10 +161,10 @@ public static ChangedFile[] getSnapshotByIndex(final CodeRepository cr, final lo
 		if (commitOffset < 0)
 			return new ChangedFile[0];
 		final List<ChangedFile> snapshot = new LinkedList<ChangedFile>();
-		final Set<String> adds = new HashSet<String>();
-		final Set<String> dels = new HashSet<String>();
+		final Set<String> adds = new LinkedHashSet<String>();
+		final Set<String> dels = new LinkedHashSet<String>();
 		final PriorityQueue<Integer> pq = new PriorityQueue<Integer>(100, snapshotComparator);
-		final Set<Integer> queuedCommitIds = new HashSet<Integer>();
+		final Set<Integer> queuedCommitIds = new LinkedHashSet<Integer>();
 		pq.offer((int) commitOffset);
 		queuedCommitIds.add((int) commitOffset);
 		while (!pq.isEmpty()) {
@@ -280,10 +280,10 @@ public static ChangedFile[] getSnapshot(final CodeRepository cr, final Revision
 	@FunctionSpec(name = "getsnapshot", returnType = "array of ChangedFile", formalParameters = { "CodeRepository", "Revision", "string..." })
 	public static ChangedFile[] getSnapshot(final CodeRepository cr, final Revision commit, final String... kinds) {
 		final List<ChangedFile> snapshot = new LinkedList<ChangedFile>();
-		final Set<String> adds = new HashSet<String>();
-		final Set<String> dels = new HashSet<String>();
+		final Set<String> adds = new LinkedHashSet<String>();
+		final Set<String> dels = new LinkedHashSet<String>();
 		final PriorityQueue<Integer> pq = new PriorityQueue<Integer>(100, snapshotComparator);
-		final Set<Integer> queuedCommitIds = new HashSet<Integer>();
+		final Set<Integer> queuedCommitIds = new LinkedHashSet<Integer>();
 		update(snapshot, commit, adds, dels, pq, queuedCommitIds, kinds);
 		while (!pq.isEmpty()) {
 			final int offset = pq.poll();
@@ -329,7 +329,7 @@ public static ChangedFile[] getPreviousVersion(final CodeRepository cr, final Ch
 				fb.setName(cf.getPreviousNames(i));
 			final ChangedFile key = fb.build();
 			int revisionIndex = cf.getPreviousVersions(i);
-			final Set<Integer> queuedRevisionIds = new HashSet<Integer>();
+			final Set<Integer> queuedRevisionIds = new LinkedHashSet<Integer>();
 			final PriorityQueue<Integer> pq = new PriorityQueue<Integer>(100, snapshotComparator);
 			pq.offer(revisionIndex);
 			queuedRevisionIds.add(revisionIndex);
@@ -487,7 +487,7 @@ public static <T> String arrayToString(final T[] arr) {
 		return s;
 	}
 
-	public static String arrayToString(final long[] arr) {
+	public static String arrayToString(final Long[] arr) {
 		String s = "";
 		for (final long val : arr)
 			if (s.isEmpty())
@@ -497,7 +497,7 @@ public static String arrayToString(final long[] arr) {
 		return s;
 	}
 
-	public static String arrayToString(final double[] arr) {
+	public static String arrayToString(final Double[] arr) {
 		String s = "";
 		for (final double val : arr)
 			if (s.isEmpty())
@@ -507,7 +507,7 @@ public static String arrayToString(final double[] arr) {
 		return s;
 	}
 
-	public static String arrayToString(final boolean[] arr) {
+	public static String arrayToString(final Boolean[] arr) {
 		String s = "";
 		for (final boolean val : arr)
 			if (s.isEmpty())
@@ -521,21 +521,21 @@ public static <T> boolean deepEquals(final T[] arr, final T[] arr2) {
 		return java.util.Arrays.deepEquals(arr, arr2);
 	}
 
-	public static boolean deepEquals(final long[] arr, final long[] arr2) {
+	public static boolean deepEquals(final Long[] arr, final Long[] arr2) {
 		if (arr.length != arr2.length) return false;
 		for (int i = 0; i < arr.length; i++)
 			if (arr2[i] != arr[i]) return false;
 		return true;
 	}
 
-	public static boolean deepEquals(final double[] arr, final double[] arr2) {
+	public static boolean deepEquals(final Double[] arr, final Double[] arr2) {
 		if (arr.length != arr2.length) return false;
 		for (int i = 0; i < arr.length; i++)
 			if (arr2[i] != arr[i]) return false;
 		return true;
 	}
 
-	public static boolean deepEquals(final boolean[] arr, final boolean[] arr2) {
+	public static boolean deepEquals(final Boolean[] arr, final Boolean[] arr2) {
 		if (arr.length != arr2.length) return false;
 		for (int i = 0; i < arr.length; i++)
 			if (arr2[i] != arr[i]) return false;
@@ -547,22 +547,22 @@ public static <T> T[] basic_array(final T[] arr) {
 		return arr;
 	}
 
-	public static <T> long[] basic_array(final Long[] arr) {
-		final long[] arr2 = new long[arr.length];
+	public static <T> Long[] basic_array(final Long[] arr) {
+		final Long[] arr2 = new Long[arr.length];
 		for (int i = 0; i < arr.length; i++)
 			arr2[i] = arr[i];
 		return arr2;
 	}
 
-	public static <T> double[] basic_array(final Double[] arr) {
-		final double[] arr2 = new double[arr.length];
+	public static <T> Double[] basic_array(final Double[] arr) {
+		final Double[] arr2 = new Double[arr.length];
 		for (int i = 0; i < arr.length; i++)
 			arr2[i] = arr[i];
 		return arr2;
 	}
 
-	public static <T> boolean[] basic_array(final Boolean[] arr) {
-		final boolean[] arr2 = new boolean[arr.length];
+	public static <T> Boolean[] basic_array(final Boolean[] arr) {
+		final Boolean[] arr2 = new Boolean[arr.length];
 		for (int i = 0; i < arr.length; i++)
 			arr2[i] = arr[i];
 		return arr2;
@@ -583,73 +583,73 @@ public static <T> T[] concat(final T[] first, final T[]... rest) {
 		return result;
 	}
 
-	public static long[] concat(final long[] first, final long[]... rest) {
+	public static Long[] concat(final Long[] first, final Long[]... rest) {
 		int totalLength = first.length;
-		for (final long[] array : rest)
+		for (final Long[] array : rest)
 			totalLength += array.length;
 
-		final long[] result = new long[totalLength];
+		final Long[] result = new Long[totalLength];
 		System.arraycopy(first, 0, result, 0, first.length);
 
 		int offset = first.length;
-		for (final long[] array : rest) {
+		for (final Long[] array : rest) {
 			System.arraycopy(array, 0, result, offset, array.length);
 			offset += array.length;
 		}
 		return result;
 	}
 
-	public static double[] concat(final double[] first, final double[]... rest) {
+	public static Double[] concat(final Double[] first, final Double[]... rest) {
 		int totalLength = first.length;
-		for (final double[] array : rest)
+		for (final Double[] array : rest)
 			totalLength += array.length;
 
-		final double[] result = new double[totalLength];
+		final Double[] result = new Double[totalLength];
 		System.arraycopy(first, 0, result, 0, first.length);
 
 		int offset = first.length;
-		for (final double[] array : rest) {
+		for (final Double[] array : rest) {
 			System.arraycopy(array, 0, result, offset, array.length);
 			offset += array.length;
 		}
 		return result;
 	}
 
-	public static boolean[] concat(final boolean[] first, final boolean[]... rest) {
+	public static Boolean[] concat(final Boolean[] first, final Boolean[]... rest) {
 		int totalLength = first.length;
-		for (final boolean[] array : rest)
+		for (final Boolean[] array : rest)
 			totalLength += array.length;
 
-		final boolean[] result = new boolean[totalLength];
+		final Boolean[] result = new Boolean[totalLength];
 		System.arraycopy(first, 0, result, 0, first.length);
 
 		int offset = first.length;
-		for (final boolean[] array : rest) {
+		for (final Boolean[] array : rest) {
 			System.arraycopy(array, 0, result, offset, array.length);
 			offset += array.length;
 		}
 		return result;
 	}
 
-	public static <T> java.util.HashSet<T> set_union(final java.util.Set<T> s1, final java.util.Set<T> s2) {
-		final java.util.HashSet<T> s = new java.util.HashSet<T>(s1);
+	public static <T> java.util.Set<T> set_union(final java.util.Set<T> s1, final java.util.Set<T> s2) {
+		final java.util.Set<T> s = new java.util.LinkedHashSet<T>(s1);
 		s.addAll(s2);
 		return s;
 	}
 
-	public static <T> java.util.HashSet<T> set_intersect(final java.util.Set<T> s1, final java.util.Set<T> s2) {
-		final java.util.HashSet<T> s = new java.util.HashSet<T>(s1);
+	public static <T> java.util.Set<T> set_intersect(final java.util.Set<T> s1, final java.util.Set<T> s2) {
+		final java.util.Set<T> s = new java.util.LinkedHashSet<T>(s1);
 		s.retainAll(s2);
 		return s;
 	}
 
-	public static <T> java.util.HashSet<T> set_difference(final java.util.Set<T> s1, final java.util.Set<T> s2) {
-		final java.util.HashSet<T> s = new java.util.HashSet<T>(s1);
+	public static <T> java.util.Set<T> set_difference(final java.util.Set<T> s1, final java.util.Set<T> s2) {
+		final java.util.Set<T> s = new java.util.LinkedHashSet<T>(s1);
 		s.removeAll(s2);
 		return s;
 	}
 
-	public static <T> java.util.HashSet<T> set_symdiff(final java.util.Set<T> s1, final java.util.Set<T> s2) {
+	public static <T> java.util.Set<T> set_symdiff(final java.util.Set<T> s1, final java.util.Set<T> s2) {
 		return set_union(set_difference(s1, s2), set_difference(s2, s1));
 	}
 }
diff --git a/src/java/boa/functions/BoaNormalFormIntrinsics.java b/src/java/boa/functions/BoaNormalFormIntrinsics.java
index b38e37191..fa00d25f3 100644
--- a/src/java/boa/functions/BoaNormalFormIntrinsics.java
+++ b/src/java/boa/functions/BoaNormalFormIntrinsics.java
@@ -2429,7 +2429,7 @@ public static Expression simplify(final Expression e, final ExpressionKind paren
 			case LOGICAL_AND:
 			case LOGICAL_OR:
 				final List<Expression> exps = new ArrayList<Expression>();
-				final Set<Expression> seen = new HashSet<Expression>();
+				final Set<Expression> seen = new LinkedHashSet<Expression>();
 
 				// recurse in and simplify inner expressions
 				OUTER:
@@ -2928,7 +2928,7 @@ public static String getCryptHash(final PDGSlicer pdgslice, final String algorit
 	 * @throws UnsupportedEncodingException if the character encoding used is not supported by JVM
 	 */
 	private static String getCryptHash(final Stack<PDGNode> nodes, final String algorithm) throws NoSuchAlgorithmException, UnsupportedEncodingException {
-		final Set<PDGNode> visited = new HashSet<PDGNode>();
+		final Set<PDGNode> visited = new LinkedHashSet<PDGNode>();
 		final StringBuilder sb = new StringBuilder();
 
 		while (nodes.size() != 0) {
diff --git a/src/java/boa/functions/BoaSpecialIntrinsics.java b/src/java/boa/functions/BoaSpecialIntrinsics.java
index 76b78ba06..8bac764b1 100644
--- a/src/java/boa/functions/BoaSpecialIntrinsics.java
+++ b/src/java/boa/functions/BoaSpecialIntrinsics.java
@@ -87,29 +87,29 @@ public static void azzert(final boolean condition) {
 	 * @return The array
 	 */
 	@FunctionSpec(name = "new", returnType = "array of int", formalParameters = { "array of int", "int", "int" })
-	public static long[] newInt(long[] a, long size, long val) {
-		long[] arr = new long[(int)size];
+	public static Long[] newInt(Long[] a, long size, long val) {
+		Long[] arr = new Long[(int)size];
 		for (int i = 0; i < size; i++)
 			arr[i] = val;
 		return arr;
 	}
 	@FunctionSpec(name = "new", returnType = "array of float", formalParameters = { "array of float", "int", "float" })
-	public static double[] newDouble(double[] a, long size, double val) {
-		double[] arr = new double[(int)size];
+	public static Double[] newDouble(Double[] a, long size, double val) {
+		Double[] arr = new Double[(int)size];
 		for (int i = 0; i < size; i++)
 			arr[i] = val;
 		return arr;
 	}
 	@FunctionSpec(name = "new", returnType = "array of bool", formalParameters = { "array of bool", "int", "bool" })
-	public static boolean[] newBoolean(boolean[] a, long size, boolean val) {
-		boolean[] arr = new boolean[(int)size];
+	public static Boolean[] newBoolean(Boolean[] a, long size, boolean val) {
+		Boolean[] arr = new Boolean[(int)size];
 		for (int i = 0; i < size; i++)
 			arr[i] = val;
 		return arr;
 	}
 	@FunctionSpec(name = "new", returnType = "array of time", formalParameters = { "array of time", "int", "time" })
-	public static long[] newTime(long[] a, long size, long val) {
-		long[] arr = new long[(int)size];
+	public static Long[] newTime(Long[] a, long size, long val) {
+		Long[] arr = new Long[(int)size];
 		for (int i = 0; i < size; i++)
 			arr[i] = val;
 		return arr;
diff --git a/src/java/boa/graphs/Node.java b/src/java/boa/graphs/Node.java
index cdb6c7023..d4e878bac 100644
--- a/src/java/boa/graphs/Node.java
+++ b/src/java/boa/graphs/Node.java
@@ -17,7 +17,7 @@
 package boa.graphs;
 
 import java.util.ArrayList;
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
 
@@ -40,8 +40,8 @@ public abstract class Node<N extends Node<N, E>, E extends Edge<N, E>> implement
 	protected Statement stmt;
 	protected Expression expr;
 
-	protected final Set<E> inEdges = new HashSet<E>();
-	protected final Set<E> outEdges = new HashSet<E>();
+	protected final Set<E> inEdges = new LinkedHashSet<E>();
+	protected final Set<E> outEdges = new LinkedHashSet<E>();
 
 	@Override
 	public int compareTo(final N node) {
@@ -110,14 +110,14 @@ public List<N> getSuccessorsList() {
 	}
 
 	public List<N> getPredecessors() {
-		final Set<N> nodes = new HashSet<N>();
+		final Set<N> nodes = new LinkedHashSet<N>();
 		for (final E e : this.inEdges)
 			nodes.add(e.getSrc());
 		return new ArrayList<N>(nodes);
 	}
 
 	public List<N> getSuccessors() {
-		final Set<N> nodes = new HashSet<N>();
+		final Set<N> nodes = new LinkedHashSet<N>();
 		for (final E e : this.outEdges)
 			nodes.add(e.getDest());
 		return new ArrayList<N>(nodes);
diff --git a/src/java/boa/graphs/cdg/CDG.java b/src/java/boa/graphs/cdg/CDG.java
index 4664cfa2f..0cdf038d5 100644
--- a/src/java/boa/graphs/cdg/CDG.java
+++ b/src/java/boa/graphs/cdg/CDG.java
@@ -18,8 +18,8 @@
 
 import java.util.ArrayList;
 import java.util.Collections;
-import java.util.HashSet;
 import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -43,7 +43,7 @@ public class CDG {
     private Method md;
     private CDGNode entryNode;
     private CFG cfg;
-    private final Set<CDGNode> nodes = new HashSet<CDGNode>();
+    private final Set<CDGNode> nodes = new LinkedHashSet<CDGNode>();
 
     /**
      * Constructs a control dependence graph
diff --git a/src/java/boa/graphs/cdg/CDGNode.java b/src/java/boa/graphs/cdg/CDGNode.java
index 7cac1fb73..119a75f6f 100644
--- a/src/java/boa/graphs/cdg/CDGNode.java
+++ b/src/java/boa/graphs/cdg/CDGNode.java
@@ -16,7 +16,7 @@
  */
 package boa.graphs.cdg;
 
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.Set;
 
 import boa.graphs.cfg.CFGNode;
@@ -57,7 +57,7 @@ public CDGNode(final TreeNode node) {
     public CDGNode(int id) {
         this.cfgnode = null;
         this.id = id;
-        this.useVariables = new HashSet<String>();
+        this.useVariables = new LinkedHashSet<String>();
     }
 
     public CFGNode getCfgNode() {
@@ -76,7 +76,7 @@ public Set<String> getUseVariables() {
         return useVariables;
     }
 
-    public void setUseVariables(final HashSet<String> useVariables) {
+    public void setUseVariables(final Set<String> useVariables) {
         this.useVariables = useVariables;
     }
 
diff --git a/src/java/boa/graphs/cfg/CFG.java b/src/java/boa/graphs/cfg/CFG.java
index e34dd2384..1c8ece201 100644
--- a/src/java/boa/graphs/cfg/CFG.java
+++ b/src/java/boa/graphs/cfg/CFG.java
@@ -19,8 +19,9 @@
 
 import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.Map;
+import java.util.Set;
 
 import boa.functions.BoaAstIntrinsics;
 import boa.types.Ast.Expression;
@@ -44,14 +45,14 @@ public class CFG {
 	protected Method md;
 	protected String class_name;
 
-	protected final HashSet<CFGNode> nodes = new HashSet<CFGNode>();
+	protected final Set<CFGNode> nodes = new LinkedHashSet<CFGNode>();
 	protected CFGNode entryNode;
 	protected CFGNode exitNode;
 
-	protected final HashSet<CFGNode> outs = new HashSet<CFGNode>();
-	protected final HashSet<CFGNode> ins = new HashSet<CFGNode>();
-	protected final HashSet<CFGNode> breaks = new HashSet<CFGNode>();
-	protected final HashSet<CFGNode> returns = new HashSet<CFGNode>();
+	protected final Set<CFGNode> outs = new LinkedHashSet<CFGNode>();
+	protected final Set<CFGNode> ins = new LinkedHashSet<CFGNode>();
+	protected final Set<CFGNode> breaks = new LinkedHashSet<CFGNode>();
+	protected final Set<CFGNode> returns = new LinkedHashSet<CFGNode>();
 
 	protected boolean isLoopPresent = false;
 	protected boolean isBranchPresent = false;
@@ -91,15 +92,15 @@ public String getClass_name() {
 		return class_name;
 	}
 
-	public HashSet<CFGNode> getNodes() {
+	public Set<CFGNode> getNodes() {
 		return nodes;
 	}
 
-	public HashSet<CFGNode> getOuts() {
+	public Set<CFGNode> getOuts() {
 		return outs;
 	}
 
-	public HashSet<CFGNode> getIns() {
+	public Set<CFGNode> getIns() {
 		return ins;
 	}
 
@@ -208,7 +209,7 @@ protected void mergeSeq(final CFGNode branch) {
 		outs.add(branch);
 	}
 
-	protected void mergeBranches(final CFG target, final HashSet<CFGNode> saveOuts) {
+	protected void mergeBranches(final CFG target, final Set<CFGNode> saveOuts) {
 		if (target.getNodes().size() == 0)
 			return;
 
diff --git a/src/java/boa/graphs/cfg/CFGNode.java b/src/java/boa/graphs/cfg/CFGNode.java
index 50c9cc3ab..484aa25f1 100644
--- a/src/java/boa/graphs/cfg/CFGNode.java
+++ b/src/java/boa/graphs/cfg/CFGNode.java
@@ -18,7 +18,8 @@
 package boa.graphs.cfg;
 
 import java.util.HashMap;
-import java.util.HashSet;
+import java.util.LinkedHashSet;
+import java.util.Set;
 
 import boa.graphs.Node;
 import boa.types.Ast.Expression.ExpressionKind;
@@ -35,12 +36,12 @@ public class CFGNode extends Node<CFGNode, CFGEdge> {
 	private int objectNameId;
 	private int classNameId;
 	private int numOfParameters = 0;
-	private HashSet<Integer> parameters;
+	private Set<Integer> parameters;
 
 	private static final HashMap<String, Integer> idOfLabel = new HashMap<String, Integer>();
 	private static final HashMap<Integer, String> labelOfID = new HashMap<Integer, String>();
 
-	private HashSet<String> useVariables;
+	private Set<String> useVariables;
 	private String defVariables;
 
 	public CFGNode() {
@@ -55,7 +56,7 @@ public CFGNode(final String methodName, final NodeType kind, final String classN
 	}
 
 	public CFGNode(final String methodName, final NodeType kind, final String className,
-			final String objectName, final int numOfParameters, final HashSet<Integer> datas) {
+			final String objectName, final int numOfParameters, final Set<Integer> datas) {
 		super(kind);
 		this.methodId = convertLabel(methodName);
 		if (className == null) {
@@ -64,7 +65,7 @@ public CFGNode(final String methodName, final NodeType kind, final String classN
 			this.classNameId = convertLabel(className);
 		}
 		this.objectNameId = convertLabel(objectName);
-		this.parameters = new HashSet<Integer>(datas);
+		this.parameters = new LinkedHashSet<Integer>(datas);
 		this.numOfParameters = numOfParameters;
 	}
 
@@ -91,11 +92,11 @@ public int getNumOfParameters() {
 		return this.numOfParameters;
 	}
 
-	public void setParameters(final HashSet<Integer> parameters) {
+	public void setParameters(final Set<Integer> parameters) {
 		this.parameters = parameters;
 	}
 
-	public HashSet<Integer> getParameters() {
+	public Set<Integer> getParameters() {
 		return this.parameters;
 	}
 
@@ -115,7 +116,7 @@ public String getClassName() {
 		return labelOfID.get(this.classNameId);
 	}
 
-	public HashSet<String> getUseVariables() {
+	public Set<String> getUseVariables() {
 		if (this.useVariables == null)
 			processUse();
 		return this.useVariables;
@@ -184,7 +185,7 @@ private static String processDef(final boa.types.Ast.Expression expr) {
 	}
 
 	private void processUse() {
-		final HashSet<String> useVar = new HashSet<String>();
+		final Set<String> useVar = new LinkedHashSet<String>();
 		if (this.expr != null) {
 			if (this.expr.getKind() == ExpressionKind.ASSIGN) {
 				processUse(useVar, this.expr.getExpressions(1));
@@ -195,7 +196,7 @@ private void processUse() {
 		this.useVariables = useVar;
 	}
 
-	private static void processUse(final HashSet<String> useVar, final boa.types.Ast.Expression expr) {
+	private static void processUse(final Set<String> useVar, final boa.types.Ast.Expression expr) {
 		if (expr.getKind() == ExpressionKind.ASSIGN) {
 			processUse(useVar, expr.getExpressions(1));
 			return;
@@ -219,7 +220,7 @@ private static void processUse(final HashSet<String> useVar, final boa.types.Ast
 		}
 	}
 
-	private static void processUse(final HashSet<String> useVar, final boa.types.Ast.Variable vardecls) {
+	private static void processUse(final Set<String> useVar, final boa.types.Ast.Variable vardecls) {
 		if (vardecls.hasInitializer()) {
 			processUse(useVar, vardecls.getInitializer());
 		}
diff --git a/src/java/boa/graphs/ddg/DDG.java b/src/java/boa/graphs/ddg/DDG.java
index d189c58ae..8c30e0c8d 100644
--- a/src/java/boa/graphs/ddg/DDG.java
+++ b/src/java/boa/graphs/ddg/DDG.java
@@ -32,7 +32,7 @@ public class DDG {
     private Method md;
     private DDGNode entryNode;
     private CFG cfg;
-    private final HashSet<DDGNode> nodes = new HashSet<DDGNode>();
+    private final Set<DDGNode> nodes = new LinkedHashSet<DDGNode>();
     private final HashMap<DDGNode, Set<DDGNode>> defUseChain = new HashMap<DDGNode, Set<DDGNode>>();
     //private HashMap<DDGNode, Set<DDGNode>> useDefChain; //TODO: needs reaching-def analysis
 
@@ -99,7 +99,7 @@ public CFG getCfg() {
      *
      * @return the set of all the nodes in the graph
      */
-    public HashSet<DDGNode> getNodes() { return nodes; }
+    public Set<DDGNode> getNodes() { return nodes; }
 
     public DDGNode[] sortNodes() {
         try {
@@ -130,7 +130,7 @@ public HashMap<DDGNode, Set<DDGNode>> getDefUseChain() {
      * @return definition nodes
      */
     public Set<DDGNode> getDefNodes(final String var) {
-        final Set<DDGNode> defNodes = new HashSet<DDGNode>();
+        final Set<DDGNode> defNodes = new LinkedHashSet<DDGNode>();
         for (final DDGNode n : defUseChain.keySet()) {
             if (n.getDefVariable() != null && n.getDefVariable().equals(var))
                 defNodes.add(n);
@@ -260,7 +260,7 @@ private void formDefUseChains(final Map<Integer, InOut> liveVar, CFG cfg) {
                         if (n.getDefVariables().equals(p.var)) {
                             final DDGNode useNode = getNode(p.node);
                             if (!defUseChain.containsKey(defNode))
-                                defUseChain.put(defNode, new HashSet<DDGNode>());
+                                defUseChain.put(defNode, new LinkedHashSet<DDGNode>());
                             defUseChain.get(defNode).add(useNode);
                             // connect nodes for constructing the graph
                             new DDGEdge(defNode, useNode, p.var);
diff --git a/src/java/boa/graphs/ddg/DDGNode.java b/src/java/boa/graphs/ddg/DDGNode.java
index 97f7f5cb8..9d5d9225b 100644
--- a/src/java/boa/graphs/ddg/DDGNode.java
+++ b/src/java/boa/graphs/ddg/DDGNode.java
@@ -16,7 +16,7 @@
  */
 package boa.graphs.ddg;
 
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.Set;
 
 import boa.graphs.Node;
@@ -30,7 +30,7 @@
  */
 public class DDGNode extends Node<DDGNode, DDGEdge> {
     protected String defVariable;
-    protected HashSet<String> useVariables = new HashSet<String>();
+    protected Set<String> useVariables = new LinkedHashSet<String>();
 
     /**
      * Constructs a DDG node.
@@ -59,7 +59,7 @@ public void setDefVariable(final String defVariables) {
         this.defVariable = defVariables;
     }
 
-    public void setUseVariables(final HashSet<String> useVariables) {
+    public void setUseVariables(final Set<String> useVariables) {
         this.useVariables = useVariables;
     }
 
diff --git a/src/java/boa/graphs/pdg/PDG.java b/src/java/boa/graphs/pdg/PDG.java
index aeeb17557..1a76a7d7f 100644
--- a/src/java/boa/graphs/pdg/PDG.java
+++ b/src/java/boa/graphs/pdg/PDG.java
@@ -41,7 +41,7 @@
 public class PDG {
     private Method md;
     private PDGNode entryNode;
-    private final HashSet<PDGNode> nodes = new HashSet<PDGNode>();
+    private final Set<PDGNode> nodes = new LinkedHashSet<PDGNode>();
     private boolean normalize = false;
     private int hashcode;
 
@@ -117,7 +117,7 @@ public PDGNode getEntryNode() {
      *
      * @return the set of all the nodes in the graph
      */
-    public HashSet<PDGNode> getNodes() {
+    public Set<PDGNode> getNodes() {
         return nodes;
     }
 
@@ -192,7 +192,7 @@ public void normalize() throws Exception {
                 return;
             final Stack<PDGNode> nodes = new Stack<PDGNode>();
             nodes.add(entryNode);
-            final Set<PDGNode> visited = new HashSet<PDGNode>();
+            final Set<PDGNode> visited = new LinkedHashSet<PDGNode>();
             final Map<String, String> normalizedVars = new HashMap<String, String>();
             int varCount = 1;
             // if normalization is enabled then normalize node expression
@@ -212,7 +212,7 @@ public void normalize() throws Exception {
                             node.setDefVariable(normalizedVars.get(node.getDefVariable()));
                         }
                         // use variables
-                        final HashSet<String> useVars = new HashSet<String>();
+                        final Set<String> useVars = new LinkedHashSet<String>();
                         for (final String dVar : node.getUseVariables()) {
                             if (dVar != null) {
                                 if (!normalizedVars.containsKey(dVar)) {
@@ -297,8 +297,8 @@ public boolean equals(final Object o) {
 
         final Stack<PDGNode> nodes1 = new Stack<PDGNode>();
         final Stack<PDGNode> nodes2 = new Stack<PDGNode>();
-        final Set<PDGNode> visited1 = new HashSet<PDGNode>();
-        final Set<PDGNode> visited2 = new HashSet<PDGNode>();
+        final Set<PDGNode> visited1 = new LinkedHashSet<PDGNode>();
+        final Set<PDGNode> visited2 = new LinkedHashSet<PDGNode>();
         nodes1.add(entryNode);
         nodes2.add(pdg.getEntryNode());
 
@@ -366,7 +366,7 @@ public int hashCode() {
         if (hashcode == 0 && entryNode != null) {
             final Stack<PDGNode> nodes = new Stack<PDGNode>();
             nodes.add(entryNode);
-            final Set<PDGNode> visited = new HashSet<PDGNode>();
+            final Set<PDGNode> visited = new LinkedHashSet<PDGNode>();
             final StringBuilder sb = new StringBuilder();
             while (nodes.size() != 0) {
                 final PDGNode node = nodes.pop();
diff --git a/src/java/boa/graphs/pdg/PDGNode.java b/src/java/boa/graphs/pdg/PDGNode.java
index 34bad2c9e..192e0c1cf 100644
--- a/src/java/boa/graphs/pdg/PDGNode.java
+++ b/src/java/boa/graphs/pdg/PDGNode.java
@@ -17,7 +17,7 @@
 package boa.graphs.pdg;
 
 import java.util.ArrayList;
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
 
@@ -32,7 +32,7 @@
  */
 public class PDGNode extends Node<PDGNode, PDGEdge> {
     private String defVariable;
-    private Set<String> useVariables = new HashSet<String>();
+    private Set<String> useVariables = new LinkedHashSet<String>();
 
     /**
      * Constructs a PDG node.
@@ -52,7 +52,7 @@ public void setDefVariable(final String defVariables) {
         this.defVariable = defVariables;
     }
 
-    public void setUseVariables(final HashSet<String> useVariables) {
+    public void setUseVariables(final Set<String> useVariables) {
         this.useVariables = useVariables;
     }
 
diff --git a/src/java/boa/graphs/slicers/CFGSlicer.java b/src/java/boa/graphs/slicers/CFGSlicer.java
index d6d4d792f..0bec9c183 100644
--- a/src/java/boa/graphs/slicers/CFGSlicer.java
+++ b/src/java/boa/graphs/slicers/CFGSlicer.java
@@ -20,7 +20,7 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -107,14 +107,14 @@ public ArrayList<CFGNode> getSlice() {
     private void getSlice(final CFG cfg, final List<CFGNode> slicingNodes) throws Exception {
         if (slicingNodes.size() == 0) return;
 
-        final Set<CFGNode> inSlice = new HashSet<CFGNode>(slicingNodes);
-        final Set<CFGNode> controlInflNodes = new HashSet<CFGNode>();
+        final Set<CFGNode> inSlice = new LinkedHashSet<CFGNode>(slicingNodes);
+        final Set<CFGNode> controlInflNodes = new LinkedHashSet<CFGNode>();
         final Map<Integer, Set<CFGNode>> infl = getInfluence(new PDTree(cfg), cfg);
 
         final BoaAbstractTraversal<Set<String>> slicer = new BoaAbstractTraversal<Set<String>>(true, true) {
             protected Set<String> preTraverse(final CFGNode node) throws Exception {
                 // in(n) = \/(pred) out(pred)
-                final Set<String> in = new HashSet<String>();
+                final Set<String> in = new LinkedHashSet<String>();
                 for (final CFGNode p : node.getPredecessors()) {
                     final Set<String> pred = getValue(p);
                     if (pred != null)
@@ -123,7 +123,7 @@ protected Set<String> preTraverse(final CFGNode node) throws Exception {
 
                 // gen(n) = def(n) and (ref(n) /\ in(n) != {} or inSlice(n))
                 String gen = null;
-                final Set<String> refIn = new HashSet<String>(node.getUseVariables());
+                final Set<String> refIn = new LinkedHashSet<String>(node.getUseVariables());
                 refIn.retainAll(in);
                 if (refIn.size() != 0 || inSlice.contains(node))
                     if (node.getDefVariables() != null)
@@ -133,14 +133,14 @@ protected Set<String> preTraverse(final CFGNode node) throws Exception {
                 // use def directly
 
                 // out(n) = gen(n) \/ (in(n) - kill(n))
-                final Set<String> out = new HashSet<String>(in);
+                final Set<String> out = new LinkedHashSet<String>(in);
                 if (node.getDefVariables() != null)
                     out.remove(node.getDefVariables());
                 if (gen != null)
                     out.add(gen);
 
                 // inSlice(n) if ref(n) /\ out(n) != {}
-                final Set<String> refOut = new HashSet<String>(node.getUseVariables());
+                final Set<String> refOut = new LinkedHashSet<String>(node.getUseVariables());
                 refOut.retainAll(out);
                 if (refOut.size() != 0)
                     inSlice.add(node);
@@ -156,7 +156,7 @@ protected Set<String> preTraverse(final CFGNode node) throws Exception {
             public void traverse(final CFGNode node, boolean flag) throws Exception {
                 if (flag) {
                     currentResult = preTraverse(node);
-                    outputMapObj.put(node.getId(), new HashSet<String>(currentResult));
+                    outputMapObj.put(node.getId(), new LinkedHashSet<String>(currentResult));
                 } else {
                     outputMapObj.put(node.getId(), preTraverse(node));
                 }
@@ -167,7 +167,7 @@ public void traverse(final CFGNode node, boolean flag) throws Exception {
             @Override
             @SuppressWarnings({"unchecked"})
             public boolean invoke(final Object current, final Object previous) throws Exception {
-                return boa.functions.BoaIntrinsics.set_symdiff((HashSet<String>) current, (HashSet<String>) previous).size() == 0;
+                return boa.functions.BoaIntrinsics.set_symdiff((LinkedHashSet<String>) current, (LinkedHashSet<String>) previous).size() == 0;
             }
         };
 
@@ -205,7 +205,7 @@ private Map<Integer, Set<CFGNode>> getInfluence(final PDTree pdTree, final CFG c
             final TreeNode srcParent = pdTree.getNode(enodes[0]).getParent();
             TreeNode destination = pdTree.getNode(enodes[1]);
             if (!contolDependentMap.containsKey(enodes[0]))
-                contolDependentMap.put(enodes[0], new HashSet<CFGNode>());
+                contolDependentMap.put(enodes[0], new LinkedHashSet<CFGNode>());
             while (!srcParent.equals(destination)) {
                 contolDependentMap.get(enodes[0]).add(cfg.getNode(destination.getNodeId()));
                 destination = destination.getParent();
diff --git a/src/java/boa/graphs/slicers/PDGSlicer.java b/src/java/boa/graphs/slicers/PDGSlicer.java
index 4e0cb89d5..47ce8f40f 100644
--- a/src/java/boa/graphs/slicers/PDGSlicer.java
+++ b/src/java/boa/graphs/slicers/PDGSlicer.java
@@ -24,7 +24,7 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -45,7 +45,7 @@
 public class PDGSlicer {
     private final Method md;
     private final ArrayList<PDGNode> entryNodes = new ArrayList<PDGNode>();
-    private final HashSet<PDGNode> slice = new HashSet<PDGNode>();
+    private final Set<PDGNode> slice = new LinkedHashSet<PDGNode>();
     private boolean normalize = false;
     private int hashcode = 0;
 
@@ -178,7 +178,7 @@ public ArrayList<PDGNode> getEntrynodesList() {
      *
      * @return all the nodes in the slice
      */
-    public HashSet<PDGNode> getSlice() {
+    public Set<PDGNode> getSlice() {
         return slice;
     }
 
@@ -256,7 +256,7 @@ private void traverse() throws Exception {
                             node.setDefVariable(normalizedVars.get(node.getDefVariable()));
                         }
                         // use variables
-                        final HashSet<String> useVars = new HashSet<String>();
+                        final Set<String> useVars = new LinkedHashSet<String>();
                         for (final String dVar : node.getUseVariables()) {
                             if (dVar != null) {
                                 if (!normalizedVars.containsKey(dVar)) {
@@ -308,8 +308,8 @@ public boolean equals(final Object o) {
 
         final Stack<PDGNode> nodes1 = new Stack<PDGNode>();
         final Stack<PDGNode> nodes2 = new Stack<PDGNode>();
-        final Set<PDGNode> visited1 = new HashSet<PDGNode>();
-        final Set<PDGNode> visited2 = new HashSet<PDGNode>();
+        final Set<PDGNode> visited1 = new LinkedHashSet<PDGNode>();
+        final Set<PDGNode> visited2 = new LinkedHashSet<PDGNode>();
         nodes1.addAll(entryNodes);
         nodes2.addAll(pdgSlicer.getEntrynodesList());
 
diff --git a/src/java/boa/graphs/trees/DTree.java b/src/java/boa/graphs/trees/DTree.java
index 0eacc7440..b926f8172 100644
--- a/src/java/boa/graphs/trees/DTree.java
+++ b/src/java/boa/graphs/trees/DTree.java
@@ -32,7 +32,7 @@
 public class DTree {
     private Method md;
     private TreeNode rootNode;
-    private final HashSet<TreeNode> nodes = new HashSet<TreeNode>();
+    private final Set<TreeNode> nodes = new LinkedHashSet<TreeNode>();
     private boolean isEntryNode = false; // as specified in ferrante-1987 paper on PDG
 
     /**
@@ -106,7 +106,7 @@ public TreeNode getRootNode() {
      *
      * @return the set of all the nodes in the tree
      */
-    public HashSet<TreeNode> getNodes() {
+    public Set<TreeNode> getNodes() {
         return nodes;
     }
 
@@ -163,14 +163,14 @@ private Map<CFGNode, Set<CFGNode>> computeDominators(final CFG cfg) {
         if (cfg.getNodes().size() > 2) {
             for (final CFGNode n : cfg.getNodes()) {
                 if (n.getNodeId() == 0)
-                    pDomMap.put(n, new HashSet<CFGNode>(Collections.singletonList(n)));
+                    pDomMap.put(n, new LinkedHashSet<CFGNode>(Collections.singletonList(n)));
                 else
                     pDomMap.put(n, cfg.getNodes());
             }
         } else {
             final CFGNode startNode = cfg.getNode(0);
-            pDomMap.put(startNode, new HashSet<CFGNode>(Collections.singletonList(startNode)));
-            pDomMap.put(cfg.getNode(1), new HashSet<CFGNode>(cfg.getNodes()));
+            pDomMap.put(startNode, new LinkedHashSet<CFGNode>(Collections.singletonList(startNode)));
+            pDomMap.put(cfg.getNode(1), new LinkedHashSet<CFGNode>(cfg.getNodes()));
         }
 
         final Map<CFGNode, Set<CFGNode>> currentPDomMap = new HashMap<CFGNode, Set<CFGNode>>();
@@ -178,7 +178,7 @@ private Map<CFGNode, Set<CFGNode>> computeDominators(final CFG cfg) {
         while (!saturated) { // fix point iteration
             int changeCount = 0;
             for (final CFGNode n : cfg.getNodes()) {
-                final Set<CFGNode> currentPDom = new HashSet<CFGNode>();
+                final Set<CFGNode> currentPDom = new LinkedHashSet<CFGNode>();
 
                 // Intersection[pred(node)]
                 boolean first = true;
@@ -193,7 +193,7 @@ private Map<CFGNode, Set<CFGNode>> computeDominators(final CFG cfg) {
                 // D[n] = {n} Union (Intersection[pred[node]])
                 currentPDom.add(n);
 
-                final Set<CFGNode> diff = new HashSet<CFGNode>(pDomMap.get(n));
+                final Set<CFGNode> diff = new LinkedHashSet<CFGNode>(pDomMap.get(n));
                 diff.removeAll(currentPDom);
                 if (diff.size() > 0)
                     changeCount++;
diff --git a/src/java/boa/graphs/trees/PDTree.java b/src/java/boa/graphs/trees/PDTree.java
index 341a7d5b2..73799fb22 100644
--- a/src/java/boa/graphs/trees/PDTree.java
+++ b/src/java/boa/graphs/trees/PDTree.java
@@ -32,7 +32,7 @@
 public class PDTree {
     private Method md;
     private TreeNode rootNode;
-    private final HashSet<TreeNode> nodes = new HashSet<TreeNode>();
+    private final Set<TreeNode> nodes = new LinkedHashSet<TreeNode>();
     private boolean hasEntryNode = false; // as specified in ferrante-1987 paper on PDG
 
     /**
@@ -108,7 +108,7 @@ public TreeNode getRootNode() {
      *
      * @return the set of all the nodes in the tree
      */
-    public HashSet<TreeNode> getNodes() {
+    public Set<TreeNode> getNodes() {
         return nodes;
     }
 
diff --git a/src/java/boa/graphs/trees/TreeNode.java b/src/java/boa/graphs/trees/TreeNode.java
index beb61132e..357b2b941 100644
--- a/src/java/boa/graphs/trees/TreeNode.java
+++ b/src/java/boa/graphs/trees/TreeNode.java
@@ -17,7 +17,7 @@
 package boa.graphs.trees;
 
 import java.util.ArrayList;
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
 
@@ -33,7 +33,7 @@ public class TreeNode extends Node<TreeNode, TreeEdge> {
     private TreeNode parent;
 
     private String defVariable;
-    private HashSet<String> useVariables;
+    private Set<String> useVariables;
 
     private final ArrayList<TreeNode> children = new ArrayList<TreeNode>();
     private final CFGNode cfgnode;
@@ -61,7 +61,7 @@ public TreeNode(final CFGNode node) {
     public TreeNode(final int id) {
         this.cfgnode = null;
         this.id = id;
-        this.useVariables = new HashSet<String>();
+        this.useVariables = new LinkedHashSet<String>();
     }
 
     public TreeNode getParent() {
@@ -88,7 +88,7 @@ public void setDefVariable(final String defVariables) {
         this.defVariable = defVariables;
     }
 
-    public void setUseVariables(final HashSet<String> useVariables) {
+    public void setUseVariables(final Set<String> useVariables) {
         this.useVariables = useVariables;
     }
 
diff --git a/src/java/boa/runtime/BoaAbstractTraversal.java b/src/java/boa/runtime/BoaAbstractTraversal.java
index 5298f8bef..b45030258 100644
--- a/src/java/boa/runtime/BoaAbstractTraversal.java
+++ b/src/java/boa/runtime/BoaAbstractTraversal.java
@@ -412,7 +412,7 @@ public final void traverse(final boa.graphs.cfg.CFG cfg, final Traversal.Travers
 						prevOutputMapObj = new java.util.HashMap<Long, T1>(outputMapObj);
 						traverse(cfg, direction, kind);
 						fixpFlag = true;
-						final java.util.HashSet<CFGNode> nl = cfg.getNodes();
+						final java.util.Set<CFGNode> nl = cfg.getNodes();
 						for (final CFGNode node : nl) {
 							boolean curFlag = outputMapObj.containsKey(node.getId());
 							if (curFlag) {
@@ -433,7 +433,7 @@ public final void traverse(final boa.graphs.cfg.CFG cfg, final Traversal.Travers
 					break;
 				case HYBRID:
 					prevOutputMapObj = new java.util.HashMap<Long, T1>();
-					final java.util.Set<Long> visitedNodes = new java.util.HashSet<Long>();
+					final java.util.Set<Long> visitedNodes = new java.util.LinkedHashSet<Long>();
 					final CFGNode[] nl = cfg.sortNodes();
 					if (nl.length != 0) {
 						if (this.isFlowSensitive) {
@@ -521,7 +521,7 @@ public final void traverseWithFixp(final CFG cfg, final Traversal.TraversalDirec
 				outputMapObj = new java.util.HashMap<Long, T1>();
 			}
 			if (cfg.getNodes().size() != 0) {
-				final java.util.Set<Long> visitedNodes = new java.util.HashSet<Long>();
+				final java.util.Set<Long> visitedNodes = new java.util.LinkedHashSet<Long>();
 				switch (kind) {
 					case WORKLIST_POSTORDER:
 						Queue<CFGNode> queue = new LinkedList<CFGNode>();
@@ -565,7 +565,7 @@ public final void traverse(final boa.graphs.cfg.CFG cfg, final Traversal.Travers
 					outputMapObj = new java.util.HashMap<Long, T1>();
 				}
 				if (cfg.getNodes().size() != 0) {
-					final java.util.Set<Long> visitedNodes = new java.util.HashSet<Long>();
+					final java.util.Set<Long> visitedNodes = new java.util.LinkedHashSet<Long>();
 					final CFGNode[] nl = cfg.sortNodes();
 					switch (kind) {
 						case DFS:
@@ -661,7 +661,7 @@ public final void traverse(final boa.graphs.cdg.CDG cdg, final Traversal.Travers
 					outputMapObj = new java.util.HashMap<Long, T1>();
 				}
 				if (cdg.getNodes().size() != 0) {
-					final java.util.Set<Long> visitedNodes = new java.util.HashSet<Long>();
+					final java.util.Set<Long> visitedNodes = new java.util.LinkedHashSet<Long>();
 					//final CDGNode[] nl = cdg.sortNodes();
 					switch (kind) {
 						case DFS:
@@ -759,7 +759,7 @@ public final void traverse(final boa.graphs.ddg.DDG ddg, final Traversal.Travers
 					outputMapObj = new java.util.HashMap<Long, T1>();
 				}
 				if (ddg.getNodes().size() != 0) {
-					final java.util.Set<Long> visitedNodes = new java.util.HashSet<Long>();
+					final java.util.Set<Long> visitedNodes = new java.util.LinkedHashSet<Long>();
 					//final CDGNode[] nl = cdg.sortNodes();
 					switch (kind) {
 						case DFS:
@@ -857,7 +857,7 @@ public final void traverse(final boa.graphs.pdg.PDG pdg, final Traversal.Travers
 					outputMapObj = new java.util.HashMap<Long, T1>();
 				}
 				if (pdg.getNodes().size() != 0) {
-					final java.util.Set<Long> visitedNodes = new java.util.HashSet<Long>();
+					final java.util.Set<Long> visitedNodes = new java.util.LinkedHashSet<Long>();
 					//final CDGNode[] nl = cdg.sortNodes();
 					switch (kind) {
 						case DFS:
@@ -955,7 +955,7 @@ public final void traverse(final boa.graphs.slicers.PDGSlicer pdgslicer, final T
 					outputMapObj = new java.util.HashMap<Long, T1>();
 				}
 				if (pdgslicer.getSlice().size() != 0) {
-					final java.util.Set<Long> visitedNodes = new java.util.HashSet<Long>();
+					final java.util.Set<Long> visitedNodes = new java.util.LinkedHashSet<Long>();
 					//final CDGNode[] nl = cdg.sortNodes();
 					switch (kind) {
 						case DFS:
@@ -1050,7 +1050,7 @@ public final void traverse(final boa.graphs.trees.PDTree tree, final Traversal.T
 					outputMapObj = new java.util.HashMap<Long, T1>();
 				}
 				if (tree.getNodes().size() != 0) {
-					final java.util.Set<Long> visitedNodes = new java.util.HashSet<Long>();
+					final java.util.Set<Long> visitedNodes = new java.util.LinkedHashSet<Long>();
 					//final CDGNode[] nl = cdg.sortNodes();
 					switch (kind) {
 						case DFS:
diff --git a/src/java/boa/types/BoaArray.java b/src/java/boa/types/BoaArray.java
index b4cc56749..b54b3d64b 100644
--- a/src/java/boa/types/BoaArray.java
+++ b/src/java/boa/types/BoaArray.java
@@ -189,6 +189,18 @@ public String toJavaType() {
 		return this.type.toJavaType() + "[]";
 	}
 
+	/** {@inheritDoc} */
+	@Override
+	public String toBoxedJavaType() {
+		return this.type.toBoxedJavaType() + "[]";
+	}
+
+	/** {@inheritDoc} */
+	@Override
+	public String toInterfaceJavaType() {
+		return this.type.toInterfaceJavaType() + "[]";
+	}
+
 	/** {@inheritDoc} */
 	@Override
 	public String toString() {
diff --git a/src/java/boa/types/BoaMap.java b/src/java/boa/types/BoaMap.java
index a4e7db21f..79fb2c162 100644
--- a/src/java/boa/types/BoaMap.java
+++ b/src/java/boa/types/BoaMap.java
@@ -165,7 +165,13 @@ public String toString() {
 	/** {@inheritDoc} */
 	@Override
 	public String toJavaType() {
-		return "java.util.HashMap<" + this.indexType.toBoxedJavaType() + ", " + this.valueType.toBoxedJavaType() + ">";
+		return "java.util.HashMap<" + this.indexType.toInterfaceJavaType() + ", " + this.valueType.toInterfaceJavaType() + ">";
+	}
+
+	/** {@inheritDoc} */
+	@Override
+	public String toInterfaceJavaType() {
+		return "java.util.Map<" + this.indexType.toInterfaceJavaType() + ", " + this.valueType.toInterfaceJavaType() + ">";
 	}
 
 	/** {@inheritDoc} */
diff --git a/src/java/boa/types/BoaProtoList.java b/src/java/boa/types/BoaProtoList.java
index 169acc1a0..11e874ce4 100644
--- a/src/java/boa/types/BoaProtoList.java
+++ b/src/java/boa/types/BoaProtoList.java
@@ -16,7 +16,7 @@
  */
 package boa.types;
 
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.Set;
 
 import boa.compiler.ast.types.AbstractType;
@@ -195,6 +195,6 @@ public Set<Class<? extends BoaProtoTuple>> reachableTypes() {
 			set.add((Class<? extends BoaProtoTuple>) this.type.getClass());
 			return set;
 		}
-		return new HashSet<Class<? extends BoaProtoTuple>>();
+		return new LinkedHashSet<Class<? extends BoaProtoTuple>>();
 	}
 }
diff --git a/src/java/boa/types/BoaProtoMap.java b/src/java/boa/types/BoaProtoMap.java
index fdfc38691..96824bec9 100644
--- a/src/java/boa/types/BoaProtoMap.java
+++ b/src/java/boa/types/BoaProtoMap.java
@@ -75,6 +75,12 @@ public String toJavaType() {
 		return getEnumClass().getName().replace('$', '.');
 	}
 
+	/** {@inheritDoc} */
+	@Override
+	public String toInterfaceJavaType() {
+		return toJavaType();
+	}
+
 	/** {@inheritDoc} */
 	@Override
 	public String toString() {
diff --git a/src/java/boa/types/BoaProtoTuple.java b/src/java/boa/types/BoaProtoTuple.java
index ae0c4a61e..d779324fb 100644
--- a/src/java/boa/types/BoaProtoTuple.java
+++ b/src/java/boa/types/BoaProtoTuple.java
@@ -16,7 +16,7 @@
  */
 package boa.types;
 
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -98,7 +98,7 @@ public Set<Class<? extends BoaProtoTuple>> reachableTypes() {
 		if (reachableTypesCache != null)
 			return reachableTypesCache;
 
-		reachableTypesCache = new HashSet<Class<? extends BoaProtoTuple>>();
+		reachableTypesCache = new LinkedHashSet<Class<? extends BoaProtoTuple>>();
 		reachableTypesCache.add((Class<? extends BoaProtoTuple>) this.getClass());
 		for (final BoaType t : members)
 			if (t instanceof BoaProtoTuple) {
diff --git a/src/java/boa/types/BoaQueue.java b/src/java/boa/types/BoaQueue.java
index 3b3834cd6..de9fc2d9d 100644
--- a/src/java/boa/types/BoaQueue.java
+++ b/src/java/boa/types/BoaQueue.java
@@ -139,7 +139,7 @@ public String toString() {
 	/** {@inheritDoc} */
 	@Override
 	public String toJavaType() {
-		return "java.util.LinkedList<" + this.type.toBoxedJavaType() + ">";
+		return "java.util.LinkedList<" + this.type.toInterfaceJavaType() + ">";
 	}
 
 	/** {@inheritDoc} */
diff --git a/src/java/boa/types/BoaSet.java b/src/java/boa/types/BoaSet.java
index 5694a9a15..b5d63d0fd 100644
--- a/src/java/boa/types/BoaSet.java
+++ b/src/java/boa/types/BoaSet.java
@@ -140,7 +140,13 @@ public String toString() {
 	/** {@inheritDoc} */
 	@Override
 	public String toJavaType() {
-		return "java.util.HashSet<" + this.type.toBoxedJavaType() + ">";
+		return "java.util.LinkedHashSet<" + this.type.toInterfaceJavaType() + ">";
+	}
+
+	/** {@inheritDoc} */
+	@Override
+	public String toInterfaceJavaType() {
+		return "java.util.Set<" + this.type.toInterfaceJavaType() + ">";
 	}
 
 	/** {@inheritDoc} */
diff --git a/src/java/boa/types/BoaStack.java b/src/java/boa/types/BoaStack.java
index f93490e0f..c76392a62 100644
--- a/src/java/boa/types/BoaStack.java
+++ b/src/java/boa/types/BoaStack.java
@@ -139,7 +139,7 @@ public String toString() {
 	/** {@inheritDoc} */
 	@Override
 	public String toJavaType() {
-		return "java.util.Stack<" + this.type.toBoxedJavaType() + ">";
+		return "java.util.Stack<" + this.type.toInterfaceJavaType() + ">";
 	}
 
 	/** {@inheritDoc} */
diff --git a/src/java/boa/types/BoaType.java b/src/java/boa/types/BoaType.java
index 6dee6bef9..0103830a7 100644
--- a/src/java/boa/types/BoaType.java
+++ b/src/java/boa/types/BoaType.java
@@ -118,6 +118,17 @@ public String toBoxedJavaType() {
 		return toJavaType();
 	}
 
+	/**
+	 * Returns a string representation of the interface Java equivalent of this Boa
+	 * type.
+	 *
+	 * @return A String containing the name of the interface Java type equivalent to this
+	 *         Boa type
+	 */
+	public String toInterfaceJavaType() {
+		return toBoxedJavaType();
+	}
+
 	/**
 	 * Takes a type name and returns one suitable for use as an identifier.
 	 *
diff --git a/templates/BoaJava.stg b/templates/BoaJava.stg
index 4f44a5d04..b3c1316a3 100644
--- a/templates/BoaJava.stg
+++ b/templates/BoaJava.stg
@@ -18,10 +18,6 @@ identifierMap ::= [
 		
 VarDecl(isstatic, type, id) ::= "<if(isstatic)>static <endif><type> ___<id>;<\n>"
 ArrayType(type) ::= "<type>[]"
-MapType(key, value) ::= "java.util.HashMap\<<key>, <value>>"
-StackType(value) ::= "java.util.Stack\<<value>>"
-QueueType(value) ::= "java.util.LinkedList\<<value>>"
-SetType(value) ::= "java.util.HashSet\<<value>>"
 Block(statements) ::= <<
 {
 	<statements:{s | <s>}>}
@@ -125,16 +121,16 @@ new <type>()
 }
 >>
 
-TupleType(name, fields, types, aliases) ::= <<
+TupleType(name, fields, types, types2, aliases) ::= <<
 private class <name>
 {
 	<fields,types:{field,type|<type> ___<field>;}; separator="\n">
 
 	<name>(<fields,types:{field,type|<type> ___<field>}; separator=", ">) {
-		<fields,types,aliases:{field,type,alias|<if(alias)>this.___<field> = ___<field>;<else>this.___<field> = new <type>(___<field>);<endif>}; separator="\n">
+		<fields,types2,aliases:{field,type,alias|<if(alias)>this.___<field> = ___<field>;<else>this.___<field> = new <type>(___<field>);<endif>}; separator="\n">
 	}
 	<name>(<name> tmp) {
-		<fields,types,aliases:{field,type,alias|<if(alias)> this.___<field> = tmp.___<field>;<else> this.___<field> = new <type>(tmp.___<field>);<endif>}; separator="\n">
+		<fields,types2,aliases:{field,type,alias|<if(alias)> this.___<field> = tmp.___<field>;<else> this.___<field> = new <type>(tmp.___<field>);<endif>}; separator="\n">
 	}
 
 	public <name> clone() {
diff --git a/test/datagen/expected/test/known-good/dupe-types.boa.txt b/test/datagen/expected/test/known-good/dupe-types.boa.txt
index 43a439cb1..a01f22b1f 100644
--- a/test/datagen/expected/test/known-good/dupe-types.boa.txt
+++ b/test/datagen/expected/test/known-good/dupe-types.boa.txt
@@ -4,108 +4,108 @@ types[140492550][Account] = src/JLS8/RADemo/Account.java
 types[140492550][Accountant] = src/JLS2/GenDemo/v2/GenDemo.java
 types[140492550][Accountant] = src/JLS3/GenDemo/v2/GenDemo.java
 types[140492550][Accountant] = src/JLS3/GenDemo/v2/GenDemo2.java
+types[140492550][AnnDemo] = src/JLS3/AnnDemo/v1/AnnDemo.java
+types[140492550][AnnDemo] = src/JLS3/AnnDemo/v2/AnnDemo.java
+types[140492550][AnnDemo] = src/JLS3/AnnDemo/v3/AnnDemo.java
 types[140492550][AnnDemo] = src/JLS3/AnnDemo/v4/AnnDemo.java
 types[140492550][AnnDemo] = src/JLS3/AnnDemo/v5/AnnDemo.java
 types[140492550][AnnDemo] = src/JLS3/AnnProcDemo/AnnDemo.java
-types[140492550][AnnDemo] = src/JLS3/AnnDemo/v3/AnnDemo.java
-types[140492550][AnnDemo] = src/JLS3/AnnDemo/v1/AnnDemo.java
-types[140492550][AnnDemo] = src/JLS3/AnnDemo/v2/AnnDemo.java
 types[140492550][AnnProcDemo] = src/JLS3/AnnProcDemo/AnnProcDemo.java
 types[140492550][AssertDemo] = src/JLS2/AssertDemo/v1/AssertDemo.java
-types[140492550][AssertDemo] = src/JLS2/AssertDemo/v4/AssertDemo.java
 types[140492550][AssertDemo] = src/JLS2/AssertDemo/v2/AssertDemo.java
 types[140492550][AssertDemo] = src/JLS2/AssertDemo/v3/AssertDemo.java
+types[140492550][AssertDemo] = src/JLS2/AssertDemo/v4/AssertDemo.java
 types[140492550][BinLitDemo] = src/JLS4/BinLitDemo/BinLitDemo.java
+types[140492550][BoxDemo] = src/JLS3/BoxDemo/v1/BoxDemo.java
 types[140492550][BoxDemo] = src/JLS3/BoxDemo/v2/BoxDemo.java
 types[140492550][BoxDemo] = src/JLS4/BoxDemo/BoxDemo.java
-types[140492550][BoxDemo] = src/JLS3/BoxDemo/v1/BoxDemo.java
 types[140492550][Box] = src/JLS4/BoxDemo/Box.java
 types[140492550][BreakageDemo] = src/JLS4/BreakageDemo/BreakageDemo.java
-types[140492550][Car] = src/JLS8/DMDemo/v3/DMDemo.java
-types[140492550][Car] = src/JLS8/DMDemo/v2/DMDemo.java
 types[140492550][Car] = src/JLS8/DMDemo/v1/DMDemo.java
-types[140492550][CardboardFactory] = src/JLS3/CovarDemo/v2/CovarDemo.java
+types[140492550][Car] = src/JLS8/DMDemo/v2/DMDemo.java
+types[140492550][Car] = src/JLS8/DMDemo/v3/DMDemo.java
 types[140492550][CardboardFactory] = src/JLS3/CovarDemo/v1/CovarDemo.java
-types[140492550][Cardboard] = src/JLS3/CovarDemo/v2/CovarDemo.java
+types[140492550][CardboardFactory] = src/JLS3/CovarDemo/v2/CovarDemo.java
 types[140492550][Cardboard] = src/JLS3/CovarDemo/v1/CovarDemo.java
+types[140492550][Cardboard] = src/JLS3/CovarDemo/v2/CovarDemo.java
 types[140492550][Container] = src/JLS2/GenDemo/v1/GenDemo.java
 types[140492550][Container] = src/JLS3/GenDemo/v1/GenDemo.java
 types[140492550][Container] = src/JLS3/GenDemo/v1/GenDemo1.java
-types[140492550][CopyToDatabaseOrFile] = src/JLS4/CopyToDatabaseOrFile/v2/CopyToDatabaseOrFile.java
 types[140492550][CopyToDatabaseOrFile] = src/JLS4/CopyToDatabaseOrFile/v1/CopyToDatabaseOrFile.java
+types[140492550][CopyToDatabaseOrFile] = src/JLS4/CopyToDatabaseOrFile/v2/CopyToDatabaseOrFile.java
 types[140492550][Copy] = src/JLS4/Copy/v1/Copy.java
 types[140492550][Copy] = src/JLS4/Copy/v2/Copy.java
-types[140492550][CovarDemo] = src/JLS3/CovarDemo/v2/CovarDemo.java
 types[140492550][CovarDemo] = src/JLS3/CovarDemo/v1/CovarDemo.java
-types[140492550][DMDemo] = src/JLS8/DMDemo/v3/DMDemo.java
+types[140492550][CovarDemo] = src/JLS3/CovarDemo/v2/CovarDemo.java
+types[140492550][DMDemo] = src/JLS8/DMDemo/v1/DMDemo.java
 types[140492550][DMDemo] = src/JLS8/DMDemo/v2/DMDemo.java
+types[140492550][DMDemo] = src/JLS8/DMDemo/v3/DMDemo.java
 types[140492550][DMDemo] = src/JLS8/DMDemo/v4/DMDemo.java
-types[140492550][DMDemo] = src/JLS8/DMDemo/v1/DMDemo.java
 types[140492550][Drawable] = src/JLS8/SMDemo/Drawable.java
 types[140492550][Drivable] = src/JLS8/DMDemo/v1/Drivable.java
 types[140492550][Drivable] = src/JLS8/DMDemo/v2/Drivable.java
 types[140492550][Drivable] = src/JLS8/DMDemo/v3/Drivable.java
 types[140492550][Employee] = src/JLS2/GenDemo/v2/GenDemo.java
+types[140492550][Employee] = src/JLS3/EnForLoopDemo/v1/EnForLoopDemo.java
 types[140492550][Employee] = src/JLS3/GenDemo/v2/GenDemo.java
 types[140492550][Employee] = src/JLS3/GenDemo/v2/GenDemo2.java
-types[140492550][Employee] = src/JLS3/EnForLoopDemo/v1/EnForLoopDemo.java
-types[140492550][EnForLoopDemo] = src/JLS3/EnForLoopDemo/v2/EnForLoopDemo.java
 types[140492550][EnForLoopDemo] = src/JLS3/EnForLoopDemo/v1/EnForLoopDemo.java
-types[140492550][Filter] = src/JLS3/GenDemo/v5/GenDemo5.java
-types[140492550][Filter] = src/JLS3/GenDemo/v5/GenDemo.java
+types[140492550][EnForLoopDemo] = src/JLS3/EnForLoopDemo/v2/EnForLoopDemo.java
 types[140492550][Filter] = src/JLS2/GenDemo/v5/GenDemo.java
-types[140492550][GenDemo.] = src/JLS3/GenDemo/v5/GenDemo5.java
-types[140492550][GenDemo.] = src/JLS3/GenDemo/v5/GenDemo.java
+types[140492550][Filter] = src/JLS3/GenDemo/v5/GenDemo.java
+types[140492550][Filter] = src/JLS3/GenDemo/v5/GenDemo5.java
 types[140492550][GenDemo.] = src/JLS2/GenDemo/v5/GenDemo.java
-types[140492550][GenDemo] = src/JLS2/GenDemo/v2/GenDemo.java
+types[140492550][GenDemo.] = src/JLS3/GenDemo/v5/GenDemo.java
+types[140492550][GenDemo.] = src/JLS3/GenDemo/v5/GenDemo5.java
 types[140492550][GenDemo] = src/JLS2/GenDemo/v1/GenDemo.java
+types[140492550][GenDemo] = src/JLS2/GenDemo/v2/GenDemo.java
+types[140492550][GenDemo] = src/JLS2/GenDemo/v3/GenDemo.java
 types[140492550][GenDemo] = src/JLS2/GenDemo/v4/GenDemo.java
-types[140492550][GenDemo] = src/JLS3/GenDemo/v5/GenDemo5.java
 types[140492550][GenDemo] = src/JLS2/GenDemo/v5/GenDemo.java
+types[140492550][GenDemo] = src/JLS3/GenDemo/v1/GenDemo.java
 types[140492550][GenDemo] = src/JLS3/GenDemo/v1/GenDemo1.java
-types[140492550][GenDemo] = src/JLS3/GenDemo/v3/GenDemo3.java
-types[140492550][GenDemo] = src/JLS3/GenDemo/v4/GenDemo.java
-types[140492550][GenDemo] = src/JLS3/GenDemo/v3/GenDemo.java
 types[140492550][GenDemo] = src/JLS3/GenDemo/v2/GenDemo.java
-types[140492550][GenDemo] = src/JLS3/GenDemo/v5/GenDemo.java
-types[140492550][GenDemo] = src/JLS3/GenDemo/v1/GenDemo.java
 types[140492550][GenDemo] = src/JLS3/GenDemo/v2/GenDemo2.java
+types[140492550][GenDemo] = src/JLS3/GenDemo/v3/GenDemo.java
+types[140492550][GenDemo] = src/JLS3/GenDemo/v3/GenDemo3.java
+types[140492550][GenDemo] = src/JLS3/GenDemo/v4/GenDemo.java
 types[140492550][GenDemo] = src/JLS3/GenDemo/v4/GenDemo4.java
-types[140492550][GenDemo] = src/JLS2/GenDemo/v3/GenDemo.java
+types[140492550][GenDemo] = src/JLS3/GenDemo/v5/GenDemo.java
+types[140492550][GenDemo] = src/JLS3/GenDemo/v5/GenDemo5.java
 types[140492550][HeapPollutionDemo] = src/JLS4/HeapPollutionDemo/HeapPollutionDemo.java
-types[140492550][LambdaDemo.] = src/JLS8/LambdaDemo/v7/LambdaDemo.java
 types[140492550][LambdaDemo.] = src/JLS8/LambdaDemo/v2/LambdaDemo.java
 types[140492550][LambdaDemo.] = src/JLS8/LambdaDemo/v4/LambdaDemo.java
+types[140492550][LambdaDemo.] = src/JLS8/LambdaDemo/v7/LambdaDemo.java
 types[140492550][LambdaDemo] = src/JLS8/LambdaDemo/v1/LambdaDemo.java
-types[140492550][LambdaDemo] = src/JLS8/LambdaDemo/v3/LambdaDemo.java
-types[140492550][LambdaDemo] = src/JLS8/LambdaDemo/v6/LambdaDemo.java
-types[140492550][LambdaDemo] = src/JLS8/LambdaDemo/v7/LambdaDemo.java
 types[140492550][LambdaDemo] = src/JLS8/LambdaDemo/v10/LambdaDemo.java
 types[140492550][LambdaDemo] = src/JLS8/LambdaDemo/v2/LambdaDemo.java
-types[140492550][LambdaDemo] = src/JLS8/LambdaDemo/v9/LambdaDemo.java
+types[140492550][LambdaDemo] = src/JLS8/LambdaDemo/v3/LambdaDemo.java
 types[140492550][LambdaDemo] = src/JLS8/LambdaDemo/v4/LambdaDemo.java
-types[140492550][LambdaDemo] = src/JLS8/LambdaDemo/v8/LambdaDemo.java
 types[140492550][LambdaDemo] = src/JLS8/LambdaDemo/v5/LambdaDemo.java
+types[140492550][LambdaDemo] = src/JLS8/LambdaDemo/v6/LambdaDemo.java
+types[140492550][LambdaDemo] = src/JLS8/LambdaDemo/v7/LambdaDemo.java
+types[140492550][LambdaDemo] = src/JLS8/LambdaDemo/v8/LambdaDemo.java
+types[140492550][LambdaDemo] = src/JLS8/LambdaDemo/v9/LambdaDemo.java
 types[140492550][Light] = src/JLS3/StaticImportsDemo/v1/Light.java
-types[140492550][MRDemo.] = src/JLS8/MRDemo/v3/MRDemo.java
 types[140492550][MRDemo.] = src/JLS8/MRDemo/v2/MRDemo.java
+types[140492550][MRDemo.] = src/JLS8/MRDemo/v3/MRDemo.java
 types[140492550][MRDemo] = src/JLS8/MRDemo/v1/MRDemo.java
+types[140492550][MRDemo] = src/JLS8/MRDemo/v2/MRDemo.java
 types[140492550][MRDemo] = src/JLS8/MRDemo/v3/MRDemo.java
 types[140492550][MRDemo] = src/JLS8/MRDemo/v4/MRDemo.java
 types[140492550][MRDemo] = src/JLS8/MRDemo/v5/MRDemo.java
-types[140492550][MRDemo] = src/JLS8/MRDemo/v2/MRDemo.java
 types[140492550][MRDemo] = src/JLS8/MRDemo/v6/MRDemo.java
 types[140492550][Marble] = src/JLS4/BoxDemo/Marble.java
-types[140492550][MonitorEngine] = src/JLS4/MonitorEngine/v2/MonitorEngine.java
 types[140492550][MonitorEngine] = src/JLS4/MonitorEngine/v1/MonitorEngine.java
+types[140492550][MonitorEngine] = src/JLS4/MonitorEngine/v2/MonitorEngine.java
 types[140492550][PNG] = src/JLS2/AssertDemo/v3/AssertDemo.java
-types[140492550][PaperFactory] = src/JLS3/CovarDemo/v2/CovarDemo.java
 types[140492550][PaperFactory] = src/JLS3/CovarDemo/v1/CovarDemo.java
-types[140492550][Paper] = src/JLS3/CovarDemo/v2/CovarDemo.java
+types[140492550][PaperFactory] = src/JLS3/CovarDemo/v2/CovarDemo.java
 types[140492550][Paper] = src/JLS3/CovarDemo/v1/CovarDemo.java
+types[140492550][Paper] = src/JLS3/CovarDemo/v2/CovarDemo.java
 types[140492550][Planets] = src/JLS4/Planets/Planets.java
-types[140492550][PressureException] = src/JLS4/MonitorEngine/v2/MonitorEngine.java
 types[140492550][PressureException] = src/JLS4/MonitorEngine/v1/MonitorEngine.java
+types[140492550][PressureException] = src/JLS4/MonitorEngine/v2/MonitorEngine.java
 types[140492550][SortInts.] = src/JLS4/SortInts/v1/SortInts.java
 types[140492550][SortInts.] = src/JLS4/SortInts/v2/SortInts.java
 types[140492550][SortInts] = src/JLS4/SortInts/v1/SortInts.java
@@ -121,14 +121,14 @@ types[140492550][SuperException] = src/JLS4/BreakageDemo/BreakageDemo.java
 types[140492550][Switchable] = src/JLS3/StaticImportsDemo/v1/Switchable.java
 types[140492550][TEDemo] = src/JLS3/TEDemo/v1/TEDemo.java
 types[140492550][TEDemo] = src/JLS3/TEDemo/v2/TEDemo.java
-types[140492550][TemperatureException] = src/JLS4/MonitorEngine/v2/MonitorEngine.java
 types[140492550][TemperatureException] = src/JLS4/MonitorEngine/v1/MonitorEngine.java
+types[140492550][TemperatureException] = src/JLS4/MonitorEngine/v2/MonitorEngine.java
+types[140492550][ToDo] = src/JLS3/AnnDemo/v2/ToDo.java
+types[140492550][ToDo] = src/JLS3/AnnDemo/v3/ToDo.java
 types[140492550][ToDo] = src/JLS3/AnnDemo/v4/ToDo.java
+types[140492550][ToDo] = src/JLS3/AnnDemo/v5/ToDo.java
 types[140492550][ToDo] = src/JLS3/AnnProcDemo/ToDo.java
 types[140492550][ToDo] = src/JLS8/RADemo/ToDo.java
-types[140492550][ToDo] = src/JLS3/AnnDemo/v3/ToDo.java
-types[140492550][ToDo] = src/JLS3/AnnDemo/v5/ToDo.java
-types[140492550][ToDo] = src/JLS3/AnnDemo/v2/ToDo.java
 types[140492550][TransientDemo.Transient] = src/JLS2/TransientDemo/Transient.java
 types[140492550][UndLitDemo] = src/JLS4/UndLitDemo/UndLitDemo.java
 types[140492550][UnsafeVarargsDemo2] = src/JLS4/UnsafeVarargsDemo/UnsafeVarargsDemo2.java