Improve ast classes and visitor.

grammar/LuaParser.jj

@@ -47,16 +47,16 @@ public class LuaParser {
     parser.Chunk();
   }
   
-  private static VarExp assertvarexp(PrimaryExp pe) throws ParseException {
+  private static Exp.VarExp assertvarexp(Exp.PrimaryExp pe) throws ParseException {
   	if (!pe.isvarexp()) 
 		throw new ParseException("exptected variable");
-	return (VarExp) pe; 
+	return (Exp.VarExp) pe; 
   }
   
-  private static FuncCall assertfunccall(PrimaryExp pe) throws ParseException {
+  private static Exp.FuncCall assertfunccall(Exp.PrimaryExp pe) throws ParseException {
   	if (!pe.isfunccall()) 
 		throw new ParseException("expected function call");
-	return (FuncCall) pe; 
+	return (Exp.FuncCall) pe; 
   }
 }
 
@@ -230,7 +230,7 @@ Stat LastStat():
 
 Stat ExprStat():
 {
-	PrimaryExp pe;
+	Exp.PrimaryExp pe;
 	Stat as=null;
 }
 {
@@ -238,20 +238,20 @@ Stat ExprStat():
 	{ return as==null? Stat.functioncall(assertfunccall(pe)): as; }
 }
 
-Stat Assign(VarExp v0):
+Stat Assign(Exp.VarExp v0):
 {
-	List<VarExp> vl = new ArrayList<VarExp>();
+	List<Exp.VarExp> vl = new ArrayList<Exp.VarExp>();
 	vl.add(v0);
-	VarExp ve;
+	Exp.VarExp ve;
 	List<Exp> el;
 }
 {
 	( "," ve=VarExp() { vl.add(ve); } )* "=" el=ExpList() { return Stat.assignment(vl,el); }
 }
 
-VarExp VarExp():
+Exp.VarExp VarExp():
 {
-	PrimaryExp pe;
+	Exp.PrimaryExp pe;
 }
 {
 	pe=PrimaryExp() { return assertvarexp(pe); }	
@@ -269,36 +269,35 @@ FuncName FuncName():
 			{return fn;}
 }
 
-PrimaryExp PrefixExp():
+Exp.PrimaryExp PrefixExp():
 {
 	Token n;
 	Exp e;
 }
 {
-	n=<NAME>			{ return PrimaryExp.nameprefix(n.image); }
-|	"(" e=Exp() ")"		{ return PrimaryExp.parensprefix(e); }
+	n=<NAME>			{ return Exp.nameprefix(n.image); }
+|	"(" e=Exp() ")"		{ return Exp.parensprefix(e); }
 }
 
-PrimaryExp PrimaryExp(): 
+Exp.PrimaryExp PrimaryExp(): 
 {	
-	PrimaryExp pe;
-	PostfixOp po; 
+	Exp.PrimaryExp pe;
 }
 {
-	pe=PrefixExp() ( LOOKAHEAD(2) po=PostfixOp() {pe=pe.append(po);} )* { return pe; }
+	pe=PrefixExp() ( LOOKAHEAD(2) pe=PostfixOp(pe) )* { return pe; }
 }
 
-PostfixOp PostfixOp():
+Exp.PrimaryExp PostfixOp(Exp.PrimaryExp lhs):
 {
 	Token n;
 	Exp e;
 	FuncArgs a;
 }
 {
-	"." n=<NAME>				{ return PostfixOp.fieldop(n.image); } 
-|	"[" e=Exp() "]"				{ return PostfixOp.indexop(e); }
-|	":" n=<NAME> a=FuncArgs()	{ return PostfixOp.methodop(n.image,a); } 
-|	a=FuncArgs() 				{ return PostfixOp.functionop(a); }
+	"." n=<NAME>				{ return Exp.fieldop(lhs, n.image); } 
+|	"[" e=Exp() "]"				{ return Exp.indexop(lhs, e); }
+|	":" n=<NAME> a=FuncArgs()	{ return Exp.methodop(lhs, n.image,a); } 
+|	a=FuncArgs() 				{ return Exp.functionop(lhs, a); }
 }
 
 FuncArgs FuncArgs():
@@ -403,30 +402,30 @@ ParList ParList():
 TableConstructor TableConstructor():
 {
 	TableConstructor tc = new TableConstructor();
-	List<Field> fl = null;
+	List<TableField> fl = null;
 }
 {
 	"{" ( fl=FieldList() {tc.fields=fl;} )? "}" { return tc; }
 }
 
-List<Field> FieldList():
+List<TableField> FieldList():
 {
-	List<Field> fl = new ArrayList<Field>();
-	Field f;
+	List<TableField> fl = new ArrayList<TableField>();
+	TableField f;
 }
 {
 	f=Field() {fl.add(f);} (LOOKAHEAD(2) FieldSep() f=Field() {fl.add(f);})* (FieldSep())? { return fl; }
 }
 
-Field Field():
+TableField Field():
 {
 	Token name;
 	Exp exp,rhs;
 }
 {
-	"[" exp=Exp() "]" "=" rhs=Exp()         { return Field.keyedField(exp,rhs); }
-|	LOOKAHEAD(2) name=<NAME> "=" rhs=Exp()  { return Field.namedField(name.image,rhs); }
-|	rhs=Exp()                               { return Field.listField(rhs); }
+	"[" exp=Exp() "]" "=" rhs=Exp()         { return TableField.keyedField(exp,rhs); }
+|	LOOKAHEAD(2) name=<NAME> "=" rhs=Exp()  { return TableField.namedField(name.image,rhs); }
+|	rhs=Exp()                               { return TableField.listField(rhs); }
 }
 
 void FieldSep():

src/jse/org/luaj/vm2/ast/Exp.java

@@ -51,6 +51,142 @@ public class Exp {
 		return new AnonFuncDef(funcbody);
 	}
 
+	/** foo */
+	public static NameExp nameprefix(String name) {
+		return new NameExp(name);
+	}
+
+	/** ( foo.bar ) */
+	public static ParensExp parensprefix(Exp exp) {
+		return new ParensExp(exp);
+	}
+
+	/** foo[exp] */
+	public static IndexExp indexop(PrimaryExp lhs, Exp exp) {
+		return new IndexExp(lhs, exp);
+	}
+
+	/** foo.bar */
+	public static FieldExp fieldop(PrimaryExp lhs, String name) {
+		return new FieldExp(lhs, name);
+	}
+
+	/** foo(2,3) */
+	public static FuncCall functionop(PrimaryExp lhs, FuncArgs args) {
+		return new FuncCall(lhs, args);
+	}
+
+	/** foo:bar(4,5) */
+	public static MethodCall methodop(PrimaryExp lhs, String name, FuncArgs args) {
+		return new MethodCall(lhs, name, args);
+	}
+
+	public boolean isvarexp() {
+		return false;
+	}
+
+	public boolean isfunccall() {
+		return false;
+	}
+
+	abstract public static class PrimaryExp extends Exp {
+		public boolean isvarexp() {
+			return false;
+		}
+		public boolean isfunccall() {
+			return false;
+		}
+	}
+
+	abstract public static class VarExp extends PrimaryExp {
+		public boolean isvarexp() {
+			return true;
+		}
+	}
+	
+	public static class NameExp extends VarExp {
+		public final Name name;
+		public NameExp(String name) {
+			this.name = new Name(name);
+		}
+		
+		public void accept(Visitor visitor) {
+			visitor.visit(this);
+		}
+	}
+	
+	public static class ParensExp extends PrimaryExp {
+		public final Exp exp;
+		public ParensExp(Exp exp) {
+			this.exp = exp;
+		}
+		
+		public void accept(Visitor visitor) {
+			visitor.visit(this);
+		}
+	}
+	
+	public static class FieldExp extends VarExp {
+		public final PrimaryExp lhs;
+		public final Name name;
+		public FieldExp(PrimaryExp lhs, String name) {
+			this.lhs = lhs;
+			this.name = new Name(name);
+		}
+		
+		public void accept(Visitor visitor) {
+			visitor.visit(this);
+		}
+	}
+	
+	public static class IndexExp extends VarExp {
+		public final PrimaryExp lhs;
+		public final Exp exp;
+		public IndexExp(PrimaryExp lhs, Exp exp) {
+			this.lhs = lhs;
+			this.exp = exp;
+		}
+		
+		public void accept(Visitor visitor) {
+			visitor.visit(this);
+		}
+	}
+	
+	public static class FuncCall extends PrimaryExp {
+		public final PrimaryExp lhs;
+		public final FuncArgs args;
+		
+		public FuncCall(PrimaryExp lhs, FuncArgs args) {
+			this.lhs = lhs;
+			this.args = args;
+		}
+
+		public boolean isfunccall() {
+			return true;
+		}
+		
+		public void accept(Visitor visitor) {
+			visitor.visit(this);
+		}
+	}
+	
+	public static class MethodCall extends FuncCall {
+		public final String name;
+		
+		public MethodCall(PrimaryExp lhs, String name, FuncArgs args) {
+			super(lhs, args);
+			this.name = new String(name);
+		}
+
+		public boolean isfunccall() {
+			return true;
+		}
+		
+		public void accept(Visitor visitor) {
+			visitor.visit(this);
+		}
+	}
+
 	public static class Constant extends Exp {
 		public final LuaValue value;
 		public Constant(LuaValue value) {

src/jse/org/luaj/vm2/ast/FuncCall.java

@@ -1,30 +0,0 @@
-/*******************************************************************************
-* Copyright (c) 2010 Luaj.org. All rights reserved.
-*
-* Permission is hereby granted, free of charge, to any person obtaining a copy
-* of this software and associated documentation files (the "Software"), to deal
-* in the Software without restriction, including without limitation the rights
-* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-* copies of the Software, and to permit persons to whom the Software is
-* furnished to do so, subject to the following conditions:
-*
-* The above copyright notice and this permission notice shall be included in
-* all copies or substantial portions of the Software.
-* 
-* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-* THE SOFTWARE.
-******************************************************************************/
-package org.luaj.vm2.ast;
-
-public class FuncCall extends PrimaryExp {
-
-	public void accept(Visitor visitor) {
-		visitor.visit(this);
-	}
-
-}

src/jse/org/luaj/vm2/ast/PostfixOp.java

@@ -1,61 +0,0 @@
-/*******************************************************************************
-* Copyright (c) 2010 Luaj.org. All rights reserved.
-*
-* Permission is hereby granted, free of charge, to any person obtaining a copy
-* of this software and associated documentation files (the "Software"), to deal
-* in the Software without restriction, including without limitation the rights
-* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-* copies of the Software, and to permit persons to whom the Software is
-* furnished to do so, subject to the following conditions:
-*
-* The above copyright notice and this permission notice shall be included in
-* all copies or substantial portions of the Software.
-* 
-* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-* THE SOFTWARE.
-******************************************************************************/
-package org.luaj.vm2.ast;
-
-public class PostfixOp {
-
-	/** foo[exp] */
-	public static PostfixOp indexop(Exp e) {
-		// TODO Auto-generated method stub
-		return null;
-	}
-
-	/** foo.name */
-	public static PostfixOp fieldop(String name) {
-		// TODO Auto-generated method stub
-		return null;
-	}
-
-	/** foo:name(args) */
-	public static PostfixOp methodop(String name, FuncArgs args) {
-		// TODO Auto-generated method stub
-		return null;
-	}
-
-	/** foo(args) */
-	public static PostfixOp functionop(FuncArgs a) {
-		// TODO Auto-generated method stub
-		return null;
-	}
-
-	public boolean isvarop() {
-		return false;
-	}
-
-	public boolean isfunccall() {
-		return false;
-	}
-
-	public void accept(Visitor visitor) {
-		visitor.visit(this);
-	}
-}

src/jse/org/luaj/vm2/ast/PrimaryExp.java

@@ -1,57 +0,0 @@
-/*******************************************************************************
-* Copyright (c) 2010 Luaj.org. All rights reserved.
-*
-* Permission is hereby granted, free of charge, to any person obtaining a copy
-* of this software and associated documentation files (the "Software"), to deal
-* in the Software without restriction, including without limitation the rights
-* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-* copies of the Software, and to permit persons to whom the Software is
-* furnished to do so, subject to the following conditions:
-*
-* The above copyright notice and this permission notice shall be included in
-* all copies or substantial portions of the Software.
-* 
-* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-* THE SOFTWARE.
-******************************************************************************/
-package org.luaj.vm2.ast;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class PrimaryExp extends Exp {
-
-	List<PostfixOp> ops;
-	
-	public static PrimaryExp nameprefix(String image) {
-		return null;
-	}
-
-	public static PrimaryExp parensprefix(Exp e) {
-		return null;
-	}
-
-	public PrimaryExp append(PostfixOp op) {	
-		if ( ops == null )
-			ops = new ArrayList<PostfixOp>();
-		ops.add( op );
-		return this;
-	}
-
-	public boolean isvarexp() {
-		return ops != null && ops.get(ops.size()-1).isvarop(); 
-	}
-
-	public boolean isfunccall() {
-		return ops != null && ops.get(ops.size()-1).isfunccall(); 
-	}
-
-	public void accept(Visitor visitor) {
-		visitor.visit(this);
-	}
-}

src/jse/org/luaj/vm2/ast/Stat.java

@@ -47,11 +47,11 @@ public class Stat {
 		return new Return(exps);
 	}
 
-	public static Stat assignment(List<VarExp> vars, List<Exp> exps) {
+	public static Stat assignment(List<Exp.VarExp> vars, List<Exp> exps) {
 		return new Assign(vars,exps);
 	}
 
-	public static Stat functioncall(FuncCall funccall) {
+	public static Stat functioncall(Exp.FuncCall funccall) {
 		return new FuncCallStat(funccall);
 	}
 
@@ -80,10 +80,10 @@ public class Stat {
 	}
 
 	public static class Assign extends Stat {
-		public final List<VarExp> vars;
+		public final List<Exp.VarExp> vars;
 		public final List<Exp> exps;
 		
-		public Assign(List<VarExp> vars, List<Exp> exps) {
+		public Assign(List<Exp.VarExp> vars, List<Exp> exps) {
 			this.vars = vars;
 			this.exps = exps;
 		}
@@ -136,8 +136,8 @@ public class Stat {
 	}
 
 	public static class FuncCallStat extends Stat {
-		public final FuncCall funccall;
-		public FuncCallStat(FuncCall funccall) {
+		public final Exp.FuncCall funccall;
+		public FuncCallStat(Exp.FuncCall funccall) {
 			this.funccall = funccall;
 		}
 

src/jse/org/luaj/vm2/ast/Str.java

@@ -57,7 +57,7 @@ public class Str {
 		try {
 			return s.getBytes("UTF8");
 		} catch ( Exception e ) {
-			throw new RuntimeException("utf8 nto found: "+e);
+			throw new RuntimeException("utf8 not found: "+e);
 		}
 	}
 }

src/jse/org/luaj/vm2/ast/TableConstructor.java

@@ -24,7 +24,7 @@ package org.luaj.vm2.ast;
 import java.util.List;
 
 public class TableConstructor extends Exp {
-	public List<Field> fields;
+	public List<TableField> fields;
 
 	public void accept(Visitor visitor) {
 		visitor.visit(this);

src/jse/org/luaj/vm2/ast/TableField.java

@@ -21,28 +21,28 @@
 ******************************************************************************/
 package org.luaj.vm2.ast;
 
-public class Field {
+public class TableField {
 
 	public final Exp index;
 	public final String name;
 	public final Exp rhs;
 	
-	public Field(Exp index, String name, Exp rhs) {
+	public TableField(Exp index, String name, Exp rhs) {
 		this.index = index;
 		this.name = name;
 		this.rhs = rhs;
 	}
 	
-	public static Field keyedField(Exp index, Exp rhs) {
-		return new Field(index, null, rhs);
+	public static TableField keyedField(Exp index, Exp rhs) {
+		return new TableField(index, null, rhs);
 	}
 
-	public static Field namedField(String name, Exp rhs) {
-		return new Field(null, name, rhs);
+	public static TableField namedField(String name, Exp rhs) {
+		return new TableField(null, name, rhs);
 	}
 
-	public static Field listField(Exp rhs) {
-		return new Field(null, null, rhs);
+	public static TableField listField(Exp rhs) {
+		return new TableField(null, null, rhs);
 	}
 
 	public void accept(Visitor visitor) {

src/jse/org/luaj/vm2/ast/VarExp.java

@@ -1,28 +0,0 @@
-/*******************************************************************************
-* Copyright (c) 2010 Luaj.org. All rights reserved.
-*
-* Permission is hereby granted, free of charge, to any person obtaining a copy
-* of this software and associated documentation files (the "Software"), to deal
-* in the Software without restriction, including without limitation the rights
-* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-* copies of the Software, and to permit persons to whom the Software is
-* furnished to do so, subject to the following conditions:
-*
-* The above copyright notice and this permission notice shall be included in
-* all copies or substantial portions of the Software.
-* 
-* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-* THE SOFTWARE.
-******************************************************************************/
-package org.luaj.vm2.ast;
-
-public class VarExp extends PrimaryExp {
-	public void accept(Visitor visitor) {
-		visitor.visit(this);
-	}
-}

src/jse/org/luaj/vm2/ast/Visitor.java

@@ -1,64 +1,144 @@
 package org.luaj.vm2.ast;
 
+import java.util.List;
+
 abstract public class Visitor {
 	public void visit(Chunk chunk) { 
 		chunk.block.accept(this); 
 	};
 	public void visit(Block block) {
 		if ( block.stats != null )
-			for ( Stat s : block.stats )
-				s.accept( this );
+			for ( Stat s: block.stats )
+				s.accept(this);
 	};
-	public void visit(Stat.Assign assign) {
+	public void visit(Stat.Assign stat) {
+		visitVars(stat.vars);
+		visitExps(stat.exps);
 	}
 	public void visit(Stat.Break breakstat) {
 	}
 	public void visit(Stat.FuncCallStat stat) {
+		stat.funccall.accept(this);
 	}
 	public void visit(Stat.FuncDef stat) {
+		stat.body.accept(this);
 	}
 	public void visit(Stat.GenericFor stat) {
+		visitNames(stat.names);
+		visitExps(stat.exps);
+		stat.block.accept(this);
 	}
 	public void visit(Stat.IfThenElse stat) {
+		stat.ifexp.accept(this);
+		stat.ifblock.accept(this);
+		for ( int i=0, n=stat.elseifblocks.size(); i<n; i++ ) {
+			stat.elseifexps.get(i).accept(this);
+			stat.elseifblocks.get(i).accept(this);
+		}
+		visit( stat.elseblock );
 	}
 	public void visit(Stat.LocalAssign stat) {
+		visitNames(stat.names);
+		visitExps(stat.values);
 	}
 	public void visit(Stat.LocalFuncDef stat) {
+		visit(stat.name);
+		stat.body.accept(this);
 	}
 	public void visit(Stat.NumericFor stat) {
+		visit(stat.name);
+		stat.initial.accept(this);
+		stat.step.accept(this);
+		stat.limit.accept(this);
+		stat.block.accept(this);
 	}
 	public void visit(Stat.RepeatUntil stat) {
+		stat.block.accept(this);
+		stat.exp.accept(this);
 	}
 	public void visit(Stat.Return stat) {
+		visitExps(stat.values);
 	}
 	public void visit(Stat.WhileDo stat) {
+		stat.exp.accept(this);
+		stat.block.accept(this);
 	}
-	public void visit(FuncCall funcCall) {
+	public void visit(FuncBody body) {
+		body.parlist.accept(this);
+		body.block.accept(this);
 	}
-	public void visit(FuncBody funcBody) {
+	public void visit(FuncArgs args) {
+		visitExps(args.exps);
 	}
-	public void visit(FuncArgs funcArgs) {
-	}
-	public void visit(Field field) {
-	}
-	public void visit(Exp exp) {
+	public void visit(TableField field) {
+		if ( field.name != null );
+			visit( field.name );
+		if ( field.index != null )
+			field.index.accept(this);
+		field.rhs.accept(this);
 	}
 	public void visit(Exp.AnonFuncDef exp) {
+		exp.funcbody.accept(this);
 	}
 	public void visit(Exp.BinopExp exp) {
+		exp.lhs.accept(this);
+		exp.rhs.accept(this);
 	}
 	public void visit(Exp.Constant exp) {
 	}
+	public void visit(Exp.FieldExp exp) {
+		exp.lhs.accept(this);
+		visit(exp.name);
+	}
+	public void visit(Exp.FuncCall exp) {
+		exp.lhs.accept(this);
+		exp.args.accept(this);
+	}
+	public void visit(Exp.IndexExp exp) {
+		exp.lhs.accept(this);
+		exp.exp.accept(this);
+	}
+	public void visit(Exp.MethodCall exp) {
+		exp.lhs.accept(this);
+		visit(exp.name);
+		exp.args.accept(this);
+	}
+	public void visit(Exp.NameExp exp) {
+		visit(exp.name);
+	}
+	public void visit(Exp.ParensExp exp) {
+		exp.exp.accept(this);
+	}
 	public void visit(Exp.UnopExp exp) {
+		exp.rhs.accept(this);
 	}
 	public void visit(Exp.VarargsExp exp) {
 	}
-	public void visit(PrimaryExp exp) {
+	public void visit(ParList pars) {
+		visitNames(pars.names);
 	}
-	public void visit(ParList parList) {
+	public void visit(TableConstructor table) {
+		if( table.fields != null)
+			for ( TableField f: table.fields )
+				f.accept(this);
 	}
-	public void visit(PostfixOp postfixOp) {
+	public void visitVars(List<Exp.VarExp> vars) {
+		if ( vars != null )
+			for ( Exp.VarExp v: vars )
+				v.accept(this);
 	}
-	public void visit(VarExp exp) {
+	public void visitExps(List<Exp> exps) {
+		if ( exps != null )
+			for ( Exp e: exps )
+				e.accept(this);
+	}
+	public void visitNames(List<Name> names) {
+		if ( names != null )
+			for ( Name n: names )
+				visit(n);
+	}
+	private void visit(Name name) {
+	}
+	private void visit(String name) {
 	}
 }