@@ -50,51 +50,94 @@
 	Value invoke(in LexPosition pos, Layer lay, Table ctx);
 }
 
 import polemy.eval; // circular...
+version = MacroCache;
+//version = AutoMemoization;
+//version = AutoRerun;
 
 ///
 class UserDefinedFunValue : FunValue
 {
 	FunLiteral ast;
 	Table      defCtx;
+
+	this(FunLiteral ast, Table defCtx) { this.ast=ast; this.defCtx=defCtx; }
+	override string toString() const { return sprintf!"(function:%x:%x)"(cast(void*)ast, cast(void*)defCtx); }
+	override bool opEquals(Object rhs_) const /// member-by-member equality
+	{
+		if( auto rhs = cast(typeof(this))rhs_ )
+			return this.ast==rhs.ast && this.defCtx==rhs.defCtx;
+		assert(false, sprintf!"Cannot compare %s with %s"(typeid(this), typeid(rhs_)));
+	}
+	override hash_t toHash() const /// member-by-member hash
+	{
+		return typeid(this.ast).getHash(&this.ast) + typeid(this.defCtx).getHash(&this.defCtx);
+	}
+	override int opCmp(Object rhs_) /// member-by-member compare
+	{
+		if( auto rhs = cast(typeof(this))rhs_ )
+		{
+			if(auto i = this.ast.opCmp(rhs.ast))
+				return i;
+			return this.defCtx.opCmp(rhs.defCtx);
+		}
+		assert(false, sprintf!"Cannot compare %s with %s"(typeid(this), typeid(rhs_)));
+	}
+
+	private AST preprocessed_funbody;
+	private Value[Value[]][Layer] memo;
+
 	override const(Parameter[]) params() { return ast.params; }
 	override Table definitionContext() { return defCtx; }
 	override Value invoke(in LexPosition pos, Layer lay, Table ctx)
 	{
 		// TODO: only auto raised ones need memo? no?
-		// auto memoization
-/*
-		if( lay != ValueLayer && lay != MacroLayer )
+		// how can we integrate re-run ??
+		version(AutoMemoization)
 		{
-			if( auto memolay = lay in memo )
-				if( auto pv = args in *memolay )
-					return *pv;
-			memo[lay][args] = lift(e.pos,new UndValue,lay,ctx);
+			Value[] memokey;
+			if( lay != ValueLayer && lay != MacroLayer )
+			{
+				foreach(i,p; ast.params)
+					memokey ~= ctx.get(p.name, lay); // lay?
+				if( auto memolay = lay in memo )
+					if( auto pv = memokey in *memolay )
+						return *pv;
+				memo[lay][memokey] = lift(ast.pos,new UndValue,lay,ctx);
+			}
 		}
-				
-*/
+
 		// @macro run!!!
 		if( lay == MacroLayer )
 			return macroEval(ast.funbody, ctx, false);
-/*TODO memo*/ AST macroMemo;
-		if( macroMemo is null ) {
-			// .prototype!, forced macro cannot access parameters
-			ctx.kill = true; scope(exit)ctx.kill=false;
-			auto tbl = macroEval(ast.funbody, ctx, true);
-			macroMemo = tableToAST(ValueLayer,tbl);
+
+		version(MacroCache) {
+			if( preprocessed_funbody is null ) {
+				// .prototype!, forced macro cannot access parameters
+				ctx.kill = true; scope(exit)ctx.kill=false;
+				preprocessed_funbody = tableToAST(ValueLayer,macroEval(ast.funbody, ctx, true));
+			}
+		} else {
+			if( preprocessed_funbody is null ) {
+				// .prototype!, forced macro cannot access parameters
+				ctx.kill = true; scope(exit)ctx.kill=false;
+				preprocessed_funbody = tableToAST(ValueLayer,macroEval(ast.funbody, ctx, true));
+			}
 		}
-		auto v = eval(macroMemo, ctx, true, lay);
 
-		//auto v = eval(e.funbody, ctxNeo, true, lay);
-		// auto memoization
-//		if( lay != ValueLayer && lay != MacroLayer )
-//			memo[lay][args] = v;
+		auto v = eval(preprocessed_funbody, ctx, true, lay);
+		version(AutoMemoization)
+		{
+			if( lay != ValueLayer && lay != MacroLayer )
+			{
+				memo[lay][memokey] = v;
+				version(AutoReRun)
+				memo[lay][memokey] = eval(preprocessed_funbody, ctx, true, lay); // re-Run!!
+			}
+		}
 		return v;
 	}
-
-	mixin SimpleClass;
-	override string toString() const { return sprintf!"(function:%x:%x)"(cast(void*)ast, cast(void*)defCtx); }
 }
 
 ///
 abstract class NativeFunValue : FunValue
@@ -170,15 +213,15 @@
 	{
 		if( i in data ) {
 			// [TODO] consider forwarding to proto also in this case
 			if( lay !in data[i] )
-				throw genex!RuntimeException(pos, sprintf!"variable %s is not set in layer %s"(i,lay));
+				throw genex!RuntimeException(pos, sprintf!"'%s' is not set in layer %s"(i,lay));
 			if(kill)
-				throw genex!RuntimeException(pos, sprintf!"variable %s is killed in macro"(i));
+				throw genex!RuntimeException(pos, sprintf!"'%s' is killed in macro"(i));
 			return data[i][lay];
 		}
 		if( prototype is null )
-			throw new RuntimeException(pos, sprintf!"variable %s not found"(i));
+			throw new RuntimeException(pos, sprintf!"'%s' not found"(i));
 		return prototype.get(i, lay, pos);
 	}
 
 	T access(T,S...)( Layer lay, string path, S rest )