Index: d2stacktrace/stacktrace.d
==================================================================
--- d2stacktrace/stacktrace.d
+++ d2stacktrace/stacktrace.d
@@ -31,10 +31,11 @@
 import core.runtime;
 import std.stdio;
 import std.c.stdlib;
 import std.demangle;
 import std.conv;
+import std.path;
 
 extern(Windows){
 	DWORD GetEnvironmentVariableA(LPCSTR lpName, LPSTR pBuffer, DWORD nSize);
 	void RtlCaptureContext(CONTEXT* ContextRecord);
 	typedef LONG function(void*) UnhandeledExceptionFilterFunc;
@@ -335,24 +336,29 @@
 			
 			if(stackframe.AddrPC.Offset != 0){
 				string lineStr = "";
 				Dbghelp.DWORD64 offsetFromSymbol = cast(Dbghelp.DWORD64)0;
 				if( Dbghelp.SymGetSymFromAddr64(hProcess,stackframe.AddrPC.Offset,&offsetFromSymbol,Symbol) == TRUE){
-					char[] symName = new char[strlen(cast(const(char)*)Symbol.Name.ptr)+1];
+					char[] symName = new char[strlen(cast(const(char)*)Symbol.Name.ptr)];
 					memcpy(symName.ptr,Symbol.Name.ptr,symName.length);
 					string symString = "";
 					if(symName[0] == 'D')
 						symString = "_";
 					symString ~= symName;
 
-					string demangeledName = demangle(symString);
-					lineStr ~= demangeledName;
+					string demangledName = demangle(symString);
+					bool isOK = true;
+					for(int i=0; i<demangledName.length; ++i)
+						if( demangledName[i] >= 0x80 )
+							isOK = false;
+					if(isOK)
+						lineStr ~= demangledName;
 
 					DWORD zeichen = 0;
 					if(Dbghelp.SymGetLineFromAddr64(hProcess,stackframe.AddrPC.Offset,&zeichen,&Line) == TRUE){
 						char[] fileName = new char[strlen(Line.FileName)];
-						fileName[] = Line.FileName[0..fileName.length];
+						fileName = std.path.basename( Line.FileName[0..fileName.length] );
 						lineStr = to!string(fileName ~ "::" ~ to!string(Line.LineNumber) ~ "(" ~ to!string(zeichen) ~ ") " ~ lineStr);
 					}
 				}
 				else {
 					lineStr = to!string(cast(ulong)stackframe.AddrPC.Offset);

Index: main.d
==================================================================
--- main.d
+++ main.d
@@ -20,10 +20,14 @@
 	string buf;
 	Value  lastVal;
 	int lineno = 1;
 	int nextlineno = 1;
 	this() { ctx = createGlobalContext(); }
+	this(string filename) {
+		ctx = createGlobalContext();
+		eval(parseFile(filename), ctx, false, "@v");
+	}
 
 	bool tryRun( string s )
 	{
 		scope(failure)
 			{ buf = ""; lineno = nextlineno; }
@@ -54,18 +58,24 @@
 		return true;
 	}
 }
 
 /// Entry point. If args.length==1, invoke REPL.
+/// If args.length==3 && args[1]=="-l" read args[2] and invoke REPL.
 /// Otherwise interpret the argument as a filename.
 void main( string[] args )
 {
 	if( args.length <= 1 )
 	{
 		writeln("Welcome to Polemy 0.1.0");
 		for(auto r = new REPL; r.singleInteraction();) {}
 	}
+	else if( args.length>=3 && args[1]=="-l" )
+	{
+		writeln("Welcome to Polemy 0.1.0");
+		for(auto r = new REPL(args[2]); r.singleInteraction();) {}
+	}
 	else
 	{
 		evalFile(args[1]);
 	}
 }

Index: polemy/_common.d
==================================================================
--- polemy/_common.d
+++ polemy/_common.d
@@ -11,5 +11,6 @@
 public import std.conv : to;
 public import std.bigint;
 public import std.exception;
 public import tricks.tricks;
 public import tricks.test;
+public import std.stdio : writeln; // for debugging...

Index: polemy/eval.d
==================================================================
--- polemy/eval.d
+++ polemy/eval.d
@@ -75,10 +75,11 @@
 		throw genex!RuntimeException(pos, "type mismatch in if");
 	}));
 	ctx.set("_isint", "@v", native( (Value v){return new IntValue(BigInt(cast(IntValue)v is null ? 0 : 1));} ));
 	ctx.set("_isstr", "@v", native( (Value v){return new IntValue(BigInt(cast(StrValue)v is null ? 0 : 1));} ));
 	ctx.set("_isfun", "@v", native( (Value v){return new IntValue(BigInt(cast(FunValue)v is null ? 0 : 1));} ));
+	ctx.set("_isundefined", "@v", native( (Value v){return new IntValue(BigInt(cast(UndValue)v is null ? 0 : 1));} ));
 	return ctx;
 }
 
 /// Entry point of this module
 
@@ -163,19 +164,38 @@
 			}
 			throw genex!RuntimeException(e.pos, "Non-funcion is applied");
 		},
 		(FunLiteral e)
 		{
-			// funvalue need not be rised
-			return new FunValue(delegate Value(immutable LexPosition pos, string lay, Value[] args){
+			Value[Value[]][Layer] memo;
+
+			// funvalue need not be rised
+			// no, need to be rised !!  suppose @t(fib)("int")
+			return new FunValue(delegate Value(immutable LexPosition pos, string lay, Value[] args){
+				// TODO: only auto raised ones need memo? no?
+				// auto memoization
+				if( lay != "@v" )
+				{
+					if( auto memolay = lay in memo )
+						if( auto pv = args in *memolay )
+							return *pv;
+					memo[lay][args] = (cast(FunValue)ctx.get(lay, "(system)", e.pos)).call(e.pos, "@v", 
+						[new UndValue]
+					);
+				}
+				
 				if( e.params.length != args.length )
 					throw genex!RuntimeException(e.pos, sprintf!"Argument Number Mismatch (%d required but %d given)"
 						(e.params.length, args.length));
 				Table ctxNeo = new Table(ctx, Table.Kind.NotPropagateSet);
 				foreach(i,p; e.params)
 					ctxNeo.set(p.name, lay, args[i]);
-				return eval(e.funbody, ctxNeo, true, lay);
+				auto v = eval(e.funbody, ctxNeo, true, lay);
+				// auto memoization
+				if( lay != "@v" )
+					memo[lay][args] = v;
+				return v;
 			});
 		},
 		delegate Value (AST e)
 		{
 			throw genex!RuntimeException(e.pos, sprintf!"Unknown Kind of Expression %s"(typeid(e)));

Index: polemy/value.d
==================================================================
--- polemy/value.d
+++ polemy/value.d
@@ -43,10 +43,16 @@
 
 	mixin SimpleConstructor;
 	alias data call;
 	override string toString() const { return sprintf!"(function:%s:%s)"(data.ptr,data.funcptr); }
 }
+
+class UndValue : Value
+{
+	mixin SimpleClass;
+	override string toString() const { return "<undefined>"; }
+}
 
 /// Layer ID
 
 alias string Layer;
 
@@ -68,15 +74,18 @@
 		data[i][lay] = v;
 	}
 
 	Value get(string i, Layer lay, in LexPosition pos=null)
 	{
-		if( i in data )
+		if( i in data ) {
+			if( lay !in data[i] )
+				throw genex!RuntimeException(pos, sprintf!"variable %s is not set in layer %s"(i,lay));
 			return data[i][lay];
+		}
 		if( prototype is null )
 			throw new RuntimeException(pos, sprintf!"variable %s not found"(i));
-		return prototype.get(i, lay);
+		return prototype.get(i, lay, pos);
 	}
 
 private:
 	Table                prototype;
 	Kind                 kind;

ADDED   sample/type.pmy
Index: sample/type.pmy
==================================================================
--- sample/type.pmy
+++ sample/type.pmy
@@ -0,0 +1,28 @@
+@@type = fun(x){
+  if( _isint(x) ) { "int" }
+  else { if( _isstr(x) ) { "str" }
+  else { if( _isfun(x) ) { x }
+  else { if( _isundefined(x) ) { "undefined" }
+  else { "any" }}}}
+};
+
+def binop(a,b,c) {
+  fun(x,y){@v(
+    if( @type(x)=="undefined" || @type(y)=="undefined" ) { "undefined" } else {
+      if( @type(x)==a && @type(y)==b ) { c } else { "error" }
+    }
+  )}
+};
+
+@type "+" = binop("int", "int", "int");
+@type "-" = binop("int", "int", "int");
+@type "<" = binop("int", "int", "int");
+@type ">" = binop("int", "int", "int");
+
+def mergeType(a,b) {
+  if( a == "undefined" ) { if(b=="undefined"){"error"}else{b} } else { a }
+};
+
+@type "if" = fun(c,t,e) {@v(
+ if(@type(c)=="int" ) { mergeType(@type(t()), @type(e())) } else { "error" }
+)};