Index: polemy/eval.d
==================================================================
--- polemy/eval.d
+++ polemy/eval.d
@@ -52,10 +52,19 @@
 		foreach(a; args)
 			write(a);
 		writeln("");
 		return new UndefinedValue;
 	}));
+	ctx.add("if", new FunValue(delegate Value(immutable LexPosition pos, Value[] args){
+		if( args.length != 3 )
+			throw new PolemyRuntimeException("if takes three arguments!! ["~to!string(pos)~"]");
+		if( auto x = cast(IntValue)args[0] )
+		if( auto ft = cast(FunValue)args[1] )
+		if( auto fe = cast(FunValue)args[2] )
+			return (x.data == 0 ? fe : ft).call(pos,[]);
+		throw new PolemyRuntimeException("type mismatch in if ["~to!string(pos)~"]");
+	}));
 	return ctx;
 }
 
 Tuple!(Value,"val",Context,"ctx") evalString(T...)(T params)
 {
@@ -181,5 +190,19 @@
 unittest
 {
 	evalString(`print("Hello, world!");`);
 	evalString(`print(fun(){});`);
 }
+unittest
+{
+	evalString(`var fac = fun(x){
+		1;
+	};
+	print(fac(3));`);
+	evalString(`var fac = fun(x){
+		if(x)
+			{ x*fac(x-1); }
+		else
+			{ 1; };
+	};
+	print(fac(10));`);
+}

Index: polemy/parse.d
==================================================================
--- polemy/parse.d
+++ polemy/parse.d
@@ -53,12 +53,22 @@
 		this.lex = lex;
 	}
 
 	Program parseProgram()
 	{
+		Program p = parseStatements();
+		if( !lex.empty ) {
+			auto e = ParserException.create(lex, "cannot reach eof");
+			throw e;
+		}
+		return p;
+	}
+
+	Program parseStatements()
+	{
 		Program p;
-		while( !lex.empty )
+		while( !lex.empty && (lex.front.kind!=Token.Kind.identifier || lex.front.str!="}") )
 			p ~= parseStatement();
 		return p;
 	}
 	
 	Statement parseStatement()
@@ -185,10 +195,33 @@
 		{
 			auto e = parseE();
 			eat(")", "after parenthesized expression");
 			return e;
 		}
+		if( tryEat("if") )
+		{
+			eat("(", "after if");
+			auto cond = parseE();
+			eat(")", "after if condition");
+			auto thenPos = lex.front.pos;
+			eat("{", "after if condition");
+			Statement[] th = parseStatements();
+			eat("}", "after if-then body");
+			Statement[] el;
+			auto elsePos = lex.front.pos;
+			if( tryEat("else") ) {
+				eat("{", "after else");
+				el = parseStatements();
+				eat("}", "after else body");
+			}
+			return new FuncallExpression(pos, 
+				new VarExpression(pos, "if"),
+				cond,
+				new FunLiteralExpression(thenPos, [], th),
+				new FunLiteralExpression(elsePos, [], el)
+			);
+		}
 
 		if( tryEat("fun") )
 		{
 			eat("(", "after fun");
 			string[] params;
@@ -312,6 +345,19 @@
 }
 unittest
 {
 	auto p = parserFromString(`var x = 1; var f = fun(){x=x+1;}; f(); f(); x;`);
 	Program prog = p.parseProgram();
+}
+
+unittest
+{
+	auto p = parserFromString(`if(x<2){1;}else{x;};`);
+	Program prog = p.parseProgram();
+	assert( prog[0] == new ExprStatement(null, new FuncallExpression(null,
+		new VarExpression(null, "if"),
+		new FuncallExpression(null, new VarExpression(null,"<"), new VarExpression(null,"x"),
+			new IntLiteralExpression(null, BigInt(2))),
+		new FunLiteralExpression(null, [], [new ExprStatement(null, new IntLiteralExpression(null, BigInt(1)))]),
+		new FunLiteralExpression(null, [], [new ExprStatement(null, new VarExpression(null, "x"))])
+		)));		
 }

Index: polemy/runtime.d
==================================================================
--- polemy/runtime.d
+++ polemy/runtime.d
@@ -29,12 +29,11 @@
 {
 	BigInt data;
 	mixin SimpleConstructor;
 	mixin SimpleCompare;
 	override string toString() const {
-		const(char)[] cs; data.toString((const(char)[] s){cs=s;}, null);
-		return to!string(cs);
+		return std.bigint.toDecimalString(cast(BigInt)data);
 	}
 }
 
 class StrValue : Value
 {