--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/luan/interp/LuaParser.java	Mon Nov 19 09:49:06 2012 +0000
@@ -0,0 +1,120 @@
+package luan.interp;
+
+import java.util.Scanner;
+import org.parboiled.BaseParser;
+import org.parboiled.Parboiled;
+import org.parboiled.Rule;
+import org.parboiled.parserunners.ReportingParseRunner;
+import org.parboiled.support.ParsingResult;
+import org.parboiled.errors.ErrorUtils;
+import luan.Lua;
+import luan.LuaState;
+
+
+public class LuaParser extends BaseParser<Object> {
+
+	public Rule Target() {
+		return Sequence(ConstExpr(), EOI);
+	}
+
+	public Rule ConstExpr() {
+		return Sequence(
+			Const(),
+			push(new ConstExpr(pop()))
+		);
+	}
+
+	public Rule Const() {
+		return FirstOf(
+			NilConst(),
+			BinaryConst(),
+			NumberConst()
+		);
+	}
+
+	public Rule NilConst() {
+		return Sequence(
+			String("nil"),
+			push(null)
+		);
+	}
+
+	public Rule BinaryConst() {
+		return FirstOf(
+			TrueConst(),
+			FalseConst()
+		);
+	}
+
+	public Rule TrueConst() {
+		return Sequence(
+			String("true"),
+			push(true)
+		);
+	}
+
+	public Rule FalseConst() {
+		return Sequence(
+			String("false"),
+			push(false)
+		);
+	}
+
+	public Rule NumberConst() {
+		return Sequence(
+			Number(),
+			push(Double.parseDouble(match()))
+		);
+	}
+
+	public Rule Number() {
+		return FirstOf(
+			Sequence(
+				Int(),
+				Optional(
+					Ch('.'),
+					Optional(Int())
+				),
+				NumberExp()
+			),
+			Sequence(
+				Ch('.'),
+				Int(),
+				NumberExp()
+			)
+		);
+	}
+
+	public Rule NumberExp() {
+		return Optional(
+			IgnoreCase('e'),
+			Optional(AnyOf("+-")),
+			Int()
+		);
+	}
+
+    Rule Int() {
+        return OneOrMore(Digit());
+    }
+
+    Rule Digit() {
+        return CharRange('0', '9');
+    }
+
+	// for testing
+	public static void main(String[] args) throws Exception {
+		LuaParser parser = Parboiled.createParser(LuaParser.class);
+		while( true ) {
+            String input = new Scanner(System.in).nextLine();
+			ParsingResult<?> result = new ReportingParseRunner(parser.Target()).run(input);
+			if( result.hasErrors() ) {
+				System.out.println("Parse Errors:\n" + ErrorUtils.printParseErrors(result));
+			} else {
+				Expr expr = (Expr)result.resultValue;
+				LuaState lua = new LuaState();
+				Object val = expr.eval(lua);
+				System.out.println("Result: "+Lua.toString(val));
+			}
+		}
+	}
+}