From 4a9b22952a4ed3901108eaca5d5027b5509473c1 Mon Sep 17 00:00:00 2001
From: Valk Richard Li <48872266+ValKmjolnir@users.noreply.github.com>
Date: Mon, 14 Sep 2020 13:52:25 +0800
Subject: [PATCH] Update README.md

---
 README.md | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index ffb4c05..dd5fe89 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,19 @@ There is a Nasal console in FlightGear but sometimes it is not so easy for every
 
 So this is an interpreter for Nasal written by C++.
 
-The interpreter is still in development.Anyone who interested in this could also join us!
+The interpreter is still in development.We really need your support!
+
+# Why writing Nasal Interpreter
+
+Nasal is a script language first used in Flightgear.
+
+But in last summer holiday, members in FGPRC told me that it is hard to debug with nasal-console in Flightgear, especially when checking syntax error.
+
+So i tried to write a new interpreter to help them checking syntax error and even, runtime error.
+
+I wrote the lexer, parser and runtime(nasal virtual machine/ast-runtime virtual machine) to help checking errors.
+
+They found it easier for them to check errors before copying nasal-codes in nasal-console in Flightgear to test.
   
 # Lexical Analysis