update

version2.0/lib/io.nas

@@ -1,10 +1,22 @@
 # nasal lib io.nas
-# 2020/2/4
+# 2020/2/6
 # this file is used to avoid name confliction
 # and is used to avoid name undefined
 # before running this file will be translated to abstract syntax tree
 # and this ast will be linked before main ast as main-ast's beginning
 
+var io=
+{
+    open:func(){},
+    close:func(){},
+    read:func(){},
+    write:func(){},
+    seek:func(){},
+    tell:func(){},
+    readln:func(){},
+    stat:func(){},
+};
+
 var input=func(filename="")
 {
     if(filename=="")