fix some specs and add for parse

.gitignore

@@ -0,0 +1 @@
+.vscode

README.md

@@ -26,10 +26,13 @@
 
 ```
 program     := defn*
+
 defn        := VAL type ID ;
              | VAL type ID expr ;
 
-expr        := atom atom* ;
+type        := ID | [] | [type] | [ type* ARROW type? ]
+
+expr        := atom atom*
 
 atom        := ID
              | NUM
@@ -40,10 +43,9 @@ atom        := ID
              | dereference
 
 stmt        := defn
-             | expr 
+             | expr ;        // expr statement
-             
+             | return expr ; // return statement
-
+             | $ ID expr ;   // assignment statement
-stmt        := defn | st
+             | if expr compound ;               // if statement
-
+             | if expr compound else compound ; // if-else statement
-
 ```

src/parse.c

@@ -0,0 +1,4 @@
+#include "parse.h"
+
+#include <stdlib.h>
+