develop syntax spec

README.md

@@ -22,13 +22,15 @@
 
 ## Syntax Spec
 
-```
+```spec
 program     := defn*
 
 defn        := VAL type ID ;
              | VAL type ID expr ;
 
-type        := ID | [] | [type] | [ type* ARROW type? ]
+type        := ID | type STAR
+             | LBRACK RBRACK | LBRACK type RBRACK
+             | LBRACK type* ARROW type? RBRACK
 
 expr        := atom atom*
 
@@ -37,13 +39,19 @@ atom        := ID
              | STR
              | lambda
              | compound
-             | reference
-             | dereference
+             | STAR
+             | ANDREF
 
 stmt        := defn
              | expr ;        // expr statement
              | return expr ; // return statement
-             | $ ID expr ;   // assignment statement
+             | DOLLAR ID expr ;   // assignment statement
              | if expr compound ;               // if statement
              | if expr compound else compound ; // if-else statement
-```
+
+param_list  := LPAREN (type ID)* RPAREN
+
+lambda      := param_list compound
+
+compound    := LCURLY (stmt)* expr? RCURLY
+```