This is a text format of the NS Grammar.
Sort of BNF-like.

Goal ==> [ Constit [ ; Constit ]* [;]]

Constit ==> Expression
	    GlobDeclaration

Expression ==> SimpleExp
	       CompExp
	       Literal
	       Constructor
	       LValue
	       Assignment
	       ExistsExp
	       FuncCall
	       MsgSend
	       IfExp
	       Iteration
	       BreakExp
	       TryExp
	       LocalDeclaration
	       ConstDeclaration
	       RetExp

SimpleExp ==> Expression BinOp Expression
	      UnOp Expression
	      LPAREN_TOK Expression RPAREN_TOK
	      SELF_TOK

BinOp ==> ArithOp
	  RelOp
	  BoolOp
	  StringOp

ArithOp ==> PLUS_TOK
	    MINUS_TOK
	    STAR_TOK
	    SLASH_TOK
	    DIV_TOK
	    MOD_TOK
	    LSHIFT_TOK
	    RSHIFT_TOK

RelOp ==> EQUALS_TOK
	  NEQUALS_TOK
	  LT_TOK
	  GT_TOK
	  LE_TOK
	  GE_TOK

BoolOp ==> AND_TOK
	   OR_TOK

StringOP ==> CONCAT_TOK
	     CONCAT2_TOK

UnOp ==> MINUS_TOK
	 NOT_TOK

CompExp ==> BEGIN_TOK ExpSeq END_TOK

ExpSeq ==> [ Expression [ SEMI_TOK Expression ] [SEMI_TOK]]

Literal ==> SimpleLiteral
	    PRIME_TOK Object

SimpleLiteral ==> String
		  Integer
		  Real
		  Character
		  TRUE_TOK
		  NIL_TOK

Object ==> SimpleLiteral
	   PathExp
	   Frame
	   Array

PathExp ==> Symbol [POINT_TOK Symbol] PLUS_TOK

Array ==> LBRACK_TOK [ Symbol COLON_TOK ] [ Object [ COMMA_TOK Object ] [ COMMA_TOK ] ] RBRACK_TOK

Frame ==> LCURLY_TOK [ FrameSlot [ COMMA_TOK FrameSlot ] [ COMMA_TOK ] ] RCURLY_TOK

FrameSlot ==> Symbol COLON_TOK Object