mylang.grm

open DataTypes;
open String;
open Char;

%%

%eop EOF
%noshift EOF

(* %pos declares the type of positions for terminals.
   Each symbol has an associated 1left and 1right position. 
 *)
%pos int

%term ID of string  
    | STRLIT of string
    | LBRACE
    | RBRACE
    | LPAREN
    | RPAREN
    | RW_PRINT
    | RW_CLASS
    | RW_VOID
    | EOF
    | SEMI 
    | COMMA 

%start PROGRAM 
%nonterm PROGRAM of mylang_program
      |  MEMBERDECLS of mylang_member_decls 
      |  METHODDECLS of mylang_decl list
      |  METHODDECL of mylang_decl
      |  STMTS  of stmt list
      |  STMT of stmt
      |  OPTIONALSEMI of stmt
      |  ARG of expr 
      |  WRITELIST of stmt list
      |  EXPR of expr

%name MyLang 

%keyword RW_CLASS RW_PRINT

%verbose
%%

    PROGRAM : RW_CLASS ID LBRACE MEMBERDECLS RBRACE  
                      (Program(id(ID), MEMBERDECLS))

    MEMBERDECLS :  METHODDECLS           
                       (MemberDecls(METHODDECLS))
   
    METHODDECLS : METHODDECL METHODDECLS 
                     (METHODDECL::METHODDECLS)
                | (*λ*) 
                     (nil)

    METHODDECL : RW_VOID ID LPAREN RPAREN LBRACE  
                  STMTS
                 RBRACE OPTIONALSEMI (
                        Method(id(ID), STMTS, RW_VOID1left, RBRACE1right)
                 )
   
    OPTIONALSEMI : SEMI 
                     (NoneStmt)
                 | (*λ*) 
                     (NoneStmt)

   STMTS : STMT STMTS 
            (STMT::STMTS)
         | STMT
            ([STMT])

   STMT : RW_PRINT LPAREN STRLIT RPAREN SEMI
           (Write(StrLit(STRLIT, STRLIT1left, STRLIT1right), 
                  RW_PRINT1left, SEMI1right))