(*
 * This is a version of ../inputs//term-factor-does-work.rsl with the even
 * latester and greatester grammar-like syntax.
 *)

module TermFactorAttributeGrammar;

    (*
     * Attribute definitions.
     *)
    define obj attribute type:Type;
    define obj attribute valu:Value;
    define obj attribute text:string;
    define obj attribute type_:Type;

    (*
     * Attribute type definitions.
     *)
    obj Type = string;
    obj Value = number;
    obj Symtab = SymtabEntry*;
    obj SymtabEntry = n:Name and t:Type and v:Value;
    obj Name = string;

    (*
     * Auxiliary functions.
     *)
    function Lookup(s:Symtab, n:Name)->SymtabEntry;

    (*
     * Global attributes.
     *)
    var symtab:Symtab;

    (*
     * Grammar and semantic action definitions.
     *)

    rule E =	e:E "+" t:T
		    {this.:type = (if e.:type = t.:type
                                    then e.:type else "ERROR");
		     this.:valu = e.:valu + t.:valu;}
						-- ^ note extra ';', which is OK
        |
		t:T
		    {this.:type = t.:type;
                     this.:valu = t.:valu}
	;

    rule T =	t:T "*" f:F
		    {this.:type = (if e.:type = t.:type
                                    then e.:type else "ERROR");
		     this.:valu = e.:valu * t.:valu}
	|
		f:F
		    {this.:type = f.:type;
                     this.:valu = f.:valu}
	;

    rule F =	x:"x"
	            {this.:type = Lookup(symtab, x.:text).t;
                     this.:valu = Lookup(symtab, x.:text).v}
	;


rule literal =
	sl:STRING_LITERAL
		  {
			this.:type_ = Lookup(symtab, x.:text);
	            this.:type = Lookup(symtab, x.:text).t;
                     this.:valu = Lookup(symtab, x.:text).v}
		;

obj STRING_LITERAL;

end TermFactorAttributeGrammar;