DEFINITION MODULE Scanner;		(* gf  05.01.89 (pl0) *)


(* EXPORT QUALIFIED SYMBOL, IDENT, STRING, POSITION,
		 dummyPosition,
		 sym, id, num, pos, strp,
		 GetSymbol,
		 printCode, traceParser, printListing, optimize,
		 InitScanner;
*)


TYPE SYMBOL =	(sNull, sPeriod,
		 sRBracket, sLBracket,
		 sTimes, sDiv,
		 sPlus, sMinus,
		 sEQ, sNE, sLT, sLE, sGT, sGE,
		 sAnd, sOr,
		 sComma, sRParen, sThen, sDo, sBecomes,
		 (* start formula --------------------------------*)
		 sLParen, sOdd, sNot, sNumber, sString,
		 (* start Statement ------------------------------*)
		 sIdent, sCall, sIf, sWhile, sRead, sWrite,
		 (* end   Statement ------------------------------*)
		 sEnd, sElsif, sElse, sSemicolon,
		 (* sArray, sOf, *) sColon,
		 (* start declarations or statementpart ----------*)
		 sBegin, sType, sConst, sVar, sProcedure,
		 sEof);

TYPE IDENT  = INTEGER;

TYPE STRING = POINTER TO ARRAY[0..99] OF CHAR;

TYPE POSITION = RECORD		(* position in source text *)
		  line, column : CARDINAL
		END;


VAR sym : SYMBOL;	(* last symbol read			*)
    id	: IDENT;	(* identifier number			*)
    num : CARDINAL;	(* last number read			*)
    strp: STRING;	(* pointer to string read		*)
    pos : POSITION;	(* current position in source text	*)

    dummyPosition    : POSITION;



VAR printCode,
    traceParser,
    optimize,
    printListing  : BOOLEAN;

    noPosition	  : POSITION;






PROCEDURE GetSymbol;	(* get next symbol;
			 * results: sym, id, num, strp, pos
			 *)

PROCEDURE InitScanner;

END Scanner.