DEFINITION MODULE RealConversions;
(*
  Module:	string-to-real and real-to-string conversions
  Author:	Ceriel J.H. Jacobs
  Version:	$Id$
*)

  PROCEDURE StringToReal(str: ARRAY OF CHAR; VAR r: REAL; VAR ok: BOOLEAN);
  (* Convert string "str" to a real number "r" according to the syntax:
     
	['+'|'-'] digit {digit} ['.' digit {digit}]
	['E' ['+'|'-'] digit {digit}]

     ok := "conversion succeeded"
     Leading blanks are skipped;
     Input terminates with a blank or any control character.
  *)

  PROCEDURE StringToLongReal(str: ARRAY OF CHAR;
			     VAR r: LONGREAL;
			     VAR ok: BOOLEAN);

  PROCEDURE RealToString(r: REAL;
			 width, digits: INTEGER;
			 VAR str: ARRAY OF CHAR;
			 VAR ok: BOOLEAN);
  (* Convert real number "r" to string "str", either in fixed-point or
     exponent notation.
     "digits" is the number digits to the right of the decimal point,
     "width" is the maximum width of the notation.
     If digits < 0, exponent notation is used, otherwise fixed-point.
     If fewer than "width" characters are needed, leading blanks are inserted.
     If the representation does not fit in "width", then ok is set to FALSE.
  *)

  PROCEDURE LongRealToString(r: LONGREAL;
			 width, digits: INTEGER;
			 VAR str: ARRAY OF CHAR;
			 VAR ok: BOOLEAN);

END RealConversions.