IMPLEMENTATION MODULE SRealIO;
IMPORT IOConsts, SIOResult;
FROM IOConsts IMPORT allRight;

PROCEDURE m2realconv (x : REAL; mode : INTEGER; prec : INTEGER;
                      VAR s : ARRAY OF CHAR) : INTEGER;
  EXTERNAL;
PROCEDURE m2readreal () : REAL;
  EXTERNAL;
PROCEDURE m2writechar (c : CHAR);
  EXTERNAL;
PROCEDURE m2write (VAR s : ARRAY OF CHAR);
  EXTERNAL;

PROCEDURE StrLen (VAR s : ARRAY OF CHAR) : CARDINAL;
  VAR i : CARDINAL;
BEGIN
  i := 0;
  WHILE (i <= HIGH(s)) AND (s[i] # CHR(0)) DO INC(i) END;
  RETURN i
END StrLen;

PROCEDURE WritePadded (VAR s : ARRAY OF CHAR; width : CARDINAL);
  VAR n, i : CARDINAL;
BEGIN
  n := StrLen(s);
  IF width > n THEN
    i := width - n;
    WHILE i > 0 DO m2writechar(" "); DEC(i) END
  END;
  m2write(s)
END WritePadded;

PROCEDURE WriteFloat (real : REAL; sigFigs : CARDINAL; width : CARDINAL);
  VAR s : ARRAY [0 .. 127] OF CHAR;
    n : INTEGER;
BEGIN
  n := m2realconv(real, 1, VAL(INTEGER, sigFigs), s);
  WritePadded(s, width)
END WriteFloat;

PROCEDURE WriteEng (real : REAL; sigFigs : CARDINAL; width : CARDINAL);
  VAR s : ARRAY [0 .. 127] OF CHAR;
    n : INTEGER;
BEGIN
  n := m2realconv(real, 2, VAL(INTEGER, sigFigs), s);
  WritePadded(s, width)
END WriteEng;

PROCEDURE WriteFixed (real : REAL; place : INTEGER; width : CARDINAL);
  VAR s : ARRAY [0 .. 127] OF CHAR;
    n : INTEGER;
BEGIN
  n := m2realconv(real, 0, place, s);
  WritePadded(s, width)
END WriteFixed;

PROCEDURE WriteReal (real : REAL; width : CARDINAL);
BEGIN
  (* ISO: fixed if it fits, otherwise floating; approximate by
     fixed with a width-derived number of places. *)
  IF width <= 16 THEN
    WriteFixed(real, 6, width)
  ELSE
    WriteFloat(real, 6, width)
  END
END WriteReal;

PROCEDURE ReadReal (VAR real : REAL);
BEGIN
  real := m2readreal();
  SIOResult.SetReadResult(allRight)
END ReadReal;

END SRealIO.