.. _gm2-libs-iso-shortio:

gm2-libs-iso/ShortIO
^^^^^^^^^^^^^^^^^^^^

.. code-block:: modula2

  DEFINITION MODULE ShortIO;

    (* Input and output of short real numbers in decimal text form
       over specified channels.  The read result is of the type
       IOConsts.ReadResults.
    *)

  IMPORT IOChan;

    (* The text form of a signed fixed-point real number is
         ["+" | "-"], decimal digit, {decimal digit}, [".",
         {decimal digit}]

       The text form of a signed floating-point real number is
         signed fixed-point real number,
         "E", ["+" | "-"], decimal digit, {decimal digit}
    *)

  ReadReal
  PROCEDURE ReadReal (cid: IOChan.ChanId; VAR real: SHORTREAL);
    (* Skips leading spaces, and removes any remaining characters
       from cid that form part of a signed fixed or floating
       point number.  The value of this number is assigned to real.
       The read result is set to the value allRight, outOfRange,
       wrongFormat, endOfLine, or endOfInput.
    *)

  WriteFloat
  PROCEDURE WriteFloat (cid: IOChan.ChanId; real: SHORTREAL;
                        sigFigs: CARDINAL; width: CARDINAL);
    (* Writes the value of real to cid in floating-point text form,
       with sigFigs significant figures, in a field of the given
       minimum width.
    *)

  WriteEng
  PROCEDURE WriteEng (cid: IOChan.ChanId; real: SHORTREAL;
                      sigFigs: CARDINAL; width: CARDINAL);
    (* As for WriteFloat, except that the number is scaled with
       one to three digits in the whole number part, and with an
       exponent that is a multiple of three.
    *)

  WriteFixed
  PROCEDURE WriteFixed (cid: IOChan.ChanId; real: SHORTREAL;
                        place: INTEGER; width: CARDINAL);
    (* Writes the value of real to cid in fixed-point text form,
       rounded to the given place relative to the decimal point,
       in a field of the given minimum width.
    *)

  WriteReal
  PROCEDURE WriteReal (cid: IOChan.ChanId; real: SHORTREAL;
                       width: CARDINAL);
    (* Writes the value of real to cid, as WriteFixed if the
       sign and magnitude can be shown in the given width, or
       otherwise as WriteFloat.  The number of places or
       significant digits depends on the given width.
    *)

  END ShortIO.