| (* Library module defined by the International Standard |
| Information technology - programming languages |
| BS ISO/IEC 10514-1:1996E Part 1: Modula-2, Base Language. |
| |
| Copyright ISO/IEC (International Organization for Standardization |
| and International Electrotechnical Commission) 1996-2021. |
| |
| It may be freely copied for the purpose of implementation (see page |
| 707 of the Information technology - Programming languages Part 1: |
| Modula-2, Base Language. BS ISO/IEC 10514-1:1996). *) |
| |
| DEFINITION MODULE RealIO; |
| |
| (* Input and output of 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} |
| *) |
| |
| PROCEDURE ReadReal (cid: IOChan.ChanId; VAR real: REAL); |
| (* 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. |
| *) |
| |
| PROCEDURE WriteFloat (cid: IOChan.ChanId; real: REAL; |
| 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. |
| *) |
| |
| PROCEDURE WriteEng (cid: IOChan.ChanId; real: REAL; |
| 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. |
| *) |
| |
| PROCEDURE WriteFixed (cid: IOChan.ChanId; real: REAL; |
| 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. |
| *) |
| |
| PROCEDURE WriteReal (cid: IOChan.ChanId; |
| real: REAL; 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 RealIO. |
