gcc/m2/gm2-libs-iso/LongWholeIO.mod

   1 (* LongWholeIO.mod provides a WholeIO interface for gm2 LONGINT/LONGCARD.
   2
   3 Copyright (C) 2008-2024 Free Software Foundation, Inc.
   4 Contributed by Gaius Mulley <gaius.mulley@southwales.ac.uk>.
   5
   6 This file is part of GNU Modula-2.
   7
   8 GNU Modula-2 is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GNU Modula-2 is distributed in the hope that it will be useful, but
  14 WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 General Public License for more details.
  17
  18 Under Section 7 of GPL version 3, you are granted additional
  19 permissions described in the GCC Runtime Library Exception, version
  20 3.1, as published by the Free Software Foundation.
  21
  22 You should have received a copy of the GNU General Public License and
  23 a copy of the GCC Runtime Library Exception along with this program;
  24 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  25 <http://www.gnu.org/licenses/>.  *)
  26
  27 IMPLEMENTATION MODULE LongWholeIO ;
  28
  29 FROM ConvTypes IMPORT ScanClass, ScanState ;
  30 FROM TextIO IMPORT WriteChar, ReadChar ;
  31 FROM DynamicStrings IMPORT String, char, KillString, Length ;
  32 FROM StringConvert IMPORT LongIntegerToString, LongCardinalToString ;
  33 FROM WholeConv IMPORT ScanInt, ScanCard ;
  34 FROM StringChan IMPORT writeString ;
  35 FROM IOConsts IMPORT ReadResults ;
  36 FROM TextUtil IMPORT SkipSpaces ;
  37
  38
  39 (* Input and output of whole numbers in decimal text form
  40      over specified channels.  The read result is of the
  41      type IOConsts.ReadResults.
  42 *)
  43
  44 (* The text form of a signed whole number is
  45      ["+" | "-"], decimal digit, {decimal digit}
  46
  47    The text form of an unsigned whole number is
  48      decimal digit, {decimal digit}
  49 *)
  50
  51 PROCEDURE ReadInt (cid: IOChan.ChanId; VAR int: LONGINT) ;
  52   (* Skips leading spaces, and removes any remaining characters
  53      from cid that form part of a signed whole number.  The
  54      value of this number is assigned to int.  The read result
  55      is set to the value allRight, outOfRange, wrongFormat,
  56      endOfLine, or endOfInput.
  57   *)
  58 VAR
  59    chClass  : ScanClass ;
  60    nextState: ScanState ;
  61    c        : LONGCARD ;
  62    ch       : CHAR ;
  63    negative : BOOLEAN ;
  64 BEGIN
  65    SkipSpaces (cid) ;
  66    ReadChar(cid, ch) ;
  67    negative := FALSE ;
  68    c := 0 ;
  69    nextState := ScanInt ;
  70    REPEAT
  71       nextState(ch, chClass, nextState) ;
  72       IF chClass=valid
  73       THEN
  74          IF ch='+'
  75          THEN
  76             (* ignore *)
  77          ELSIF ch='-'
  78          THEN
  79             negative := NOT negative
  80          ELSE
  81             c := c*10+VAL(LONGCARD, ORD(ch)-ORD('0'))
  82          END ;
  83          ReadChar(cid, ch)
  84       ELSIF chClass=padding
  85       THEN
  86          ReadChar(cid, ch)
  87       END
  88    UNTIL (chClass=invalid) OR (chClass=terminator) ;
  89    IF chClass=terminator
  90    THEN
  91       IF negative
  92       THEN
  93          IF c=VAL(LONGCARD, MAX(LONGINT))+1
  94          THEN
  95             int := MIN(LONGINT)
  96          ELSIF c<=VAL(LONGCARD, MAX(LONGINT))
  97          THEN
  98             int := -VAL(LONGINT, c)
  99          ELSE
 100             (* overflow *)
 101             IOChan.SetReadResult(cid, outOfRange)
 102          END
 103       ELSE
 104          int := c
 105       END
 106    END
 107 END ReadInt ;
 108
 109
 110 PROCEDURE WriteInt (cid: IOChan.ChanId; int: LONGINT;
 111                     width: CARDINAL) ;
 112   (* Writes the value of int to cid in text form, in a field of
 113      the given minimum width. *)
 114 VAR
 115    s: String ;
 116 BEGIN
 117    s := LongIntegerToString (int, width, ' ', int < 0, 10, FALSE) ;
 118    writeString (cid, s) ;
 119    s := KillString (s)
 120 END WriteInt ;
 121
 122
 123 PROCEDURE ReadCard (cid: IOChan.ChanId; VAR card: LONGCARD) ;
 124   (* Skips leading spaces, and removes any remaining characters
 125      from cid that form part of an unsigned whole number.  The
 126      value of this number is assigned to card. The read result
 127      is set to the value allRight, outOfRange, wrongFormat,
 128      endOfLine, or endOfInput.
 129   *)
 130 VAR
 131    chClass  : ScanClass ;
 132    nextState: ScanState ;
 133    ch       : CHAR ;
 134    c        : LONGCARD ;
 135 BEGIN
 136    SkipSpaces (cid) ;
 137    ReadChar(cid, ch) ;
 138    c := 0 ;
 139    nextState := ScanCard ;
 140    REPEAT
 141       nextState(ch, chClass, nextState) ;
 142       IF chClass=valid
 143       THEN
 144          IF ch='+'
 145          THEN
 146             (* ignore *)
 147          ELSE
 148             c := c*10+VAL(LONGCARD, ORD(ch)-ORD('0'))
 149          END ;
 150          ReadChar(cid, ch)
 151       ELSIF chClass=padding
 152       THEN
 153          ReadChar(cid, ch)
 154       END
 155    UNTIL (chClass=invalid) OR (chClass=terminator) ;
 156    IF chClass=terminator
 157    THEN
 158       card := c
 159    END
 160 END ReadCard ;
 161
 162
 163 PROCEDURE WriteCard (cid: IOChan.ChanId; card: LONGCARD;
 164                      width: CARDINAL);
 165   (* Writes the value of card to cid in text form, in a field
 166      of the given minimum width. *)
 167 VAR
 168    s: String ;
 169 BEGIN
 170    s := LongCardinalToString(card, width, ' ', 10, FALSE) ;
 171    writeString(cid, s) ;
 172    s := KillString(s)
 173 END WriteCard ;
 174
 175
 176 END LongWholeIO.