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

   1 (* WholeIO.mod implement the ISO WholeIO specification.
   2
   3 Copyright (C) 2008-2023 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 WholeIO ;
  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 IntegerToString, CardinalToString ;
  33 FROM WholeConv IMPORT ScanInt, ScanCard ;
  34 FROM StringChan IMPORT writeString ;
  35 FROM IOConsts IMPORT ReadResults ;
  36
  37
  38 (* Input and output of whole numbers in decimal text form
  39      over specified channels.  The read result is of the
  40      type IOConsts.ReadResults.
  41 *)
  42
  43 IMPORT IOChan;
  44
  45 (* The text form of a signed whole number is
  46      ["+" | "-"], decimal digit, {decimal digit}
  47
  48    The text form of an unsigned whole number is
  49      decimal digit, {decimal digit}
  50 *)
  51
  52 PROCEDURE ReadInt (cid: IOChan.ChanId; VAR int: INTEGER) ;
  53   (* Skips leading spaces, and removes any remaining characters
  54      from cid that form part of a signed whole number.  The
  55      value of this number is assigned to int.  The read result
  56      is set to the value allRight, outOfRange, wrongFormat,
  57      endOfLine, or endOfInput.
  58   *)
  59 VAR
  60    chClass  : ScanClass ;
  61    nextState: ScanState ;
  62    c        : CARDINAL ;
  63    ch       : CHAR ;
  64    negative : BOOLEAN ;
  65 BEGIN
  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+(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(CARDINAL, MAX(INTEGER))+1
  94          THEN
  95             int := MIN(INTEGER)
  96          ELSIF c<=VAL(CARDINAL, MAX(INTEGER))
  97          THEN
  98             int := -VAL(INTEGER, 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: INTEGER;
 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 := IntegerToString(int, width, ' ', TRUE, 10, FALSE) ;
 118    writeString(cid, s) ;
 119    s := KillString(s)
 120 END WriteInt ;
 121
 122
 123 PROCEDURE ReadCard (cid: IOChan.ChanId; VAR card: CARDINAL) ;
 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        : CARDINAL ;
 135 BEGIN
 136    ReadChar(cid, ch) ;
 137    c := 0 ;
 138    nextState := ScanCard ;
 139    REPEAT
 140       nextState(ch, chClass, nextState) ;
 141       IF chClass=valid
 142       THEN
 143          IF ch='+'
 144          THEN
 145             (* ignore *)
 146          ELSE
 147             c := c*10+(ORD(ch)-ORD('0'))
 148          END ;
 149          ReadChar(cid, ch)
 150       ELSIF chClass=padding
 151       THEN
 152          ReadChar(cid, ch)
 153       END
 154    UNTIL (chClass=invalid) OR (chClass=terminator) ;
 155    IF chClass=terminator
 156    THEN
 157       card := c
 158    END
 159 END ReadCard ;
 160
 161
 162 PROCEDURE WriteCard (cid: IOChan.ChanId; card: CARDINAL;
 163                      width: CARDINAL);
 164   (* Writes the value of card to cid in text form, in a field
 165      of the given minimum width. *)
 166 VAR
 167    s: String ;
 168 BEGIN
 169    s := CardinalToString(card, width, ' ', 10, FALSE) ;
 170    writeString(cid, s) ;
 171    s := KillString(s)
 172 END WriteCard ;
 173
 174
 175 END WholeIO.