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

   1 (* CharClass.mod implement the ISO CharClass specification.
   2
   3 Copyright (C) 2002-2024 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 CharClass ;
  28
  29 FROM ASCII IMPORT lf, cr, tab ;
  30
  31 (* Classification of values of the type CHAR *)
  32
  33 (* Returns TRUE if and only if ch is classified as a numeric character *)
  34
  35 PROCEDURE IsNumeric (ch: CHAR) : BOOLEAN ;
  36 BEGIN
  37    RETURN (ch>='0') AND (ch<='9')
  38 END IsNumeric ;
  39
  40
  41 (* Returns TRUE if and only if ch is classified as a letter *)
  42
  43 PROCEDURE IsLetter (ch: CHAR): BOOLEAN;
  44 BEGIN
  45    RETURN ((ch>='a') AND (ch<='z')) OR ((ch>='A') AND (ch<='Z'))
  46 END IsLetter ;
  47
  48
  49 (* Returns TRUE if and only if ch is classified as an upper case letter *)
  50
  51 PROCEDURE IsUpper (ch: CHAR): BOOLEAN;
  52 BEGIN
  53    RETURN (ch>='A') AND (ch<='Z')
  54 END IsUpper ;
  55
  56
  57 (* Returns TRUE if and only if ch is classified as a lower case letter *)
  58
  59 PROCEDURE IsLower (ch: CHAR): BOOLEAN;
  60 BEGIN
  61    RETURN (ch>='a') AND (ch<='z')
  62 END IsLower ;
  63
  64
  65 (* Returns TRUE if and only if ch represents a control function *)
  66
  67 PROCEDURE IsControl (ch: CHAR): BOOLEAN;
  68 BEGIN
  69    RETURN (ch<' ')
  70 END IsControl ;
  71
  72
  73 (* Returns TRUE if and only if ch represents a space character or a format effector *)
  74
  75 PROCEDURE IsWhiteSpace (ch: CHAR): BOOLEAN;
  76 BEGIN
  77    RETURN (ch=' ') OR (ch=cr) OR (ch=lf) OR (ch=tab)
  78 END IsWhiteSpace ;
  79
  80
  81 END CharClass.