/*
 * Copyright (c) 2002, The Tendra Project <http://www.ten15.org/>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
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 *    notice unmodified, this list of conditions, and the following
 *    disclaimer.
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 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *
 *    		 Crown Copyright (c) 1997
 *
 *    This TenDRA(r) Computer Program is subject to Copyright
 *    owned by the United Kingdom Secretary of State for Defence
 *    acting through the Defence Evaluation and Research Agency
 *    (DERA).  It is made available to Recipients with a
 *    royalty-free licence for its use, reproduction, transfer
 *    to other parties and amendment for any purpose not excluding
 *    product development provided that any such use et cetera
 *    shall be deemed to be acceptance of the following conditions:-
 *
 *        (1) Its Recipients shall ensure that this Notice is
 *        reproduced upon any copies or amended versions of it;
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 *        for the relevant amendment or amendments;
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 *        (3) Its onward transfer from a recipient to another
 *        party shall be deemed to be that party's acceptance of
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 *        (4) DERA gives no warranty or assurance as to its
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 * $TenDRA: tendra/src/tools/tld/syntax.h,v 1.8 2005/09/26 20:20:16 stefanf Exp $
 */


/**** syntax.h --- Character classification.
 *
 ** Author: Steve Folkes <smf@hermes.mod.uk>
 *
 **** Commentary:
 *
 ***=== INTRODUCTION =========================================================
 *
 * This file specifies the interface to a number of syntax table manipulation
 * functions.  I ought to be able to use <ctype.h> for this, but I can't
 * because it doesn't have routines to get the numeric value for alphabetic
 * characters (amongst other omissions).  As I need to do this here, I might
 * as well put in support for everything.
 *
 * It is assumed elsewhere (in association with the input stream facility
 * specified in the file "istream.h") that the null and newline characters are
 * white space, and have no digit value.
 *
 ***=== CONSTANTS ============================================================
 *
 ** Constant:	SYNTAX_NO_VALUE
 *
 * This value is returned by the ``syntax_value'' function for characters that
 * do not have a digit value.
 *
 ***=== FUNCTIONS ============================================================
 *
 ** Function:	int		syntax_value(char c)
 ** Exceptions:
 *
 * This function returns the positive integer digit value that the specified
 * character should have, or ``SYNTAX_NO_VALUE'' if it has no value.
 *
 ** Function:	char		syntax_upcase(char c)
 ** Exceptions:
 *
 * This function returns the upper case version of the specified character if
 * it has one, otherwise it just returns the character.
 *
 ** Function:	char		syntax_downcase(char c)
 ** Exceptions:
 *
 * This function returns the lower case version of the specified character if
 * it has one, otherwise it just returns the character.
 *
 ** Function:	BoolT		syntax_is_white_space(char c)
 *
 * This function returns true if the specified character is a white space
 * character, and false otherwise.
 *
 ** Function:	BoolT		syntax_is_printable(char c)
 ** Exceptions:
 *
 * This function returns true if the specified character can be printed, and
 * false otherwise.
 *
 ** Function:	BoolT		syntax_is_letter(char c)
 ** Exceptions:
 *
 * This function returns true if the specified character is a letter, and
 * false otherwise.
 *
 ** Function:	BoolT		syntax_is_digit(char c)
 ** Exceptions:
 *
 * This function returns true if the specified character is a decimal digit,
 * and false otherwise.
 *
 **** Change Log:*/

/****************************************************************************/

#ifndef H_SYNTAX
#define H_SYNTAX

#include "config.h"

/*--------------------------------------------------------------------------*/

#define SYNTAX_NO_VALUE (-1)

/*--------------------------------------------------------------------------*/

extern int			syntax_value(char);
extern char			syntax_upcase(char);
extern char			syntax_downcase(char);
extern BoolT			syntax_is_white_space(char);
extern BoolT			syntax_is_printable(char);
extern BoolT			syntax_is_letter(char);
extern BoolT			syntax_is_digit(char);

#endif /* !defined (H_SYNTAX) */