.gitignore: Ignore `auto-version' script.

[u/mdw/catacomb] / qdparse.c

/* -*-c-*-
 *
 * $Id: qdparse.c,v 1.2 2004/04/08 01:36:15 mdw Exp $
 *
 * Quick-and-dirty parser
 *
 * (c) 2004 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------*
 *
 * This file is part of Catacomb.
 *
 * Catacomb is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * Catacomb is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with Catacomb; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */

/*----- Header files ------------------------------------------------------*/

#include <ctype.h>
#include <string.h>

#include "qdparse.h"

/*----- Main code ---------------------------------------------------------*/

/* --- @qd_skipspc@ --- *
 *
 * Arguments:	@qd_parse *qd@ = context
 *
 * Returns:	---
 *
 * Use:		Skips spaces in the string.  No errors.
 */

void qd_skipspc(qd_parse *qd)
{
  while (isspace((unsigned char)*qd->p))
    qd->p++;
}

/* --- @qd_delim@ --- *
 *
 * Arguments:	@qd_parse *qd@ = context
 *		@int ch@ = character to compare with
 *
 * Returns:	Nonzero if it was, zero if it wasn't.
 *
 * Use:		Checks the next (non-whitespace) character is what we
 *		expect.  If it is, the character is eaten; otherwise it's no
 *		big deal.
 */

int qd_delim(qd_parse *qd, int ch)
{
  qd_skipspc(qd);
  if (*qd->p != ch)
    return (0);
  qd->p++;
  return (1);
}

/* --- @qd_enum@ --- *
 *
 * Arguments:	@qd_parse *qd@ = context
 *		@const char *e@ = list of enum strings, space separated
 *
 * Returns:	Index of the string matched, or @-1@.
 *
 * Use:		Matches a keyword.
 */

int qd_enum(qd_parse *qd, const char *e)
{
  size_t n;
  int i = 0;

  qd_skipspc(qd);
  for (;;) {
    e += strspn(e, ", ");
    if (!*e) break;
    n = strcspn(e, ", ");
    if (strncmp(qd->p, e, n) == 0 && !isalnum((unsigned char)qd->p[n])) {
      qd->p += n;
      return (i);
    }
    i++; e += n;
  }
  qd->e = "unrecognized keyword";
  return (-1);
}

/* --- @qd_getmp@ --- *
 *
 * Arguments:	@qd_parse *qd@ = context
 *
 * Returns:	The integer extracted, or null.
 *
 * Use:		Parses a multiprecision integer from a string.
 */

mp *qd_getmp(qd_parse *qd)
{
  char *q;
  mp *m;

  qd_skipspc(qd);
  m = mp_readstring(MP_NEW, qd->p, &q, 0);
  if (m && !isalnum((unsigned char)*q))
    qd->p = q;
  else {
    mp_drop(m);
    qd->e = "bad number";
  }
  return (m);
}

/* --- @qd_eofp@ --- *
 *
 * Arguments:	@qd_parse *qd@ = context
 *
 * Returns:	Nonzero if at EOF, zero otherwise.
 */

int qd_eofp(qd_parse *qd)
{
  qd_skipspc(qd);
  return (!*qd->p);
}

/*----- That's all, folks -------------------------------------------------*/