git.distorted.org.uk Git - u/mdw/catacomb/blob - qdparse.c

   1 /* -*-c-*-
   2  *
   3  * $Id: qdparse.c,v 1.2 2004/04/08 01:36:15 mdw Exp $
   4  *
   5  * Quick-and-dirty parser
   6  *
   7  * (c) 2004 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Catacomb.
  13  *
  14  * Catacomb is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU Library General Public License as
  16  * published by the Free Software Foundation; either version 2 of the
  17  * License, or (at your option) any later version.
  18  *
  19  * Catacomb is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU Library General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU Library General Public
  25  * License along with Catacomb; if not, write to the Free
  26  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  27  * MA 02111-1307, USA.
  28  */
  29
  30 /*----- Header files ------------------------------------------------------*/
  31
  32 #include <ctype.h>
  33 #include <string.h>
  34
  35 #include "qdparse.h"
  36
  37 /*----- Main code ---------------------------------------------------------*/
  38
  39 /* --- @qd_skipspc@ --- *
  40  *
  41  * Arguments:   @qd_parse *qd@ = context
  42  *
  43  * Returns:     ---
  44  *
  45  * Use:         Skips spaces in the string.  No errors.
  46  */
  47
  48 void qd_skipspc(qd_parse *qd)
  49 {
  50   while (isspace((unsigned char)*qd->p))
  51     qd->p++;
  52 }
  53
  54 /* --- @qd_delim@ --- *
  55  *
  56  * Arguments:   @qd_parse *qd@ = context
  57  *              @int ch@ = character to compare with
  58  *
  59  * Returns:     Nonzero if it was, zero if it wasn't.
  60  *
  61  * Use:         Checks the next (non-whitespace) character is what we
  62  *              expect.  If it is, the character is eaten; otherwise it's no
  63  *              big deal.
  64  */
  65
  66 int qd_delim(qd_parse *qd, int ch)
  67 {
  68   qd_skipspc(qd);
  69   if (*qd->p != ch)
  70     return (0);
  71   qd->p++;
  72   return (1);
  73 }
  74
  75 /* --- @qd_enum@ --- *
  76  *
  77  * Arguments:   @qd_parse *qd@ = context
  78  *              @const char *e@ = list of enum strings, space separated
  79  *
  80  * Returns:     Index of the string matched, or @-1@.
  81  *
  82  * Use:         Matches a keyword.
  83  */
  84
  85 int qd_enum(qd_parse *qd, const char *e)
  86 {
  87   size_t n;
  88   int i = 0;
  89
  90   qd_skipspc(qd);
  91   for (;;) {
  92     e += strspn(e, ", ");
  93     if (!*e) break;
  94     n = strcspn(e, ", ");
  95     if (strncmp(qd->p, e, n) == 0 && !isalnum((unsigned char)qd->p[n])) {
  96       qd->p += n;
  97       return (i);
  98     }
  99     i++; e += n;
 100   }
 101   qd->e = "unrecognized keyword";
 102   return (-1);
 103 }
 104
 105 /* --- @qd_getmp@ --- *
 106  *
 107  * Arguments:   @qd_parse *qd@ = context
 108  *
 109  * Returns:     The integer extracted, or null.
 110  *
 111  * Use:         Parses a multiprecision integer from a string.
 112  */
 113
 114 mp *qd_getmp(qd_parse *qd)
 115 {
 116   char *q;
 117   mp *m;
 118
 119   qd_skipspc(qd);
 120   m = mp_readstring(MP_NEW, qd->p, &q, 0);
 121   if (m && !isalnum((unsigned char)*q))
 122     qd->p = q;
 123   else {
 124     mp_drop(m);
 125     qd->e = "bad number";
 126   }
 127   return (m);
 128 }
 129
 130 /* --- @qd_eofp@ --- *
 131  *
 132  * Arguments:   @qd_parse *qd@ = context
 133  *
 134  * Returns:     Nonzero if at EOF, zero otherwise.
 135  */
 136
 137 int qd_eofp(qd_parse *qd)
 138 {
 139   qd_skipspc(qd);
 140   return (!*qd->p);
 141 }
 142
 143 /*----- That's all, folks -------------------------------------------------*/