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

   1 /* -*-c-*-
   2  *
   3  * $Id: field-parse.c,v 1.4 2004/04/08 01:36:15 mdw Exp $
   4  *
   5  * Parse field descriptions
   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 "field.h"
  33
  34 /*----- Main code ---------------------------------------------------------*/
  35
  36 /* --- @field_parse@ --- *
  37  *
  38  * Arguments:   @qd_parse *qd@ = parser context
  39  *
  40  * Returns:     Field pointer if OK, or null.
  41  *
  42  * Use:         Parses a field description, which has the form
  43  *
  44  *                * `prime', `niceprime' or `binpoly'
  45  *                * an optional `:'
  46  *                * the field modulus
  47  */
  48
  49 field *field_parse(qd_parse *qd)
  50 {
  51   field *f = 0;
  52   mp *m = MP_NEW, *b = MP_NEW;
  53
  54   switch (qd_enum(qd, "prime,niceprime,binpoly,binnorm")) {
  55     case 0:
  56       qd_delim(qd, ':');
  57       if ((m = qd_getmp(qd)) == 0) goto done;
  58       f = field_prime(m);
  59       break;
  60     case 1:
  61       qd_delim(qd, ':');
  62       if ((m = qd_getmp(qd)) == 0) goto done;
  63       f = field_niceprime(m);
  64       break;
  65     case 2:
  66       qd_delim(qd, ':');
  67       if ((m = qd_getmp(qd)) == 0) goto done;
  68       f = field_binpoly(m);
  69       break;
  70     case 3:
  71       qd_delim(qd, ':');
  72       if ((m = qd_getmp(qd)) == 0) goto done;
  73       qd_delim(qd, ',');
  74       if ((b = qd_getmp(qd)) == 0) goto done;
  75       f = field_binnorm(m, b);
  76       break;
  77     default:
  78       goto done;
  79   }
  80   if (!f) qd->e = "bad field parameters";
  81 done:
  82   mp_drop(m);
  83   mp_drop(b);
  84   return (f);
  85 }
  86
  87 /*----- That's all, folks -------------------------------------------------*/