X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/ba6e6b64033b1f9de49feccb5c9cd438354481f7..0f00dc4c8eb47e67bc0f148c2dd109f73a451e0a:/math/field-parse.c

diff --git a/math/field-parse.c b/math/field-parse.c
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+/* -*-c-*-
+ *
+ * Parse field descriptions
+ *
+ * (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 "field.h"
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @field_parse@ --- *
+ *
+ * Arguments:	@qd_parse *qd@ = parser context
+ *
+ * Returns:	Field pointer if OK, or null.
+ *
+ * Use:		Parses a field description, which has the form
+ *
+ *		  * `prime', `niceprime' or `binpoly'
+ *		  * an optional `:'
+ *		  * the field modulus
+ */
+
+field *field_parse(qd_parse *qd)
+{
+  field *f = 0;
+  mp *m = MP_NEW, *b = MP_NEW;
+
+  switch (qd_enum(qd, "prime,niceprime,binpoly,binnorm")) {
+    case 0:
+      qd_delim(qd, ':');
+      if ((m = qd_getmp(qd)) == 0) goto done;
+      f = field_prime(m);
+      break;
+    case 1:
+      qd_delim(qd, ':');
+      if ((m = qd_getmp(qd)) == 0) goto done;
+      f = field_niceprime(m);
+      break;
+    case 2:
+      qd_delim(qd, ':');
+      if ((m = qd_getmp(qd)) == 0) goto done;
+      f = field_binpoly(m);
+      break;
+    case 3:
+      qd_delim(qd, ':');
+      if ((m = qd_getmp(qd)) == 0) goto done;
+      qd_delim(qd, ',');
+      if ((b = qd_getmp(qd)) == 0) goto done;
+      f = field_binnorm(m, b);
+      break;
+    default:
+      goto done;
+  }
+  if (!f) qd->e = "bad field parameters";
+done:
+  mp_drop(m);
+  mp_drop(b);
+  return (f);
+}
+
+/*----- That's all, folks -------------------------------------------------*/