New multiprecision integer arithmetic suite.

[u/mdw/catacomb] / mptext-string.c

diff --git a/mptext-string.c b/mptext-string.c
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+++ b/mptext-string.c
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+/* -*-c-*-
+ *
+ * $Id: mptext-string.c,v 1.1 1999/11/17 18:02:16 mdw Exp $
+ *
+ * Reading and writing large integers on strings
+ *
+ * (c) 1999 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.
+ */
+
+/*----- Revision history --------------------------------------------------* 
+ *
+ * $Log: mptext-string.c,v $
+ * Revision 1.1  1999/11/17 18:02:16  mdw
+ * New multiprecision integer arithmetic suite.
+ *
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <string.h>
+
+#include "mptext.h"
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- Operations table --- */
+
+static int get(void *p)
+{
+  mptext_stringctx *c = p;
+  if (c->buf >= c->lim)
+    return (EOF);
+  return (*c->buf++);
+}
+
+static void unget(int ch, void *p)
+{
+  mptext_stringctx *c = p;
+  if (ch != EOF)
+    c->buf--;
+}
+
+static int put(char *s, size_t sz, void *p)
+{
+  mptext_stringctx *c = p;
+  int rc = 0;
+  if (sz > c->lim - c->buf) {
+    sz = c->lim - c->buf;
+    rc = EOF;
+  }
+  if (sz) {
+    memcpy(c->buf, s, sz);
+    c->buf += sz;
+  }
+  return (rc);
+}
+
+const mptext_ops mptext_stringops = { get, unget, put };
+
+/* --- Convenience functions --- */
+
+mp *mp_readstring(mp *m, const char *p, char **end, int radix)
+{
+  mptext_stringctx c;
+  c.buf = (char *)p;
+  c.lim = c.buf + strlen(p);
+  m = mp_read(m, radix, &mptext_stringops, &c);
+  if (end)
+    *end = c.buf;
+  return (m);
+}
+
+int mp_writestring(mp *m, char *p, size_t sz, int radix)
+{
+  mptext_stringctx c;
+  int rc;
+  if (!sz)
+    return (0);
+  c.buf = p;
+  c.lim = p + sz - 1;
+  rc = mp_write(m, radix, &mptext_stringops, &c);
+  *c.buf = 0;
+  return (rc);
+}
+
+/*----- That's all, folks -------------------------------------------------*/