/* -*-c-*-
*
- * $Id: mpscan.c,v 1.1 1999/09/03 08:41:12 mdw Exp $
+ * $Id: mpscan.c,v 1.4 2004/04/08 01:36:15 mdw Exp $
*
* Sequential bit scan of multiprecision integers
*
* (c) 1999 Straylight/Edgeware
*/
-/*----- Licensing notice --------------------------------------------------*
+/*----- Licensing notice --------------------------------------------------*
*
* This file is part of Catacomb.
*
* 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: mpscan.c,v $
- * Revision 1.1 1999/09/03 08:41:12 mdw
- * Initial import.
- *
- */
-
/*----- Header files ------------------------------------------------------*/
-/*----- Data structures ---------------------------------------------------*/
-
-/*----- Static variables --------------------------------------------------*/
+#include "mpscan.h"
-/*----- Main code ---------------------------------------------------------*/
+/*----- Right-to-left scanning --------------------------------------------*/
/* --- @mpscan_initx@ --- *
*
* Arguments: @mpscan *m@ = pointer to bitscanner structure
- * @const mpw *v@ = vector of words to scan
- * @size_t len@ = length of vector in words
+ * @const mpw *v, *vl@ = vector of words to scan
*
* Returns: ---
*
* out.
*/
-void mpscan_initx(mpscan *m, const mpw *v, size_t len)
+void mpscan_initx(mpscan *m, const mpw *v, const mpw *vl)
{
- MPSCAN_INITX(m, v, len);
+ MPSCAN_INITX(m, v, vl);
}
/* --- @mpscan_step@ --- *
int mpscan_bit(const mpscan *m) { return (MPSCAN_BIT(m)); }
+/*----- Left-to right-scanning --------------------------------------------*/
+
+/* --- @mpscan_rinitx@ --- *
+ *
+ * Arguments: @mpscan *m@ = pointer to bitscanner structure
+ * @const mpw *v, *vl@ = vector of words to scan
+ *
+ * Returns: ---
+ *
+ * Use: Initializes a reverse bitscanner from a low-level
+ * vector-and-length representation of an integer. Initially no
+ * bit is ready; you must call @mpscan_rstep@ before anything
+ * useful will come out.
+ */
+
+void mpscan_rinitx(mpscan *m, const mpw *v, const mpw *vl)
+{
+ MPSCAN_RINITX(m, v, vl);
+}
+
+/* --- @mpscan_rstep@ --- *
+ *
+ * Arguments: @mpscan *m@ = pointer to bitscanner
+ *
+ * Returns: Nonzero if there is another bit to read.
+ *
+ * Use: Steps on to the next bit in the integer. The macro version
+ * evaluates its argument multiple times.
+ */
+
+int mpscan_rstep(mpscan *m) { return (MPSCAN_RSTEP(m)); }
+
+/* --- @mpscan_rbit@ --- *
+ *
+ * Arguments: @const mpscan *m@ = pointer to bitscanner
+ *
+ * Returns: The value of the current bit.
+ *
+ * Use: Reads the value of the current bit looked at by a
+ * reverse bitscanner.
+ */
+
+int mpscan_rbit(const mpscan *m) { return (MPSCAN_RBIT(m)); }
+
/*----- That's all, folks -------------------------------------------------*/