Fast estimation of number representation lengths.

[u/mdw/catacomb] / mptext.h

diff --git a/mptext.h b/mptext.h
index db4e591..57c4dc2 100644 (file)
--- a/mptext.h
+++ b/mptext.h
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: mptext.h,v 1.5 2000/10/08 12:04:58 mdw Exp $
+ * $Id: mptext.h,v 1.6 2002/10/15 22:58:29 mdw Exp $
  *
  * Textual representation of multiprecision numbers
  *
@@ -30,6 +30,9 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: mptext.h,v $
+ * Revision 1.6  2002/10/15 22:58:29  mdw
+ * Fast estimation of number representation lengths.
+ *
  * Revision 1.5  2000/10/08 12:04:58  mdw
  * (MP_DOFPRINTFR): cope with null pointers.
  *
@@ -107,6 +110,20 @@ extern mp *mp_read(mp */*m*/, int /*radix*/,
 extern int mp_write(mp */*m*/, int /*radix*/,
                    const mptext_ops */*ops*/, void */*p*/);
 
+/* --- @mptext_len@ --- *
+ *
+ * Arguments:  @mp *x@ = number to work on
+ *             @int r@ = radix the number will be expressed in
+ *
+ * Returns:    The number of digits needed to represent the number in the
+ *             given base.  This will not include space for a leading sign
+ *             (use @MP_ISNEG@ to check that, or just add one on for luck);
+ *             neither will it add space for a terminating null.  In general
+ *             the answer will be an overestimate.
+ */
+
+extern size_t mptext_len(mp */*x*/, int /*r*/);
+
 /*----- File I/O ----------------------------------------------------------*/
 
 #include <stdio.h>