* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
- * $Id: bitmatch.mli,v 1.20 2008-05-08 21:28:28 rjones Exp $
+ * $Id$
*)
(**
This function is inefficient. In the best case when the bitstring
is nicely byte-aligned we do a [String.sub] operation. If the
bitstring isn't aligned then this involves a lot of bit twiddling
- and is particularly inefficient. *)
+ and is particularly inefficient.
+
+ If the bitstring is not a multiple of 8 bits wide then the
+ final byte of the string contains the high bits set to the
+ remaining bits and the low bits set to 0. *)
+
+val bitstring_to_file : bitstring -> string -> unit
+(** [bitstring_to_file bits filename] writes the bitstring [bits]
+ to the file [filename]. It overwrites the output file.
+
+ Some restrictions apply, see {!bitstring_to_chan}. *)
+
+val bitstring_to_chan : bitstring -> out_channel -> unit
+(** [bitstring_to_file bits filename] writes the bitstring [bits]
+ to the channel [chan].
+
+ Channels are made up of bytes, bitstrings can be any bit length
+ including fractions of bytes. So this function only works
+ if the length of the bitstring is an exact multiple of 8 bits
+ (otherwise it raises [Invalid_argument "bitstring_to_chan"]).
+
+ Furthermore the function is efficient only in the case where
+ the bitstring is stored fully aligned, otherwise it has to
+ do inefficient bit twiddling like {!string_of_bitstring}.
+
+ In the common case where the bitstring was generated by the
+ [BITSTRING] operator and is an exact multiple of 8 bits wide,
+ then this function will always work efficiently.
+*)
(** {3 Printing bitstrings} *)