The original code is © copyright 1995 by Miller Freeman, Inc.
ANSI C functions to create and manipulate arrays of bits, i.e. bit vectors. Functions to: dynamically create arrays, access (read and write) elements; convert from numbers to bit vectors and bit vectors to strings. Additional mathematical functions (union, intersection, complement, number of set bits) are provided that are more efficient than naïve implementations.
The module was designed to be robust enough to work with machines
of different word sizes. Only a couple of minor changes are required to
change it from using unsigned char for `bits' to
another integral type. See ba_init() and the definition of
BITS_SZ for details.
Only minimal optimization has been attempted.
A version of this code appeared in Dr. Dobb's Journal #233 (August 1995) Volume 20 Issue 8 in an article entitled Implementing Bit Vectors in C by James Blustein. The article is on pages 42, 44 and 46. The original code is on pages 96, 98-100.
The code at the DDJ FTP site (and, presumably, on the diskette) is incorrect and not as published. I told them about it when the article was first published but, as of one year later, nothing has changed.
My address has changed since the publication in DDJ. Please do not send mail to <jamie@uwo.ca> anymore. Instead use <jamie@cs.dal.ca>.
This bitvector code consists of three files:
The original code is (c) copyright 1995 by Miller Freeman, Inc.