===================================== Package "Bit::Vector" Version 6.3 ===================================== This package is available for download either from my web site at http://www.engelschall.com/u/sb/download/ or from any CPAN (= "Comprehensive Perl Archive Network") mirror server: http://www.perl.com/CPAN/authors/id/S/ST/STBEY/ Abstract: --------- Bit::Vector is an efficient C library which allows you to handle bit vectors, sets (of integers), "big integer arithmetic" and boolean matrices, all of arbitrary sizes. The library is efficient (in terms of algorithmical complexity) and therefore fast (in terms of execution speed) for instance through the widespread use of divide-and-conquer algorithms. The package also includes an object-oriented Perl module for accessing the C library from Perl, and optionally features overloaded operators for maximum ease of use. The C library can nevertheless be used stand-alone, without Perl. What's new in version 6.3: -------------------------- + Added "Create_List()" and "GCD2()" in "BitVector.c". + "new()" now can optionally return a list of bit vectors. + "GCD()" now can optionally return the two integer factors "x" and "y" for the linear combination of its input values "a" and "b" so that gcd(a,b) = x * a + y * b. + Changed the test files "t/01________new.t" and "t/09_parameters.t" as well as the documentation accordingly. + Added a new test file "t/17________gcd.t". + Further simplified the error handlers in "Vector.xs", making the resulting object library file substantially smaller (about 20%!) and thus faster to load. Legal issues: ------------- This package with all its parts is Copyright (c) 1995 - 2002 by Steffen Beyer. All rights reserved. This package is free software; you can use, modify and redistribute it under the same terms as Perl itself, i.e., under the terms of the "Artistic License" or the "GNU General Public License". The C library at the core of this Perl module can additionally be used, modified and redistributed under the terms of the "GNU Library General Public License". Please refer to the files "Artistic.txt", "GNU_GPL.txt" and "GNU_LGPL.txt" in this distribution, respectively, for details! Prerequisites: -------------- Perl version 5.000 or higher, and an ANSI C compiler. (!) ^^^^^^ If you compile under Windows, note that you will need exactly the same compiler your Perl itself was compiled with! (This is also true for Unix, but rarely a problem.) Moreover, you usually cannot build any modules under Windows 95/98, the Win 95/98 command shell doesn't grok the "&&" operator. You will need the Windows NT command shell ("cmd.exe") or the "4DOS" shell. Note that ActiveState provides precompiled binaries of this module for their Win32 port of Perl ("ActivePerl") on their web site, which you should be able to install simply by typing "ppm install Bit-Vector" in your MS-DOS command shell (but note the "-" instead of "::" in the package name!). This also works under Windows 95/98. If your firewall prevents "ppm" from downloading this package, you can also download it manually from http://www.activestate.com/ppmpackages/5.005/zips/ or http://www.activestate.com/ppmpackages/5.6/zips/. Follow the installation instructions included in the "zip" archive. Note to CPAN Testers: --------------------- After completion, version 6.3 of this module has already been tested successfully with the following configurations: Perl 5.005_03 - FreeBSD 4.1.1-RELEASE (with "dlopen() relative paths" patch) Perl 5.6.0 - FreeBSD 4.1.1-RELEASE Perl 5.6.1 - FreeBSD 4.1.1-RELEASE Perl 5.7.0 - FreeBSD 4.1.1-RELEASE Perl 5.7.1 - FreeBSD 4.1.1-RELEASE Perl 5.7.2 - FreeBSD 4.1.1-RELEASE Perl 5.8.0 - FreeBSD 4.1.1-RELEASE Perl 5.005_03 - FreeBSD 4.6-STABLE Perl 5.6.1 - FreeBSD 4.6-STABLE Perl 5.005_03 - Windows NT 4.0 & MS VC++ 6.0 (native Perl build) Perl 5.8.0 - Windows NT 4.0 & MS VC++ 6.0 (native Perl build) Perl 5.6.1 - Windows NT 4.0 & ActivePerl 5.6.1.633 (multi-thread) Installation: ------------- Please see the file "INSTALL.txt" in this distribution for instructions on how to install this package. It is essential that you read this file since one of the special cases described in it might apply to you, especially if you are running Perl under Windows. Changes over previous versions: ------------------------------- Please refer to the file "CHANGES.txt" in this distribution for a more detailed version history log. Documentation: -------------- The documentation of this package is included in POD format (= "Plain Old Documentation") in the files with the extension ".pod" in this distribution, the human-readable markup-language standard for Perl documentation. By building this package, this documentation will automatically be converted into man pages, which will automatically be installed in your Perl tree for further reference through the installation process, where they can be accessed by the commands "man Bit::Vector" (Unix) and "perldoc Bit::Vector" (Unix and Win32 alike), for example. Available man pages: Bit::Vector(3) Bit::Vector::Overload(3) Carp::Clan(3) If Perl is not available on your system, you can also read the ".pod" files ./Vector.pod ./lib/Bit/Vector/Overload.pod ./lib/Carp/Clan.pod directly. What does it do: ---------------- This module implements bit vectors of arbitrary size and provides efficient methods for handling them. This goes far beyond the built-in capabilities of Perl for handling bit vectors (compare with the method list below!). Moreover, the C core of this module can be used "stand-alone" in other C applications; Perl is not necessarily required. The module is intended to serve as a base class for other applications or application classes, such as implementing sets or performing big integer arithmetic. All methods are implemented in C internally for maximum performance. An add-on module (named "Bit::Vector::Overload") provides overloaded arithmetic and relational operators for maximum ease of use (Perl only). Note that there is (of course) a little speed penalty to pay for overloaded operators. If speed is crucial, use the "Bit::Vector" module alone! This module is useful for a large range of different tasks: - For example for implementing sets and performing set operations (like union, difference, intersection, complement, check for subset relationship etc.), - as a basis for many efficient algorithms, for instance the "Sieve of Erathostenes" (for calculating prime numbers), (The complexities of the methods in this module are usually either O(1) or O(n/b), where "b" is the number of bits in a machine word on your system.) - for shift registers of arbitrary length (for example for cyclic redundancy checksums), - to calculate "look-ahead", "first" and "follow" character sets for parsers and compiler-compilers, - for graph algorithms, - for efficient storage and retrieval of status information, - for performing text synthesis ruled by boolean expressions, - for "big integer" arithmetic with arbitrarily large integers, - for manipulations of chunks of bits of arbitrary size, - for bitwise processing of audio CD wave files, - to convert formats of data files, and more. (A number of example applications is available from my web site at http://www.engelschall.com/u/sb/download/.) A large number of import/export methods allow you to access individual bits, contiguous ranges of bits, machine words, arbitrary chunks of bits, lists (arrays) of chunks of bits or machine words and a whole bit vector at once (for instance for blockwrite/-read to and from a file). You can also import and export the contents of a bit vector in binary, hexadecimal and decimal representation as well as ".newsrc" style enumerations. Note that this module is specifically designed for efficiency, which is also the reason why its methods are implemented in C. To further increase execution speed, the module doesn't use bytes as its basic storage unit, but rather uses machine words, assuming that a machine word is the most efficiently handled size of all scalar types on all machines (that's what the ANSI C standard proposes and assumes anyway). In order to achieve this, it automatically determines the number of bits in a machine word on your system and then adjusts its internal configuration constants accordingly. The greater the size of this basic storage unit, the better the complexity (= execution speed) of the methods in this module, but also the greater the average waste of unused bits in the last word. The range of available methods is exceptionally large for this kind of library; in detail: Version() Word_Bits() Long_Bits() new() new_Hex() new_Bin() new_Dec() new_Enum() Shadow() Clone() Concat() Concat_List() Size() Resize() Copy() Empty() Fill() Flip() Primes() Reverse() Interval_Empty() Interval_Fill() Interval_Flip() Interval_Reverse() Interval_Scan_inc() Interval_Scan_dec() Interval_Copy() Interval_Substitute() is_empty() is_full() equal() Lexicompare() Compare() to_Hex() from_Hex() to_Bin() from_Bin() to_Dec() from_Dec() to_Enum() from_Enum() Bit_Off() Bit_On() bit_flip() bit_test() Bit_Copy() LSB() MSB() lsb() msb() rotate_left() rotate_right() shift_left() shift_right() Move_Left() Move_Right() Insert() Delete() increment() decrement() inc() dec() add() subtract() Negate() Absolute() Sign() Multiply() Divide() GCD() Power() Block_Store() Block_Read() Word_Size() Word_Store() Word_Read() Word_List_Store() Word_List_Read() Word_Insert() Word_Delete() Chunk_Store() Chunk_Read() Chunk_List_Store() Chunk_List_Read() Index_List_Remove() Index_List_Store() Index_List_Read() Union() Intersection() Difference() ExclusiveOr() Complement() subset() Norm() Min() Max() Multiplication() Product() Closure() Transpose() Note to C developers: --------------------- Note again that the C library at the core of this module can also be used stand-alone (i.e., it contains no inter-dependencies whatsoever with Perl). The library itself consists of three files: "BitVector.c", "BitVector.h" and "ToolBox.h". Just compile "BitVector.c" (which automatically includes "ToolBox.h") and link the resulting output file "BitVector.o" with your application, which in turn should include "ToolBox.h" and "BitVector.h" (in this order). Example applications: --------------------- See the module "Set::IntRange" for an easy-to-use module for sets of integers within arbitrary ranges. See the module "Math::MatrixBool" for an efficient implementation of boolean matrices and boolean matrix operations. (Both modules are also available from my web site at http://www.engelschall.com/u/sb/download/ or any CPAN server.) See the file "SetObject.pl" in the "examples" subdirectory of this distribution for a way to emulate the "Set::Object" module from CPAN using "Bit::Vector" - this is a way to perform set operations on sets of arbitrary objects (any Perl objects or Perl data structures you want!). An application relying crucially on this "Bit::Vector" module is "Slice", a tool for generating different document versions out of a single master file, ruled by boolean expressions ("include english version of text plus examples but not ..."). (See also http://www.engelschall.com/sw/slice/.) This tool is itself part of another tool, "Website META Language" ("WML"), which allows you to generate and maintain large web sites. Among many other features, it allows you to define your own HTML tags which will be expanded either at generation or at run time, depending on your choice. (See also http://www.engelschall.com/sw/wml/.) Both tools are written by Ralf S. Engelschall. Credits: -------- Please refer to the file "CREDITS.txt" in this distribution for a list of contributors. Author's note: -------------- If you have any questions, suggestions or need any assistance, please let me know! Please do send feedback, this is essential for improving this module according to your needs! I hope you will find this module useful. Enjoy! Yours, -- Steffen Beyer http://www.engelschall.com/u/sb/ "There is enough for the need of everyone in this world, but not for the greed of everyone." - Mohandas Karamchand "Mahatma" Gandhi