                    =====================================
                      Package "Bit::Vector" Version 6.3
                    =====================================


                 Copyright (c) 1995 - 2002 by Steffen Beyer.
                             All rights reserved.


Version history:
----------------

Version 6.3   28.09.2002

 +  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.

Version 6.2   15.09.2002

 +  Fixed missing "\" in regular expression in "t/00____version.t".
 +  Overhauled the error handlers in "BitVector.c" and "Vector.xs".
 +  Added a demo "examples/test.c" to play around with the C library.
 +  Attempted to fix all compiler warnings.
 +  Fixed a problem in test "t/01________new.t" with Perl using
    64 bit integers; now contains "use integer;" to avoid failure.
 +  Synchronized "Carp::Clan" and "ToolBox.h" with "Date::Calc" 5.2.
 +  Revealed common method aliases (Or, And, etc.) in the documentation.
 +  Fixed GCD(), now GCD(z,0) == GCD(0,z) == z and negative values
    are handled correctly.

Version 6.1   08.10.2001

 +  Fixed the problem which caused some of the tests with overloaded
    operators to fail under Perl 5.7.1 and Perl 5.7.2.
 +  Added the module "Carp::Clan" to the distribution.
 +  Changed most of the error messages in Bit::Vector::Overload.
 +  Changed the test script "t/30_overloaded.t" accordingly.
 +  Changed "Makefile.PL" to write a "patchlevel.h" file so that
    "Vector.xs" can automatically detect the Perl version and
    whether to use the macro PL_na or na, GIMME_V or GIMME.
    Tweaking the code before installing is not necessary anymore.
 +  Changed the documentation in files README.txt and INSTALL.txt
    accordingly.
 +  Changed the internal names BitVector_msb and BitVector_lsb to
    BitVector_msb_ and BitVector_lsb_ in order to make the (non-
    ANSI C-standard-compliant!) VMS linker happy. This does NOT
    affect the Perl interface, though.

Version 6.0   08.10.2000

 +  Splitted the Vector.pm module; separated XS and overloaded Perl
    part for improved performance (reduces loading time for XS part).
 +  Corrected the handling of numerical overflow in arithmetic methods
    ("add()", "subtract()", "Multiply()", "from_Dec()", "new_Dec()").
 +  Methods "add()" and "subtract()" now return the carry as well as
    the overflow flag if called in list context (only the carry in
    scalar context, as before).
 +  Added two new methods "inc()" and "dec()", which return the overflow
    flag (whereas "increment()" and "decrement()" return the carry flag).
    The new methods also allow to copy-and-increment/decrement in addition
    to in-place operation.
 +  Methods "from_Dec()" and "new_Dec()" now allow you to enter large
    positive numbers which will have the MSB set (this was forbidden
    previously because these numbers are considered to be negative in
    two's complement binary representation).

Version 5.8   14.07.2000

 +  Changed "na" to "PL_na" in Vector.xs in order to make the module
    ready for Perl 5.6.0.
 +  Removed the error messages which appeared at global destruction
    time with Perl 5.6.0.
 +  Changed the corresponding test script (t/02____destroy.t) accordingly.
 +  Optimized the "strEQ" away from the typemap section in Vector.xs.
 +  Fixed the misspelled word "whether" in the documentation.
 +  Added method "Power()".
 +  Added overloaded operator "**" (for exponentiation).
 +  Changed method "Copy()"; the two vectors do not need to have the same
    size anymore. The method will copy as much as will fit or fill up
    with 0's or 1's (depending on the sign of the source) if necessary.
 +  Changed the corresponding test script (t/09_parameters.t) accordingly.

Version 5.7   19.05.1999

 +  Improved method "Div_Pos()": It now uses only one instead of the
    former two (very costly) "shift" operations in its main loop, and
    it now depends on the (variable) length of the numbers involved rather
    than the (constant) length of their respective bit vectors, making
    this method tremendously faster now. The methods "to_Dec()", "Divide()"
    and "GCD()" also profit from this change in the same way since they
    rely crucially on the "Div_Pos()" method, internally.
 +  Added a matrix multiplication method (for "Math::MatrixBool") named
    "Product()" which determines paths in matrices representing graphs.
 +  Fixed the problems with anchored error messages in the regression
    test suite under MacPerl.

Version 5.6   02.11.1998

 +  Removed the leading zeros from the output of "to_Hex()".
 +  Fixed compiler warning on line 2067 of "BitVector.c".

Version 5.5   21.09.1998

 +  Fixed the bug of the uninitialized return code in method "Multiply()".
 +  Fixed the failure of tests 96-131 of test script "t/01________new.t"
    under HP-UX 10.

Version 5.4   07.09.1998

 +  Fixed the bug of the uninitialized return code in method "Divide()".
 +  Introduced an additional header "Preface" in the POD documentation to
    avoid clobbering of the information displayed by CPAN.pm et al.
 +  Added the new attributes to "Makefile.PL" for ActiveState's port
    of Perl 5.005 to the Win32 platform.

Version 5.3   12.05.1998

 +  Changed "Norm()" to become still a bit more efficient.
 +  Ported the "upgrade_BV52" utility to Perl ("upgrade_BV53.pl"),
    making it faster, more flexible and easier to read and maintain.
 +  Added "upgrade_BV42.pl".
 +  Enhanced support for Windows NT/95.
 +  Complete rewrite of this "CHANGES.txt" document.

Version 5.2   31.03.1998

 +  Changed "Norm()", "<<" and ">>" to become more efficient.
 +  Added "new_Hex()", "new_Bin()", "new_Dec()" and "new_Enum()".
 +  Made the exception handling in "Vector.pm" more elegant.

Version 5.1   09.03.1998

 +  Added systematic exception handling to "Vector.pm".

Version 5.0   01.03.1998

 +  "Outsourced" all example modules (now available separately).
 +  Added: Word_Bits(), Long_Bits(), Concat(), Concat_List(), Primes(),
    Reverse(), Interval_Reverse(), Interval_Copy(), Interval_Substitute(),
    Lexicompare(), to_Bin(), from_Bin(), to_Dec(), from_Dec(), Bit_Copy(),
    LSB(), MSB(), lsb(), msb(), Insert(), Delete(), add(), subtract(),
    Negate(), Absolute(), Sign(), Multiply(), Divide(), GCD(), 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(), Transpose().
 +  Ported to C: "Version()", "Shadow()", "Clone()", "to_Enum()",
    "from_Enum()".
 +  Changed: "Compare()" (now assumes bit vectors are SIGNED).
 +  Renamed: "to_String()" ==> "to_Hex()", "from_string()" ==> "from_Hex()",
    "to_ASCII()" ==> "to_Enum()", "from_ASCII()" ==> "from_Enum()"
    (aliases are still available but deprecated).
 +  Dropped: "lexorder()", "new_from_String()".
 +  Dropped: Module "Set::IntegerFast" (replaced by "Bit::Vector").
 +  Definitely abandoned the possibility for subclassing because it doesn't
    make any sense in this module (use embedding instead!).
 +  Fixed: Module "Set::IntegerRange" version 4.2 broke with "Bit::Vector"
    version 5.0. Issued quick fix "Set::IntRange" version 5.0. More
    thorough implementation is under construction.

Version 4.2   16.07.1997

 +  Added "is_empty()" and "is_full()".

Version 4.1   30.06.1997

 +  Added "Move_Left()" and "Move_Right()".
 +  Changed "<<" and ">>" to call "Move_Left()" and "Move_Right()" instead.
 +  Added "increment()" and "decrement()".
 +  Changed "++" and "--" to call "increment()" and "decrement()" instead.
 +  Added "Resize()", "Interval_Scan_inc()", "Interval_Scan_dec()" and
    "BitVector()" to "Set::IntegerRange".

Version 4.0   23.04.1997

 +  Complete rewrite of the "Set::IntegerFast" module.
 +  Renamed "Set::IntegerFast" to "Bit::Vector".
 +  United the separate C cores and XS files for sets, matrices of booleans
    and bit shift operations in a single module.
 +  Abandoned the individual version numbers.
 +  Dropped the separate "Makefile.PL"s, adopted the solution using
    a "lib" subdirectory.
 +  Added: Flip(), Interval_Scan_inc(), Interval_Scan_dec(), rotate_left(),
    rotate_right(), shift_left(), shift_right(), to_String(), from_string(),
    Multiplication(), Closure(), Shadow(), Clone(), new_from_String(),
    to_ASCII(), from_ASCII().
 +  Added overloaded operators for: emptyness, equality, lexical comparison,
    shift register, rotate register, string conversion, union, intersection,
    difference, exclusive-or, complement, subset relationship, true subset
    relationship, superset relationship, true superset relationship, norm.

Version 3.2   04.02.1997

 +  Added "Empty_Interval()", "Fill_Interval()", "Flip_Interval()" and
    "Size()" to "Set::IntegerFast" and "Set::IntegerRange".
 +  "Set::IntegerFast" and "Set::IntegerRange" both switched to version
    number 3.0.
 +  Improved the "Math::MatrixBool" module (new version number: 2.0) to
    use C routines for matrix multiplication and closure and fixed some
    bugs in these methods at the same time.
 +  Added "new_from_string()" and "Dim()" to "Math::MatrixBool".
 +  Fixed a severe bug in the "kleene()" method of "Math::MatrixReal"
    (new version number: 1.1).

Version 3.1   21.01.1997

 +  Fixed a bug that caused the initialization routine of the module to fail
    on 64 bit machines due to a wrong conditional expression (type "int" and
    "size_t" do not necessarily have the same size!).
 +  "Set::IntegerFast" switched to version number 2.2.

Version 3.0   12.01.1997

 +  Added "flip()" to "Set::IntegerFast" and "Set::IntegerRange".
 +  Transformed the "kruskal" demo program to a Perl module "Graph::Kruskal".
 +  Added new companion modules: "Math::MatrixBool", "Math::MatrixReal" and
    "DFA::Kleene", all with separate "Makefile.PL"s.
 +  Added introductory article about theory behind Kleene's algorithm.
 +  Introduced independent version numbers for all modules:
    "Set::IntegerFast" ==> version 2.1, "Set::IntegerRange" ==> version 2.0.
 +  Added overloaded operators to "Set::IntegerRange".
 +  Bugfix: Changed "gv_stashpv(class,0)" to "gv_stashpv(class,1)" in the
    XS file (caused core dumps in previous versions when "new()" was called
    with a nonexistent class name and subclassing enabled).

Version 2.0   14.12.1996

 +  Changed "Create()" to "new()".
 +  Now supports "$set = new Set::IntegerFast($elements);" instead of
    "$set = Set::IntegerFast::Create($elements);".
 +  Changed "Destroy()" to "DESTROY()", which doesn't need to (and
    shouldn't!) be called explicitly anymore.
 +  Fixed the "bad free() ignored" warnings caused by "Destroy()" in
    version 1.1 (in conjunction with Perl version 5.002) which led some
    of the tests in "make test" to fail.
 +  Complete rewrite of the XS part.
 +  Changed "lexorder()" and "Compare()" to become more efficient
    (complexity n/b instead of n/8).
 +  Changed parameters visible externally from "word"/"unit" to "N_int"
    in the C core.
 +  Complete rewrite of the documentation, now in POD format.
 +  Added a new (wrapper) module named "Set::IntegerRange".

Version 1.1   08.01.1996

 +  Added "Resize()".
 +  Changed "Create()", "Empty()", "Fill()" and "Copy()" to have complexity
    n/b rather than n/8.
 +  Made interfaces in C core more consistent: Pointer to a set object is
    now always the first parameter.
 +  Added new paragraphs to the documentation.
 +  Added "ExclusiveOr()" (for symmetric difference X = (Y + Z) \ (Y * Z)).

Version 1.0   14.12.1995   First version under UNIX (with Perl module).

 +  Initial release as a C library and Perl module.

Version 0.9   01.11.1993   First version of C library under MS-DOS.

 +  Ported the Pascal code to C because I thought sets of arbitrary sizes
    are always useful to have.

Version 0.1   ??.??.1989   First version in Turbo Pascal under CP/M.

 +  I first wrote this library (on my Apple ][+) because I needed more bits
    in a set than Turbo Pascal would support in order to calculate "first",
    "follow" and "look-ahead" character sets for a compiler-compiler.

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