Revision history for Algorithm-Combinatorics

    * Added derangements(), code, tests, and docs.

    * Benchmarked permutations() against permutations() with loop
      variables declared as registers. No measurable difference.

    * Removed "install" from the cpan(1) example in README.

0.12 November 13 2005

    * DESCRIPTION was reworded.

    * Refactored as regular XS-based module.

0.11 November 8 2005

    * CPAN.pm does not resolve the dependency with Inline before
      Makefile.PL is executed, and it fails to generate the Makefile
      because the module Inline::MakeMaker is not found. Due to this
      ExtUtils::MakeMaker is back.

0.10 November 6 2005

    * permutations() has been edited to match Algorithm L from [1]

    * Added REFERENCES to POD

    * Added a workaround to Makefile.PL for "No rule to make target
      ... needed by `pure_all'" so that the Makefile generated by
      Inline::MakeMaker's WriteInlineMakefile() works, and thus the
      C part behaves like a plain XS extension instead of generating
      caches on the user machine

0.08 November 6 2005

    * Changed hyphens in test filenames with underscores

    * The module is known to run under 5.6.2, so the corresponding
      use VERSION has been added

    * variations(\@data, $k) is delegated to permutations(\@data) for
      @data == $k, since permutations() is more efficient

    * Changed AV* in signatures to SV* plus a cast (SV*) SvRV(array) due
      to problems reported regarding AVPtrs. I copied the trick from the
      Changes of Digest::SHA. (Thanks to Aaron Dalton for reporting the
      problem.)

    * variations() is much better, almost twice as fast and does not
      create SVs

0.07 November 5 2005

    * Documented the corresponding formulas

    * Slicing is done now in Perl. The code is much more clear and in my
      benchmarks no significant difference is measured

    * The iterator now may receive an initial arrayref (this is private
      implementation), which simplifies the set up of the iterator when
      the first tuple is known

0.06 November 5 2005

    * permutations() is about 3-4 times faster

0.05  November 4 2005

    * Rewrote the test suite, and relevant documentation

    * Added the helper module t/Tester.pm to factor out a common test
      code pattern

    * If k is "out of natural range"" the empty set is returned and a
      warning is issued

    * The iterators return an arrayref, and the implementation was
      revised accordingly to be mathematically correct in edge-cases and
      more forgiving

    * I can't stand that DIAGNOSTICS::Errors section, so many croaks on
      boundary conditions are so unperlish! The module has just a couple
      of days so I am on time to fix this

0.02  November 3 2005

    * README revised

    * DEPENDENCIES added to POD

    * DIAGNOSTICS added to POD

    * VERSION added to POD

    * Added some code documentation

    * Minor tweaks on the XS code

0.01  November 2 2005

    * First version, released on an unsuspecting world.