txt: ## dist_zef-lancew-Scientist.md
  # DESCRIPTION
  
  Raku module inspired by <https://github.com/github/scientist> ( <http://githubengineering.com/scientist/> )
  
  See also: <https://github.com/MadcapJake/Test-Lab> For a different take on the same idea.
  
  [![test](https://github.com/lancew/ScientistP6/actions/workflows/test.yml/badge.svg)](https://github.com/lancew/ScientistP6/actions/workflows/test.yml)
  
  # SYNOPSIS
  
  ```
  flowchart LR
      raku[$exp.run]
           -->|execute| use(Control Code)
           --> compare(Compare Result)
  
      raku -->|execute| try(Candidate Code)
           --> compare(Compare Result)
  
      use --> return[Return Result]
  
      compare -->|publish| Metrics
  
  ```
  
  ```
  use Scientist;
  
  my $experiment = Scientist.new(
      experiment => 'Tree',
      try => sub {return 99},
      use => sub {return 10},
  );
  
  my $answer = $experiment.run;
  
  say "The number ten is $answer";
  warn 'There was a mismatch between control and candidate'
      if $test.result{'mismatched'};
  
  ```
  
  # Introduction
  
  This module is inspired by the Scientist ruby code released by GitHub under the MIT license in 2015/2016.
  
  In February 2016 I started writing the Perl5 module to bring similar ideas to Perl. Later I started this module to apply same ideas in Raku.
  
  Please get involved in this module; contact [lancew@cpan.org](mailto:lancew@cpan.org) with ideas, suggestions; support, etc.
  
  This code is also released under the MIT license to match the original Ruby implementation.
  
  # Methods / Attributes
  
  ## context()
  
  Provide contextual information for the experiment; will be returned in the result set.
  
  Should be a hashref
  
  ## enabled(|)
  
  DEFAULT : TRUE
  Boolean switch to enable or disable the experiment. If disabled the experiment will only return
  the control code (use) result. The candidate code (try) will NOT be executed. The results set will
  not be populated.
  
  ## experiment()
  
  Simply the name of the experiment included in the result set.
  
  ## publish
  
  Publish is a method called by ->run().
  
  Scientist is design so that you create your own personalised My::Scientist module and extend publish to do what you want/need.
  For example push timing and mismathc information to Statsd.
  
  ## use()
  
  Control code to be included in the experiment.
  This code will be executed and returned when the experiment is run.
  NB: This code is run and returned even if experiment enabed=false.
  
  ## run()
  
  This method executes the control (use) code and if experiment enabled will also run the candidate (try)
  code. The control and candidate code is run in random order.
  
  ## try()
  
  Candidate code to be included in the experiment.
  This code will be executed and discarded when the experiment is run.
  
  # Extending Publish
  
  To automate reporting of experiement results, you will want to write your own .publish() method. Publish is called by .run().
  
  A typical example would be to push timing information to Statsd or a database.
  
  ```
  use Scientist;
  
  class MyScientist is Scientist {
      has $.test_value is rw;
      method publish {
          # Do Stuff...
      }
  }
  
  my $experiment = MyScientist.new(
      experiment => 'Tree',
      enabled => True,
      try => sub {return 99},
      use => sub {return 88},
  );
  
  ```
  
  # AUTHOR
  
  Lance Wicks [lancew@cpan.org](mailto:lancew@cpan.org)
  
  # COPYRIGHT AND LICENSE
  
  This software is Copyright (c) 2016 by Lance Wicks.
  
  This is free software, licensed under:
  
  The MIT (X11) License
  
  The MIT License
  
  Permission is hereby granted, free of charge, to any person
  obtaining a copy of this software and associated
  documentation files (the "Software"), to deal in the Software
  without restriction, including without limitation the rights to
  use, copy, modify, merge, publish, distribute, sublicense,
  and/or sell copies of the Software, and to permit persons to
  whom the Software is furnished to do so, subject to the
  following conditions:
  
  The above copyright notice and this permission notice shall
  be included in all copies or substantial portions of the
  Software.
  
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT
  WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
  INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  MERCHANTABILITY, FITNESS FOR A PARTICULAR
  PURPOSE AND NONINFRINGEMENT. IN NO EVENT
  SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  CONNECTION WITH THE SOFTWARE OR THE USE OR
  OTHER DEALINGS IN THE SOFTWARE.
  
  # SEE ALSO
  
  <http://www.infoq.com/news/2016/02/github-scientist-refactoring>
  
  <http://githubengineering.com/scientist/>
  
  <https://news.ycombinator.com/item?id=11104781>
  
  <https://github.com/ziyasal/scientist.js>
  
  <http://tech-blog.cv-library.co.uk/2016/03/03/introducing-scientist/>
  