Ramda Ruby

This is a ruby version of Ramda Js library.

Information

This library uses some stuff like curry and __ which reduces performance. Please review benchmarks section.

Installation

Add this line to your application's Gemfile:

gem 'ramda-ruby'

And then execute:

$ bundle

Or install it yourself as:

$ gem install ramda-ruby

And then require:

require 'ramda'

Documentation

• Function
• List
• Logic
• Math
• Object
• Relation
• String
• Type

You can use Ramda docs as a documentation or to check Ruby examples.

Algebraic structures

Methods which supports algebraic types:

• ap
• both
• chain
• complement
• either
• lift
• lift_n
• map
• pluck

Supported libraries (comparison):

• dry-monads
• kleisli

dry-monads

works with ruby >= 2.1

kleisli works from this fork:

gem 'kleisli', git: 'git@github.com:lazebny/kleisli.git', branch: 'ramda-ruby'

Differences:

• txus/kleisli#28
• txus/kleisli#29

Usage

Pointless Style:

  R = Ramda

  players = [
    { name: 'Andrey', score: 100 },
    { name: 'Ivan', score: 200 },
    { name: 'Masha', score: 150 }
  ]

  best_player = R.pipe(R.sort_by(R.prop(:score)), R.reverse, R.head, R.prop(:name))
  best_player.call(players) # Ivan

Placeholder:

  reset_to_default = R.merge(R.__, x: 0)
  reset_to_default.call(x: 5, y: 2) # { x: 0, y: 2 }

Transducers:

  appender = R.flip(R.append)

  xform = R.map(R.add(10))
  R.transduce(xform, appender, [], [1, 2, 3, 4]) # [11, 12, 13, 14]

  xform = R.filter(:odd?.to_proc)
  R.transduce(xform, appender, [], [1, 2, 3, 4]) # [1, 3]

  xform = R.compose(R.map(R.add(10)), R.take(2))
  R.transduce(xform, appender, [], [1, 2, 3, 4]) # [11, 12]

  xform = R.compose(R.filter(:odd?.to_proc), R.take(2))
  R.transduce(xform, R.add, 100, [1, 2, 3, 4, 5]) # 104)
  R.transduce(xform, appender, [], [1, 2, 3, 4, 5]) # [1, 3])
  R.into([], xform, [1, 2, 3, 4, 5]) # [1, 3])

With algebraic structures:

  # ap
  R.ap(R.ap(Maybe.of(R.add), Maybe.of(3)), Maybe.of(5)) # Some(8)

  # chain
  R.chain(->(x) { Maybe.of(R.add(5, x)) }, Maybe.of(3)) # Some(8)

  # map
  R.map(R.add(3), Maybe.of(5)) # Some(8)

  # lift
  add_m = R.lift(R.add)
  add_m.call(Maybe.of(3), Maybe.of(5)) # Some(8)

  # lift_n
  add_m = R.lift_n(3, -> (a, b, c) { a + b + c })
  add_m.call(Maybe.of(3), Maybe.of(5), Maybe.of(10)) # Some(18)

Change exceptions handler:

  # To use a default 'with_narrow' handler:
  Ramda.exception_handler = nil
  # the same as:
  Ramda.exception_handler = -> Ramda::ExceptionHandler.method(:with_narrow)

  # Set a custom handler:
  Ramda.exception_handler = -> (e, _method_name) { raise e, e.exception, e.backtrace }
  # the same as:
  Ramda.exception_handler = -> Ramda::ExceptionHandler.method(:default)

Ramda in debug mode shows calls trace. Notice: trace is shown only for Ramda functions and not for regular procs. If you want to show a whole trace you can wrap your proc in Ramda.curry function (pleaes see example below).

Enable debug mode:

  Ramda.debug_mode = true

  # Example:

  Ramda.filter(Ramda.curry(:even?.to_proc, [1, 2, 3, 4])

  # -> curry(#<Proc:0x...@/srv/app/spec/ramda/list_spec.rb:130 (lambda)>) # #<Proc:0x... (lambda)>
  # -> curry(1) # false
  # -> curry(2) # true
  # -> curry(3) # false
  # -> curry(4) # true
  # -> filter(#<Proc:0x0055ff3fad4640 (lambda)>, 1, 2, 3, 4) # [2, 4]

Resources

• Cleaner Ruby validations using the Either monad and Kleisli gem

Benchmarks

• Function
• List
• Logic
• Math
• Object
• Relation
• String
• Type

Send all results to STDOUT

bundle exec rake ramda:run_benchmark

Send one function type results to STDOUT

bundle exec rake ramda:run_benchmark[bench/list/*]

Update all files in bench_results

bundle exec rake ramda:run_benchmark_to_file

Update one type of function in bench_results

bundle exec rake ramda:run_benchmark_to_file[bench/list/*]

Development

You can use either regular approach with installing gems on local machine or with docker-compose which is handy when you are playing with ruby versions.

With docker-compose:

1. Install Docker
2. Install Docker Compose
3. Run tests

touch .bashrc.docker .pry_history.docker
docker-compose run --rm app bash
bundle
rspec

To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Make changes
4. Check with Rubocop and resolve all issues(rubocop -aD)
5. Commit your changes (git commit -am 'Add some feature')
6. Push to the branch (git push origin my-new-feature)
7. Create new Pull Request

License

The gem is available as open source under the terms of the MIT License.