schlib is a library with selected useful classes.

Installation

Add this line to your application's Gemfile:

gem 'schlib'

And then execute:

$ bundle

Or install it yourself as:

$ gem install schlib

Usage

This gem consists of several helper classes. Require them and use them.

Cache

Cache helps to cache long running computations or I/O. It acts similar to Rails' cache and persists to a file. It is only possible to cache simple data structures like Array, String, Integer, etc...

require 'schlib/cache'

c = Schlib::Cache.new('/tmp/my_cache_file.tmp')

def calc_pi(n)
  # this caclulation of pi may not be correct :D
  if n <= 1
    4.0
  elsif n.even?
    calc_pi(n - 1) + 4.0 / (n * 2 + 1)
  elsif n.odd?
    calc_pi(n - 1) - 4.0 / (n * 2 + 1)
  end
end

def precise_pi
  c.cache(:precise_pi) do
    calc_pi 100_000_000_000
  end
end

precise_pi # first call takes long time
precise_pi # successive calls are fast

Command

Command is a wrapper around ruby's backticks and enables logging and raising exceptions on bad exitcodes.

require 'logger'
require 'schlib/command'

c0 = Schlib::Command.new
c0.run 'wtf', approve_exitcode: true
# ScriptError: COMMAND FAILED!
# from /home/schasse/code/schlib/lib/schlib/command.rb:15:in `run'

l = Logger.new(STDOUT).tap { |l| l.level = Logger::DEBUG }
c1 = Command.new l

c1.run 'wtf???'
# D, [2017-01-28T11:51:08.387088 #29538] DEBUG -- : wtf???
# D, [2017-01-28T11:51:08.388694 #29538] DEBUG -- : sh: 1: wtf???: not found
#
# => "sh: 1: wtf???: not found\n"

Spinner

Have a long running command? Use spinner to entertain.

require 'schlib/spinner'

Schlib::Spinner.wait_for do
  sleep 2
  return 'well-rested'
end
# Loading ▇ ... done
#
# => "well-rested"

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. 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

Bug reports and pull requests are welcome on GitHub at https://github.com/schasse/schlib. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

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