Streamable
Allows you to stream data through a set of functions (Think point-free programming):
# Make sure to include Streamable
[0] pry(main)> include Streamable
# Same as Float(1)
[1] pry(main)> stream 1, :Float
=> 1.0
# Same as Integer(p(Float(1)))
[2] pry(main)> stream 1, :Float, :p, :Integer
1.0
=> 1
# Same as -> i { i * 5 }[Float(1)]
[3] pry(main)> stream 1, :Float, -> i { i * 5 }
=> 5.0Multistream lets you do this with multiple sets of initial data:
# Same as ->(a,b) { a * b }[1,2]
[4] pry(main)> multistream data: [1,2], methods:[->(a,b) { a * b }]
=> 2How does it work?
So what is this even doing? We've seen unix pipes:
echo 'foo' | grep fWe're essentially piping the output of one command to another. So let's go back to Ruby:
stream(1, :Float)This is passing the number one in as the first argument to the Kernel#Float method, or rather Float(1). What happens as we add more to it?
stream(1, :Float, :p)Now we're doing the same thing as before, and getting Float(1), and then sending that result into the Kernel#p function, such that we now effectively have p(Float(1)) or p(1.0) if we evaluate the float.
So how does that happen in Ruby? With Enumerable#reduce:
n = 1
methods = [:Float, :p]
# We're reducing with the initial value of n, which is now in data inside the block
methods.reduce(n) { |data, method|
# Now we call the method from the Kernel and pass it the data as the first argument.
# As the value of data is set to the last return value of the block, this will fold over
# the original value of data with the result of method(data) and will continue to cycle
# through the remaining methods.
Kernel.send(method, data)
} # Which gives us our value, and a nice faux pipe stream / point-free programming implementation.Installation
Add this line to your application's Gemfile:
gem 'streamable'
And then execute:
$ bundle
Or install it yourself as:
$ gem install streamable
Contributing
- Fork it ( http://github.com/baweaver/streamable/fork )
- Create your feature branch (
git checkout -b my-new-feature) - Commit your changes (
git commit -am 'Add some feature') - Push to the branch (
git push origin my-new-feature) - Create new Pull Request