Ripar

Think riparian. Think old man river, he jus' keep on rollin'. Think rive. Also river, reaver, repair, reaper.

Tear chained method calls apart, put them in a block, and return the block value. eg

Before:

  result = values.select{|x| x.name =~ /Jo/}.map{|x| x.count}.inject(0){|s,x| s + x}

After:

  result = values.rive do
    select{|x| x.name =~ /Jo/}
    map{|x| x.count}
    inject(0){|s,x| s + x}
  end

This is also a little different to instance_eval, because the following will work:

  outside_block_regex = /Wahoody-hey/

  result = values.rive do
    select{|x| x.name =~ outside_block_regex}
    map{|x| x.count}
    inject(0){|s,x| s + x}
  end

Warning this can have some rare but weird side effects:

• will probably break on classes that have defined method_missing, but not respond_to_missing
• an outside variable with the same name as an inside method taking in-place hash argument will cause a syntax error.

But you can obviate all of that by just using the safe syntax:

  outside_block_regex = /Wahoody-hey/

  result = values.rive do |vs|
    vs.select{|x| x.name =~ outside_block_regex}
    vs.map{|x| x.count}
    vs.inject(0){|s,x| s + x}
  end

Or using the magic disambiguaters:

  select = /Wahoody-hey/

  result = values.rive do
    __inside__.select{|x| x.name =~ __outside__.select}
    map{|x| x.count}
    inject(0){|s,x| s + x}
  end

Installation

Add this line to your application's Gemfile:

gem 'ripar'

And then execute:

$ bundle

Or install it yourself as:

$ gem install ripar

Usage

In your class

class YourChainableThing
  include Ripar
end

yct = YourChainableThing.new.rive do
  # operations
end

In a singleton

o = Object.new
class << o
  include Ripar
end

The mostest lightweightiest

o = Object.new.extend(Ripar)

Monkey-patch

class Object
  include Ripar
end

Contributing

The standard github pull request dance:

1. Fork it ( http://github.com//ripar/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

PS

Thing = Struct.new :name, :count
values = [
  Thing.new('John', 20),
  Thing.new('Joe', 7),
  Thing.new('Paul', 3),
  Thing.new('James', 3),
  Thing.new('Wahoody-heydi-dude', 3.141527),
]