Loverload

DSL for building method overloading in Ruby.

Rigid language like Java allow you to create method overloading:

public void draw(String s) {
    ...
}
public void draw(int i) {
    ...
}
public void draw(double f) {
    ...
}
public void draw(int i, double f) {
    ...
}

However, in Ruby, we don't have this kind of thing, do we?

before_save NameSayer.new
before_save :say_my_name
before_save {|record| puts "My name is #{record.name}" }
before_save 'puts "My name is #{self.name}"'

An Intervention for ActiveRecord by Ernie Miller

Installation

Add this line to your application's Gemfile:

gem 'loverload'

And then execute:

$ bundle

Or install it yourself as:

$ gem install loverload

Usage

Simple

class Dummy
  include Loverload

  def_overload :hello do
    with_params do
      "Hello Nobody"
    end

    with_params do |name|
      "Hello #{ name }"
    end

    with_params do |name, age|
      "Hello #{ name } Age #{ age }"
    end
  end
end

dummy = Dummy.new
dummy.hello #=> 'Hello Nobody'
dummy.hello('Teja') #=> 'Hello Teja'
dummy.hello('Teja', 21) #=> 'Hello Teja Age 21'

Strict

class Dummy
  include Loverload

  def_overload :hello do
    with_params String do |name|
      "Hello Name: #{ name }"
    end

    with_params Fixnum do |age|
      "Hello Age: #{ age }"
    end

    with_params String, Fixnum do |name, age|
      "Hello Name: #{ name } Age: #{ age }"
    end

    with_params Fixnum, String do |age, name|
      "Hello Age: #{ age } Name: #{ name }"
    end
  end
end

dummy = Dummy.new
dummy.hello('Teja') #=> 'Hello Name: Teja'
dummy.hello(21) #=> 'Hello Age: 21'
dummy.hello('Teja', 21) #=> 'Hello Name: Teja Age: 21'
dummy.hello(21, 'Teja') #=> 'Hello Age: 21 Name: Teja'
dummy.hello('Teja', 21, true) #=> NoMethodError

This is how you do :before_save

class Dummy
  include Loverload

  def_overload :before_save do
    with_params Dummy do |dummy|
      "Puke rainbow"
    end

    with_params Symbol do |symbol|
      "Puke more rainbow"
    end

    with_params Proc do |proc|
      "Puke rainbow and leprechaun"
    end

    with_params String do |string|
      "Puke rainbow, leprechaun, and gold"
    end
  end
end

dummy = Dummy.new
dummy.before_save(Dummy.new) #=> "Puke rainbow"
dummy.before_save(:symbol) #=> "Puke more rainbow"
dummy.before_save(proc{|this| is proc}) #=> "Puke rainbow and leprechaun"
dummy.before_save('string') #=> "Puke rainbow, leprechaun, and gold"

TODO

• Make it less ugly

Contributing

1. Fork it
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