# this is the curry implementation:
class Class
  def curry(method_name, options)
    define_method(options[:as] || "#{method_name}_#{options[:with].gsub(/[^\w]/, '_')}") do |*args|
      if(method(method_name).arity == 0 && options[:with].kind_of?(Proc))
        send(method_name, *args.compact, &options[:with])
      else
        send(method_name, *[options[:with], *args].compact)
      end
    end
  end
end

# everything below is just me using it in various ways
# ----------------------------------------------------

class Foo
  curry :say,      :with => "good"
  curry :say_good, :with => "morning"
  curry :say_good, :with => "after noon"
  curry :say_good, :with => "night"

  def say(*words)
    words.join(' ')
  end
end

# using the (chained) curried methods in Foo
Foo.new.say_good_after_noon("Bob") # => "good after noon Bob"

class Fixnum
  curry :*, :with => 2, :as => 'double'
  curry :/, :with => 2, :as => 'half'
  curry :-, :with => 1, :as => 'array_index'
end

# using the curried methods in Fixnum
5.double # => 10
100.half # => 50
%w(foo bar baz)[3.array_index] # => "baz"


class Array
  curry :join, :with => ', ', :as => :csv
  curry :collect, :with => Proc.new {|x| x.name}, :as => :names
end

class String
  curry :split, :with => /\s*,\s*/, :as => :parse_csv
end

class Time
  curry :strftime, :with => "%Y-%m-%d %H:%M:%S", :as => "iso9075"
end

# easy time formatting around your app
Time.now.iso9075 # => "2008-04-17 14:11:31"

# curried methods on Array
%w(foo bar baz).csv # => "foo, bar, baz"

# curried methods in String
"foo, bar, baz".parse_csv # => ["foo", "bar", "baz"]

# and who hasn't done this: people.collect(&:name).join(', ')
class Person
  attr_accessor :name
  def initialize(name)
    self.name = name
  end
end
people = [Person.new("Rob"), Person.new("Chris"), Person.new("Pat"), Person.new("Jim")]

# instead of doing the old collect and join directly, we use their curried friends
people.names.csv # => "Rob, Chris, Pat, Jim"