Class: FP::Fn

Inherits:
Object
  • Object
show all
Defined in:
lib/fp/fn.rb

Class Method Summary collapse

Class Method Details

.arguments(*args) ⇒ Object 



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# File 'lib/fp/fn.rb', line 16

def self.arguments(*args)
  maybe_spec = args.last

  if maybe_spec.is_a?(Hash)
    @arguments = args[0..-2]
    @spec = args.last
  else
    @arguments = args
    @spec = nil
  end

  by_name = @spec && @spec[:by] == :name
  by_position = @spec && [:pos, :position].include?(@spec[:by])
  no_spec = !@spec

  attr_readers = @arguments.map { |arg| ":#{arg}"}.join ", "

  eval "attr_reader #{attr_readers}"

  attr_assignments = @arguments.map { |arg|
    "@#{arg} = #{arg}"
  }.join("\n")

  if by_position || no_spec
    arguments_string = @arguments.join(", ")

    eval <<-EOS
      def initialize(#{arguments_string})
        #{attr_assignments}
      end
    EOS
  elsif by_name
    arguments_string = @arguments.map{ |arg| "#{arg}:"}.join(", ")
    eval <<-EOS
      def initialize(#{arguments_string})
        #{attr_assignments}
      end
    EOS
  else
    raise "Unknown value (#{@spec && @spec[:by]}) for arguments spec :by parameter; valid options are :name and :position"
  end
end

.method_added(method_name, &block) ⇒ Object 



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# File 'lib/fp/fn.rb', line 3

def self.method_added(method_name, &block)
  is_attr_reader = (@arguments || []).include?(method_name)
  is_public_method = public_instance_methods.include?(method_name)

  if !is_attr_reader && is_public_method
    eval <<-EOS
      def self.#{method_name}(*args, &block)
        new(*args, &block).#{method_name}
      end
    EOS
  end
end