Class: ExAequo::Base::Simpleton

Inherits:
Object
  • Object
show all
Defined in:
lib/ex_aequo/base/simpleton.rb

Class Method Summary collapse

Class Method Details

.new(*a, **k, &b) ⇒ Object



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# File 'lib/ex_aequo/base/simpleton.rb', line 7

def self.new(*a, **k, &b)
  names = a + k.keys
  defaults = names.zip(a.map(&None) + k.values)
  values = defaults.to_h

  Class.new do
    attr_reader *names
    attr_reader :__values__

    def to_h = __values__
    def deconstruct_keys(*) = __values__

    def merge(**keys, &blk)
      values = __values__.merge(keys, &blk)
      self.class.new(**values)
    end

    private
    define_method :initialize do |*args, **kwds, &block|
      raise ArgumentError, "spurious positional arguments #{args[a.size..].inspect}" if args.size > a.size

      spurious = kwds.keys - values.keys
      raise ArgumentError, "spurious keyword arguments #{spurious.inspect}" unless spurious.empty?

      args.each_with_index do |arg, idx|
        values[a[idx]] = arg
      end
      @__values__ = values.merge(kwds)
      __values__.each do |name, value|
        raise ArgumentError, "missing undefaulted argument #{name}" if value == None
        instance_variable_set "@#{name}", value
      end
    end
  end
end