Method: Injector#inject

Defined in:
lib/injector.rb

#inject(overrides = {}, &block) ⇒ Object 



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# File 'lib/injector.rb', line 43

def inject(overrides = {}, &block)
  params = []
  keys = {}
  block.parameters.each_with_index do |(type, value), index|
    raise(
      ArgumentError,
      [
        "splash operator arguments are not permitted when injecting.",
        ":#{value} in #{ block.source_location }"
      ].join(" ")
    ) if type == :rest or type == :keyrest

    # fetch by index first! e.g. inject(0 => 40) { |x| x + 2 }
    result = overrides.fetch(index) do
      # then fetch by value
      overrides.fetch(value) do
        # Unfortunately, optional arguments are not possible, as
        # a Ruby block passed to `inject` will have exclusively optional arguments.
        # Instead, key arguments introduced in Ruby 2.0 should be used.
        if type == :key
          begin self.get(value)
          rescue RuleNotFound
          end
        else
          self.get(value)
        end
      end
    end
    if type == :key
      keys[value] = result
    else
      params << result
    end
  end

  if keys.empty?
    block.call(*params)
  else
    block.call(*params, keys)
  end
end