call_method_like_proc.rb

module Banana
  # Provides low level support functionalities.
  module Kernel
    # Calls a method with the maximum possible amount of arguments.
    #
    # Ruby's arity telling is too inaccurate so we just try to call the method
    # with everything we have and if this raises an ArgumentError we examine the
    # maximum allowed amount of arguments and pass those.
    #
    # Dont believe me?
    #
    #   ->(a, b = "") {}.arity
    # => -2
    #   ->(a, *b) {}.arity
    # => -2
    #
    # @param [Proc, Lambda, UnboundMethod] method The method object you want to call.
    #                                             This is typically an UnboundMethod but you can pass everything as long as it `respond_to?(:call)`
    # @param args Arbitrary arguments which will passed to `method`
    # @param [Proc] block Optional block which will be passed to `method`
    def __call_method_like_proc method, *args, &block
      sliced = false
      method.call(*args, &block)
    rescue ::ArgumentError => exception
      # examine allowed amount of arguments
      match = exception.message.match(/wrong number of arguments.+\(([0-9]+) for ([0-9]+)\)/)

      if !sliced && match
        if match[2] == "0"
          args = []
        elsif match[2].to_i != 0
          args = args[0...match[2].to_i]
        else
          raise exception
        end
        sliced = true
        retry
      end
      raise exception
    end
    module_function :__call_method_like_proc
  end
end