Method Inference

method.rb

class MethodDefinition
  def infer(typer)
    forced_type = @return_type
    inferred_type = @body.infer(typer)
    actual_type = if forced_type.nil?
      inferred_type
    else
      forced_type
    end

    if !actual_type.is_parent(inferred_type)
      raise "inference error"
    end
    return actual_type
  end
end