class Opal::Nodes::Args::Parameters

def initialize(args)
  @args = args.children
end

def on_arg(arg)
  arg_name = arg.meta[:arg_name]
  %{['req', '#{arg_name}']}
end

def on_blockarg(arg)
  arg_name = arg.meta[:arg_name]
  arg_name = :& if arg_name == :fwd_block_arg
  %{['block', '#{arg_name}']}
end

def on_kwarg(arg)
  arg_name = arg.meta[:arg_name]
  %{['keyreq', '#{arg_name}']}
end

def on_kwnilarg(_arg)
  %{['nokey']}
end

def on_kwoptarg(arg)
  arg_name = arg.meta[:arg_name]
  %{['key', '#{arg_name}']}
end

def on_kwrestarg(arg)
  arg_name = arg.meta[:arg_name]
  if arg_name
    %{['keyrest', '#{arg_name}']}
  else
    %{['keyrest']}
  end
end

def on_mlhs(_arg)
  %{['req']}
end

def on_optarg(arg)
  arg_name = arg.meta[:arg_name]
  %{['opt', '#{arg_name}']}
end

def on_restarg(arg)
  arg_name = arg.meta[:arg_name]
  if arg_name
    arg_name = :* if arg_name == :fwd_rest_arg
    %{['rest', '#{arg_name}']}
  else
    %{['rest']}
  end
end

def on_shadowarg(_arg); end

def to_code
  stringified_parameters = @args.map do |arg|
    public_send(:"on_#{arg.type}", arg)
  end
  "[#{stringified_parameters.compact.join(', ')}]"
end