Accordion of Literal types

accordion_of_types.rb

# Okay
class Foo < Literal::Data
  attribute :sizes, Array
end

# Better
class Foo < Literal::Data
  attribute :sizes, Array(Symbol)
end

# Even better
class Foo < Literal::Data
  attribute :sizes, _Array(
    _Union(:sm, :md, :lg, :xl)
  )
end

# Much better
class Foo < Literal::Data
  Size = _Union(:sm, :md, :lg, :xl)
  
  attribute :sizes, _Array(Size)
end

# Very good
class Foo < Literal::Data
  class Size < Literal::Enum(Symbol)
    SM(:sm)
    MD(:md)
    LG(:lg)
    XL(:xl)
  end
  
  attribute :sizes, _Array(Size)
end

# Best
class Foo < Literal::Data
  class Size < Literal::Enum(Symbol)
    SM(:sm)
    MD(:md)
    LG(:lg)
    XL(:xl)
  end
  
  attribute :sizes, Literal::Array(Size)
end