Season#to_s, Colour#to_s

[igneus]

This is something worth a discussion before it gets implemented:

Season and Colour currently lack proper implementation of #to_s and the defaults are rather unsatisfying, e.g.

#<CalendariumRomanum::Season:0x00000001540e88>

What would be the most convenient (most convenient for a Rubyist) return value? Is Rank#to_s the way to go (return a human-friendly name of the rank translated to the current locale) or should this be changed, too?

[igneus]

Possible return values I can think of:

• make #to_s alias of the current method #name, i.e. return name of the colour/season translated for the current I18n.locale ("red", "rubeus", "červená"; "Lent", "Tempus Quadragesimae", "Doba postní"; implementation of this behaviour is already available in #20 )
• the same, but always in English, regardless of the current locale ("red"; "Lent")
• some rather irb-friendly representation of the objects, similar to the default inherited from Object, but a bit more helpful, e.g. something like "#<CalendariumRomanum::Season LENT>"

[igneus]

Examples of behaviour of #to_s in built-in classes:

• Object: like "#<Object:0x000000024c6ab0>" (this inherited default behaviour is preserved also in Dir, Enumerator, File)
• Class, Modul: returns fully qualified class/module name
• Array, Proc and some others: alias of #inspect
• Exception: depends on presence of message:
  • Exception.new.to_s # => "Exception"
  • Exception.new('hi').to_s # => "hi"
• Date, Time: default text representation like "2017-10-29 14:25:08 +0100" and "2017-10-29"

[igneus]

I realized this is quite a general question of Ruby best practices, so I summarized it in a post to the ruby-lang mailing list and received some helpful feedback.

To the response by Matthew Kerwin we can reply that seasons, colours and ranks are not intended to be directly printed and by their nature they are not "something like String".

I find the rules suggested by Victor Shepelev especially helpful:

1. #to_s should show the content of the object, when relevant (for your case, it is relevant, e.g. Lent should be seen somewhere);
2. For value objects, there is no sense in showing object id.
3. Unless object is kinda string (e.g. will most probably be used in situations like [list, of objects].join(' - ') or something), I prefer to stick to # convention, I am not sure what is most appropriate for your case
4. Finally, #to_s should be short and informative enough to play well in the cases like raise ArgumentError, "Expected numeric, #{object} got"

So, considering all above, it is either #, or (if and only if you 100% sure it will be massively used in text rendering) just "red".