String.capitalize() should have a “leave the rest of the word alone” option

[josevalim]

The reason why we do first letter only is because Unicode has specific rules that consider the rest is being lowercased.

For the behaviour that you want, you should be able to implement it using String.next_grapheme, getting the first part, upcasing it an then concatenating the rest. Just make sure to take into account empty strings.

@mikl

(If you come across this topic wanting to just capitalize the first letter, you can use String.Casing.titlecase_once(word, nil) , although this is a little undocumented).

Don’t do this. String.Casing is private API and may change at any time, breaking your code.