Thank you PR.
By the way Capital underscore is a format used in what programming languages?

I've used it from time to time. OCaml guidelines (ironically, given OCaml's name) do something sort of like this, but it's only the first word that is capitalized.

Someone else called it "Cobra Case" here.

Thank you.
I have looked at the reference URL.
On that basis, I have a little doubt.

1. Foo_Bar is not capital underscore. Is not it cobra case ?
   Searching for capital underscore will find https://github.com/s-hiroshi/development-guide-public/blob/master/coding-guide/README.md
   FOO_BAR format is called capital underscore. It is likely to get confused.

2. Are you programmers using OCaml?
   If so, there is no use for the Foo_Bar format. Do you need the Foo_bar format?

3. What is the name of Ocaml's Foo_bar format?

I have programmed in OCaml occasionally but I don't know what they call that sort of format. Maybe it should be called "Objective_case?"

I remember seeing some C++ code that used this "Cap_Underscore" style a few years ago for types but I don't remember where it was. Since then I have liked to use it for personal projects. If you don't think it's popular enough to warrant an addition (as I myself had difficulty looking this type of style up online) to this package feel free to close this.

understood. You want to use it on a personal project.
Let's add capital underscore style if you need it.
Since string-inflection itself was originally for yourself, I would like to add a conversion rule if there is demand for even one person.

We fixed it because there was a part which did not fit a little with master's latest.
So please try using master's latest.

Thank you!