add downcase option to String#camelcase

[jkthorne]

resolves #7709

[ysbaddaden]

Just lower would be enough. Both variants (lower camel case, upper camel case) should be documented, too.

[konovod]

Suggested change

	def camelcase(options : Unicode::CaseOptions = Unicode::CaseOptions::None, lowercase_first_letter = false)
	def camelcase(options : Unicode::CaseOptions = Unicode::CaseOptions::None, *, lowercase_first_letter = false)

to prevent just false as argument, suggested in #7709 (comment)

[vladfaust]

I'd stand for just lower as the argument name. It's clearly understandable that lower in context of camelcase means exactly lower camelcase, which is a common term. No need for a long and explicit name here.

[straight-shoota]

lowercase_first_letter is too long.

I'd suggest one of the following (in order of preference):

• downcase_first
• lower
• lower_first

[jkthorne]

@straight-shoota @ysbaddaden what do you think about downcase as the argument?

[straight-shoota]

I'm okay with this, but I'd prefer to name the argument more explicitly downcase_first.

[vladfaust]

That’s bad. camelcase(downcase: true) is confusing. camelcase(lower: true) is better. And I am for breaking change if needed to move the argument to the first place.

[j8r]

Or lower_first, that's about a bit longer than the current downcase and remove any ambiguity

[straight-shoota]

And I am for breaking change if needed to move the argument to the first place.

No. It should only be usable as a named argument to clearly express the semantics.

[jkthorne]

@straight-shoota CI seems to be failing due to running too long. Is this common for CI and how can I rerun it?

[jkthorne]

@straight-shoota thank you for re-running this.
Can we merge this?

[vladfaust]

That's disturbing.

[jkthorne]

@vladfaust Which part is disturbing?

[ysbaddaden]

I'm late to the party, but where the hell did downcase came from? Downcase camelcase doesn't mean anything, it's just confusing.

This is lower or upper camelcase (which affects the first letter) not downcase —a completely different method and meaning 😕

[straight-shoota]

@ysbaddaden It downcases the first character, the equivalent method is #downcase not #lower, so it makes some sense. As mentioned, I'd have prefered downcase_first or lower_first.

[straight-shoota]

Hm, actually, it doesn't even downcase the first character when it's uppercase: "Foo".camelcase(downcase: true) => "Foo". I think this behaviour should be changed to return "foo".

[asterite]

I think the API is fine, the above is just a bug in this PR's implementation.

[wooster0]

Isn't this method generally behaving incorrectly? This method returns "EiffelTower" for "eiffel_tower" but that's wrong. "EiffelTower" is PascalCase, not camelCase. The first letter should be lowercase by default. I think there should be another method, pascalcase that has the current behavior of camelcase.

[j8r]

@r00ster91 Pascal case was discussed in the related issue, please do not duplicate the discussion in this PR.