Feature: convert back a `Token<'_>` into a `Cow<'_, str>`

[marmeladema]

Hello and thank you for your crate 👍

I am working on a project in which I have a collection of Cow<'_, str> but I would like to encode some of them. To do this, I need to call Token::new(token) but once I have a Token there is no way for me to retrieve back the Cow to store in the collection.

Another alternative would to provide a standalone fn decode_token(Cow<'_, str>) -> Cow<'_, str> function without going through aToken at all if that's preferable.

I am willing to work on this, I just want to know how you feel about it before I start the implementation.

[asmello]

Hi!

Not sure I follow what you're trying to do. Sounds like you just want Token::decoded? Then you could do Token::new(cow).decoded().

If you want to retrieve the raw, encoded version of the token as a Cow<'_, str>, admittedly we don't currently provide a way to do that. There's Token::encoded, but that only returns a reference, so if you started with an owned string you'd need another allocation there. If that's what you mean we could definitely add it, but it sounds like you want the decoded string instead.

[marmeladema]

No, I really want the encoded value but as a Cow.

[asmello]

Got it! That's perfectly reasonable to add. I could do it later today, but feel free to contribute if you want!

[marmeladema]

Which approach would you prefer, From conversion or standalone function?

[asmello]

We could have both: impl<'a> From<Token<'a>> for Cow<'a, str> and Token::into_encoded. Each may be more convenient dependending on the situation.

EDIT: actually, I take that back. The From conversion is ambiguous whether it produces an encoded or decoded string. Let's keep the intrinsic method only.