Add various encoding crates

[FeldrinH]

One fairly common usecase that doesn't seem to be covered by crates on blessed.rs is encoding text and binary data.
In particular I think there are two main cases:

• Encoding strings with a non-UTF8 encoding
  • UTF8 encoding is well supported by the standard library, but for other encodings you need an external library. The main choice for this seems to be encoding_rs.
• Encoding binary data to string. In particular the two common cases here are hex and base64.
  • For hex there is the crate hex. This crate hasn't had a release in 2 years and there are a number of unmerged pull requests. I don't know if this is a cause for concern or not.
  • For base64 there is base64.
  • Another popular one seems to be data-encoding, which supports hex, base64 and a few other encodings.

It would be nice if at least some more stable and well maintained encoding crates could be added to blessed.rs, especially since encoding is an area where both performance and correctness are important, so you would want to prefer crates that have been vetted by the community.

[djc]

I agree that all of these are popular and thus deserving of a mention. I'm personally not a fan of recent developments in the API of the base64 crate (and I know I'm not the only one), so maybe its mention should be qualified somehow.

[FeldrinH]

I'm personally not a fan of recent developments in the API of the base64 crate (and I know I'm not the only one), so maybe its mention should be qualified somehow.

I hadn't heard of this. I presume you are referring to either marshallpierce/rust-base64#205 or marshallpierce/rust-base64#213 or maybe both.

[djc]

The former in particular, and IIRC there were more issues raised after that.

[BurntSushi]

If encoding_rs is included, please be sure to mention that its scope is fairly strictly restricted to the WHATWG Encoding Standard, which is focused on the web. (And this is totally fine, but some folks might find some holes in the library surprising if they don't know about its scope.)

[paulgb]

+1 for data_encoding over base64. It supports base64 and has a cleaner API.

[FeldrinH]

If encoding_rs is included, please be sure to mention that its scope is fairly strictly restricted to the WHATWG Encoding Standard, which is focused on the web. (And this is totally fine, but some folks might find some holes in the library surprising if they don't know about its scope.)

On that note: Is there a viable alternative for encoding_rs if you need text encodings not included under the WHATWG standard? I couldn't find anything with a few quick google searches.