chacha etc. documentation?

[rukai]

On this page the links to chacha and hc128 does not point to an actual page: https://docs.rs/rand/0.6.0/rand/rngs/struct.StdRng.html

Also https://rust-random.github.io/book/guide-rngs.html this page mentions chacha and other rngs and seems to imply they are in the rngs module, but I cant find it there or anywhere else.

[dhardy]

Sorry, they moved:

• https://crates.io/crates/rand_chacha
• https://crates.io/crates/rand_hc

[rukai]

Ok, so if I understand this correctly.
Because StdRng claims "Reproducibility of output from this generator is however not required"
I need both the rand crate and a secondary crate e.g. rand_chacha in order to ensure the same seed will always generate the same sequence of random numbers?

[dhardy]

If you want reproducibility, use (for example) ChaChaRng, which is provided by rand_chacha. Don't use StdRng because we reserve the right to change the algorithm in the future.

[rukai]

Ah, my bad, it wasnt clear what the point of my question was.
It looks like I need to include two crates in my Cargo.toml in order to use chacha. rand and rand_chacha. Is this correct?

[dhardy]

Yes, you need both.

[dhardy]

My mistake with the link; I've used relative links from the book but should probably only use absolute links from the API docs because they can be hosted on a different site (currently these links work from here but not docs.rs).

• Fix relative links from API to book found by rg "\.\./rand_"
• Mention where to find other RNGs in the guide

[dhardy]

The broken relative links are to other Rand project crates, not to the book. I'd prefer not to use absolute links everywhere.

@vks @burdges @newpavlov should we just make https://rust-random.github.io/rand/ the official API documentation, and not link to docs.rs? Maybe even add a note at the top stating that this is intended to be read from that URL (or a local build)?

[newpavlov]

Personally I prefer to use docs.rs for documentation in my projects. Also when I explore a crates I often simply type docs.rs/<crate_name> into browser.

[dhardy]

If the docs.rs folks would fix this issue I'd be happy to go back to that as the primary source of documentation — it does have advantages, such as always being true to the current release version instead of the master branch.