rand VS rust

Making compatibility promises for distributions means they cannot take advantage of potential advancements in the field.

Defining an error type that is meaningful, portable, and compatible with no-std isn't straightforward. If the std lib's getrandom requires std, then just like that, rand and many other crates won't use it anyway. Using io::Result seems to me to face this challenge.

Some wasm targets can’t generate random numbers at all but in the case of the book because you are using wasm in a browser you can use JS to generate random numbers. I believe there’s a way to get the rand crate to use JS as the backend for generating rand but its a bit more convoluted than the easy one-liner that the book suggests.

rand

This uses rand and xcomplex to handle the mathematics, png to write image files, and dialoguer and indicatif for some pretty prompts and progress bars.

You can often achieve this without any unsafe by putting an assert!() on the length before the hot loop. For example, I got rid of some unsafe in rand that way.

This is a widely used method to map random integers to floating point numbers, but it has the disadvantage of wasting 1 bit of float mantissa precision.

On modern CPUs, its computational advantage over full-precision mapping methods, such as multiplication by a float, is not always clear [1].

[1] https://github.com/rust-random/rand/issues/416

In fact, there are a lot of crates in Rust where in other programming languages, it would be included in the standard library. Examples are regex, random number generators, additional iterator methods, macros for other collections, num traits, loggers, HTTP libraries, error handling, async runtimes, serialization and deserialization, date and time, and many more.

The esp-template issue might be this one: https://github.com/esp-rs/rust/issues/158. Try with --release or updating to 1.68.0 with espup update. I'll take a look at the log as soon as I can, atm Im on the phone and is not that easy to scroll through :(

Sure. Espressif maintains a fork which adds support for their microcontrollers.

I am trying to make a vaccine passport validation for my country using the ESP32 for my micro controller. I have gotten the std rust library to compile using (esp-rs)[https://github.com/esp-rs/rust], but the actual validation library that I use needs openssl which refuses to compile.

Xtensa. They've got a fork of LLVM that supports it that they're working toward getting upstreamed. The community has a fork of rustc that uses it (and a quickstart crate) while we wait for it to get upstreamed.

It only works if you have an Xtensa compiler which takes hours to compile, here: Rust Xtensa (if you don't have it). The network driver is just a function that sets the name of the driver so the Esp32 does something other that blinking.