withoutboats

Async Methods II: object safety

(Note: this is posted as a gist because my primary blog host is having some trouble today, and I can't get my blog to deploy. It will be on my blog eventually.)

[Last time][async-methods-i], we introduced the idea of async methods, and talked about how they would be implemented: as a kind of anonymous associated type on the trait that declares the method, which corresponds to a different, anonymous future type for each implementation of that method. Starting this

withoutboats

We don't need a need a new error trait if we just fix std::error::Error

Our great anguish around error handling is the incorrectness of the Error trait. Here's an easy way to solve the problem: fix the error trait. Literally: just change the existing trait so that it is correct.

Step 1: Remove description (DONE)

Description is already being deprecated, with a default method provided. Done and done.

Step 2: Add backtrace (TRIVIAL)

withoutboats

This is a list of potential use cases for something like alternative registries & some analysis of how to solve these use cases.

As context, a registry contains two network service components:

1. The index: a git repository containing metadata about the packages in the registry
2. The crate source: an HTTP server serving the actual package data

Private registry

I want to host my own crates separately from crates.io, to serve to people with appropriate access.

withoutboats

We add a built in attribute for handling pin projection:

struct MyCombinator<F> {
    #[pin_accessor]
    field: F,
}

This generates a method fn field_pin(self: PinMut<'_, Self>) -> PinMut<'_, F>, and also generates these constraints:

withoutboats

Considerations for writing a loop over a Stream as it relates to await syntax.

JavaScript uses this syntax:

for await (elem of stream) {
   // ...
}

withoutboats

/*

Psuedocode from signal:

calculate_key_pair(k):
    E = kB
    A.y = E.y
    A.s = 0
    if E.s == 1:
        a = -k (mod q)