edmundsmith

Method for Emulating Higher-Kinded Types in Rust

Intro

I've been fiddling about with an idea lately, looking at how higher-kinded types can be represented in such a way that we can reason with them in Rust here and now, without having to wait a couple years for what would be a significant change to the language and compiler.

There have been multiple discussions on introducing higher-ranked polymorphism into Rust, using Haskell-style Higher-Kinded Types (HKTs) or Scala-looking Generalised Associated Types (GATs). The benefit of higher-ranked polymorphism is to allow higher-level, richer abstractions and pattern expression than just the rank-1 polymorphism we have today.

As an example, currently we can express this type:

ErnWong

Same as V1 except we do complete redraws instead of using the color-use linked list. Simplifies the pipeline and code significantly.

Host Memory Write       ________       Host Memory Read
       |              _|______  |             ^
 write |            _|______  | |             | read
 logic |          _|______  | |_|             | logic
       `-------->|        | |_|   ------------`
                 | Planes |_|                                                   ^   PLOT: Calculates 4 bit / 8 bit color data
                 |________|                                                     |   from planes and plots them at the correct
              256KiB       |                                                    |   pixel address. Full replots are rare, and

copy

FROM i386/alpine:latest

# https://wiki.gentoo.org/wiki/OpenRC/Baselayout_1_to_2_migration#Boot_runlevel
# https://wiki.alpinelinux.org/wiki/Installing_Alpine_Linux_in_a_chroot#Entering_your_chroot

RUN apk update && \
    apk upgrade && \
    apk add --no-cache linux-vanilla vim openrc && \
    rc-update add devfs sysinit && \
    rc-update add root boot && \

binji

Custom sections in the text format

This page describes a proposal for representing custom sections in the text format.

Rationale

Currently it is impossible to round-trip a WebAssembly module between the binary and text formats without loss of information because there is no way to

Benjamin-Dobell

static jmp_buf jmpEnv;

enum {
    kPrepareBinaryAddress = 0x44dd,
    kMutexBinaryAddress = 0x9090
};

void signal_handler(int n, siginfo_t *info, void *context)
{
    longjmp(jmpEnv, 1);

erikroyall

1.1 Practical Programming - An Introduction to Computer Science Using Python 3
1.2 K&R C
1.3 The C++ Programming Language - Bjarne Stroustrup
1.4 Deitel's Java - How to Program
1.5.1 The Little Schemer
1.5.2 The Reasoned Schemer
1.5.3 The Seasoned Schemer
2.1 Computer Organization and Design - Patterson & Hennessy
3.1 Introduction to Algorithms - Cormen
3.2 Algorithms - Sedgewick

rauchg

require-from-twitter

Since Twitter doesn't have an edit button, it's a suitable host for JavaScript modules.

How to use

Source tweet: https://twitter.com/rauchg/status/712799807073419264

const leftPad = await requireFromTwitter('712799807073419264');

paragonie-scott

Hello software developers,

Please check your code to ensure you're not making one of the following mistakes related to cryptography.

I. General Mistakes

• Writing your own home-grown cryptography primitives (For example: Mifare Classic)
  • Exception: For the sake of learning, but don't deploy it in production.
• Using a fast hash function (e.g. MD5, SHA256) for storing passwords. Use bcrypt instead.
• Not using a cryptographically secure random number generator

DmitrySoshnikov

@kangax's ES6 quiz, explained

@kangax created a new interesting quiz, this time devoted to ES6 (aka ES2015). I found this quiz very interesting and quite hard (made myself 3 mistakes on first pass).

Here we go with the explanations:

Question 1:

(function(x, f = () => x) {

paulirish

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

• elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent