All Posts

Units of Measure in Rust with Refinement Types

Years ago, Andrew Kennedy published a foundational paper about a type checker for units of measure, and later implemented it for F#. To this day, F# is the only mainstream programming language which provides first class support to make sure that you will not accidentally confuse meters and feet, euros and dollars, but that you can still convert between watts·hours and joules. I decided to see whether this could be implemented in and for Rust. The answer is not only yes, but it was fun :)

Layoff survival guide

If you’re reading these lines, you may have recently been laid off from your job. Or maybe, depending on your country and its laws, you’re waiting to know if you’re being laid off. Well, I’ve been there and I’ve survived it, so, based on my experience, here are a few suggestions:

The BinAST diaries - Compression, part 1

If you have been following the work on the JavaScript Binary AST, you probably realized that we haven’t been communicating much recently. Sorry about that, we’ve been busy iterating on it! In this blog entry, I’d like to talk to you about our current main focus: file compression.

New blog: Space·Time Will Tell

New blog: Space·Time Will Tell

I have decided to keep this blog for professional use and move everything related to storytelling, role-playing games or improv acting to a new location. Without further ado, let me introduce Space·Time Will Tell! At the menu: a comic book tutorial for Fate RPG! using Tarot-like cards for storytelling! several elevator pitches for stories I haven’t had the time to write! the Space·Time Deck! the Ronin Time Bureaucrats! adventure and excitement!

And now, for something completely different: Ronin Time Bureaucrats

When I’m not busy attempting to reduce the startup time and power requirements of web pages with the JavaScript Binary AST, I’m into Improv Acting and Role-Playing Games. I’d like to introduce a hobby project of mine, which I have started over the summer: Ronin Time Bureaucrats – an narrative/improv Role-Playing Game of Handwavy Time Paradoxes.

Thinkerbell Postmortem/Brain dump

Two years ago, I was working on a research project called “Project Link” as part of the Connected Devices branch of Mozilla. While this branch has since been stopped, some part of Project Link lives on as Project Things. One of the parts of Project Link that hasn’t made it to Project Things (so far) was Thinkerbell: a Domain-Specific Language designed to let users program their SmartHome without coding. While only parts of Thinkerbell were ever implemented, they were sufficient to write programs such as: Whenever I press any button labelled “light” in the living room, toggle all the lights in the living room. or If the entry door is locked and the motion detector notices motion, send an alarm to my SmartPhone. Thinkerbell also had: semantics that ensured that scripts could continue/resume running unmonitored even when hardware was replaced/upgraded/moved around the house, including both the server and the sensors; a visual syntax, rather than a text syntax; a novel type system designed to avoid physical accidents; a semantics based on process algebras. Ideally, I’d like to take the time to write a research paper on Thinkerbell, but realistically, there is very little chance that I’ll find that time. So, rather than letting these ideas die in some corner of my brain, here is a post-mortem for Thinkerbell, in the hope that someone, somewhere, will pick some of the stuff and gives it a second life. Note that some of the ideas exposed here were never actually implemented. Project Link was cancelled while Thinkerbell was still in its infancy.

HolyJIT: Could we write a multi-staged JIT compiler?

Credit While I’m the author of this blog post, 99% of the work was done by Nicolas B. Pierron. So far, my role in this project has largely been to play the wise old advisor, nodding and smiling mischeviously whenever Nicolas started exploring new ideas, and emitting cryptic comments in Reverse Jedi Notation. A few months ago, we published a short (and mysterious) blog post in which we mentioned HolyJIT, an early research project towards a novel approach to writing JITs. In this blog post, I would like to detail a bit more the ideas behind HolyJIT.

JavaScript Binary AST diaries - How to replace proving with validating for fun and profit

In this entry, I’d like to discuss one of the most interesting and unusual aspects of the Binary AST: how we gain performance by turning proof-building into validation, and why this is very good news for performance (and maybe not so good news for file size).

Typestates in Rust

A long time ago, the Rust language was a language with typestate. Officially, typestates were dropped long before Rust 1.0. In this entry, I’ll get you in on the worst kept secret of the Rust community: Rust still has typestates.

Binary AST - Motivations and Design Decisions - Part 1

“The key to making programs fast is to make them do practically nothing.” - Mike Haertel, creator of GNU Grep. Binary AST - “Binary Abstract Syntax Tree” - is Mozilla’s proposal for specifying a binary-encoded syntax for JS with the intent of allowing browsers and other JS-executing environments to parse and load code as much as 80% faster than standard minified JS. It has recently cleared Stage 1 of the TC39 standards process, and while the final byte-level format isn’t completely nailed down, we’re confident that the final implementation will deliver the impressive performance improvements promised by the prototype.