RustConf 2016 Travelogue

(Previously on An Algorithmic Lucidity.)


The other weekend, excited to learn more and connect with people about what's going on at the forefront of expressive, performant, data-race-free computing—and eager for a healthy diversion from the last two months of agonizing delirium induced by the world-shattering insight about how everything I've cared about for the past fourteen years turns out to be related in unexpected and terrifying ways that I can't talk about for reasons that I also can't talk about—I took Friday off from my dayjob and caught a Thursday night flight out of SFO to exotic Portland (... I, um, don't travel much) for RustConf!

The conference itself was on Saturday, but Friday featured special training sessions run by members of the Rust core team! I was registered for Niko Matsakis's afternoon session on lifetimes, but I arrived at the venue (the Luxury Collection Nines Hotel) early to get registered (I had never seen socks as conference swag before!) and hang out with folks and get a little bit of coding done: my coolest Rust project so far is a chess engine that I wrote this time last year (feel free to go ahead and give it a Star!) which I wanted the option to show off (Option<ShowOff>) to other conference attendees, but the pretty web application frontend had broken due to a recent bug and my JavaScript build pipeline having rotted. I fixed it just in time for the lifetimes training session to start.

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stable_features_version_lint_before_and_afterI used to look down on posers who submit some contrived one-off trivial patch to a big, famous project like Django or whatever, sheerly for the glamor and ego-gratification of being able to say, "I'm a contributor to Django." I thought that if it wasn't a fix that you needed for your own work and you're not going to be a seriously involved contributor, it's more dignified to only work on your personal projects (which would be more authentic) or some non-super-famous but still widely-used library (which would have more socially-useful unfinished work left).

Then I landed a patch in the Rust compiler.

And it is so ego-gratifying!! But maybe now I have to submit a bunch more patches in order to prove—in order to be—a seriously involved contributor rather than a mere poser??


    let path = Path::new("/proc/meminfo");
    let proc_meminfo = match File::open(path) {
        Ok(f) => f,
        Err(e) => {
            println!("Error: {:?}", e);
            // TODO: be kinder to our friends still under Cupertino's rule
            moral_panic!("couldn't read /proc/meminfo?! It is possible \
                          that you are struggling with an inferior nonfree \
                          operating system forced on you by your masters in \
                          Cupertino or Redmond");

Ideas Have Expirations

One often-overlooked aspect of the crime of not-writing is that the harm isn't just about the things that deserve to be said that you never get around to saying because you don't put in the time and effort. It's also about the things that you can't say anymore even if you suddenly had the will, because the opportunity to say it was bound to a particular time, and trying to recapitulate the thoughts months or years after the fact would be irrelevant, or impossible.

This phenomenon comes in degrees. Start with irrelevance. Often the inadmissibility of tardy words isn't absolute: you could say things late, but the product would be less valuable than if it were timely—especially in a medium like blogging, where the posts being dated and displayed reverse-chronologically creates an expectation that the entries are associated with a particular point in time—at least, that they were written not too long before their publication date, even if the actual content isn't about the ephemera of the day or season. This has contributed to An Algorithmic Lucidity not being as good of a blog as it could be.

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Monthly Favorites, September 2015

Favorite commit message fragment: "it turns out that it's `\d` that matches a digit, whereas, counterintuitively, `d` matches the letter 'd'."

Favorite line of code: a tie, between

    let mut time_radios: Vec<(Commit, mpsc::Receiver<(Option<Commit>, f32)>)> =


        for (previous, new), expected in zip(
                itertools.product(('foo', None), ('bar', None)),
                ("from foo to bar", "from foo", "to bar", "")):

(Though both of these contain at least one internal newline, it's only for PEP 8-like reasons; they're both what we would intuitively call one "logical" line of code.)

Favorite film: My Little Pony: Equestria Girls: Friendship Games. (Poor plotting even by Equestria Girls standards, and it could only have been because of magic that I didn't get semantically satiated on the word magic during the climax. Alternate-Twilight's idiotic decision to withdraw her application to the Everton independent study program in favor of transferring to the Canterlot School of Mediocrity and Friendship in order to be closer to the Humane 5+1 was as predictable as it was disappointing—though I do credit the writers for at least acknowledging the existence of alternatives to school. And what was up with that scene where we're momentarily led to believe that alternate-Spike got switched up with Equestria-Spike in a portal accident, but then it turns out that, no, alternate-Spike just magically learned how to talk? Is it that there was no time in the script to deal with the consequences of swapping sidekicks across worlds, but that Cathy Weseluck's contract guaranteed her a speaking role? Despite being the weakest film in the trilogy (far worse than its brilliant predecessor, My Little Pony: Equestria Girls: Rainbow Rocks), Friendship Games is still a fun watch, and an easy favorite during a month when I didn't see any other feature-length films.)

RustCamp Reminiscences

On Saturday the first, I attended RustCamp, the first conference dedicated to the newish (in development for fiveish years, but having just hit version 1.0.0 this May, with all the stability guarantees that implies under the benevolent iron fist of semantic versioning) programming language Rust!


Why RustCamp? (It's a reasonable rhetorical question with which to begin this paragraph: going to a conference has opportunity costs in time and money; things worth blogging about are occasionally worth justifying—even if no one actually asked me for a justification.) A lot of the answer can be derived from the answer to a more fundamental question, "Why Rust?" And for me, I think a lot of the answer to that has to do with being sick of being a fake programmer living in a fake world that calls itself Python.

Don't get me wrong: Python is a very nice place to live: good weather, booming labor market, located in a good school district, with most of the books you might want already on the shelves of the main library and almost all of the others a mere hold request away. It's idyllic. Almost ... too idyllic, as if the trees and swimming pools and list comprehensions and strip malls are conspiring to hide something from us, to keep us from guessing what lurks in the underworld between the lines, the gears and gremlins feeding and turning in the layers of tools built on tools built on tools that undergird our experience. True, sometimes small imperfections in the underworld manifest themselves as strange happenings that we can't explain. But mostly, we don't worry ourselves about it. Life is simple in Python. We reassure our children that that legends of demon-king Malloc are just stories. Everything is a duck; ducks can have names and can be mutable or immutable. It all just works like you would expect from common sense, at least if you grew up around here.

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const PSEUDO_DIGITS: [char; 7] = ['M', 'D', 'C', 'L', 'X', 'V', 'I'];
const PSEUDO_PLACE_VALUES: [usize; 7] = [1000, 500, 100, 50, 10, 5, 1];

fn integer_to_roman(integer: usize) -> String {
    let mut remaining = integer;
    let mut bildungsroman = String::new();
    // get it?? It sounds like _building Roman_ (numerals), but it's
    // also part of the story about me coming into my own as a
    // programmer by learning a grown-up language
    // XXX
    for ((index, value), &figure) in PSEUDO_PLACE_VALUES.iter()
        let factor = remaining / value;
        remaining = remaining % value;

        if figure == 'M' || factor < 4 {
            for _ in 0..factor {

        // IV, IX, XL, &c.
        let smaller_unit_index = index + 2 - (index % 2);
        if smaller_unit_index < PSEUDO_PLACE_VALUES.len() {
            let smaller_unit_value = PSEUDO_PLACE_VALUES[smaller_unit_index];
            let smaller_unit_figure = PSEUDO_DIGITS[smaller_unit_index];

            if value - remaining <= smaller_unit_value {
                remaining -= (value - smaller_unit_value);


// XXX: old_io is probably facing deprecation if names mean anything
use std::old_io;
use std::collections::HashMap;

fn main() {
    let things_to_ask_about = ["name", "age", "username"];
    let mut collected_information = HashMap::new();
    for askable in things_to_ask_about.iter() {
        println!("What is your {}?", askable);
        let input = old_io::stdin()
            .ok().expect("failure message here");
        // XXX EVIDENCE OF MY IMPENDING DEATH in these moments when I
        // want to scream with the righteous fury of a person who has
        // been genuinely wronged, on the topic of what the fuck is wrong
        // with this bullshit language where you can't even trim a string
        // because "`input` does not live long enough" this and "borrowed
        // value is only valid for the block suffix following statement 1
        // at 21:48" that
        // But what the fuck is wrong with this bullshit language is in
        // the map, not the territory
        // on the balance of available evidence, doesn't it seem more
        // likely that the borrow checker is smarter than you, or that
        // the persons who wrote the borrow checker are smarter than you?
        // and if you can't even follow their work even after several
        // scattered hours of dutifully trying to RTFM, will an
        // increasingly competitive global Economy remain interested in
        // keeping you alive and happy in the decades to come?
        // I am not a person who has been genuinely wronged, just a man
        // not smart enough to know any better
        collected_information.insert(askable, input.trim());

    for (askable, response) in collected_information.iter() {
        println!("You claimed that your {} is {}.", askable, response);