Solarsail

Not the GP, but I recall the KeePass password manager using xdotool for its autotype feature. I struggled to get xdotool to work correctly back in 2014 on a Debian 7 personal computer. Not familiar with 'x2x' or 'xev'

Don't agree -w/all this cynicism... (Did I get a programmer's joke to work?)

Your fastest open-cycle resource usage is water. If you can recycle your water, you've got much slower mass-growth per unit of time in free flight. This could make the difference between 8 hour spacewalk capabilities and 8 day spacewalks.

I've wanted to do this myself... Tho as both an armchair engineer and an armchair programmer. If I'd gotten through engineering in university, (and studied programming language design) this would be an utterly tempting idea for me to try. I must have come back to thinking about doing this ten times in the last fifteen years or so. Off the top of my head, scientific models also sound like they might fit with constraint modelling, tho I might be far too superficial in my understanding of both subjects there.

Now I'm inspired to try to fill out this list...

Pegasus (company's first try overall), Antares, all of the Minotaurs, Atlas 3 and 5 might count as new... Epsilon, H-2 (new?), Vega, Ariane 1, 3 & 4... And the Ariane 1 is both totally new on a systems level and an institution's first attempt at building one. Long March 5, 6 & 7.

Of the investor-backed launch startups, I think it's either no company got it first try... or Orbital Sciences counts as making it first try with Pegasus. Not sure if they count as an investor backed startup.

You could probably get even better walk-able integration by connecting together multiple floors worth of hallways, one above the other. That could approach a 3D city a little bit more.

Isn't it rather precedented to do this? In most readings (that I've seen, anecdotally) of Timothy McVeigh's writings, or Hitler's Mein Kamph, people read these works specifically in the framing of a path to the atrocities, rather than in erstwhile debate of normative claims.

Twitter has a mostly negative ROI for me; I wind up having mild panic attacks both when I visit it, and when I'm reminded of it in the rest of my day.

Almost any reminder that people are having conversations there (especially politics / social commentary)... or forming thought about the world there, makes me fear humanity.

Basically I just keep it around since some (like here on HN) think that it's valuable to prove you exist using an established account.

Speaking of which, how learnable is Elm without any HTML familiarity? I more or less gave up on learning it once the (previous) Elm book started piecing together HTML tags in Elm syntax...

(Apologies if this is too much a personal anecdote for HN) Honestly, this is one of the indicators that forces my distrust of the modern family of social discourse. My own suspicions have a specific conversation in 2012 spooking a few hundred people (online), who lashed out with such odd phrasing that it spread contagiously to whoever they met... And formed the chimera movement we see now.

...I might outright have an alternate history of the entire '10s "Culture War". Or I might have gone paranoid. Of course I can't prove any of it. I'd love an answer to your first question myself.

Similar issue applies on Windows with Visual Studio's C# compiler; Tho in that case it's a terminal with a non-default starting script that adds the C# compiler, so default and that non-default terminal point CSI or CSC at different languages.

Sounds like the errors I got installing spacemacs. I think... I forced it to work by changing the access permissions on a folder that spacemacs itself had created.

Well, the tutorial itself has received translations from m68k Turbo Pascal to x86 C : https://github.com/lotabout/Let-s-build-a-compiler

While it wouldn't support fuel use akin to fuel burning electrical sources on Earth, there are endothermic methods to pull molecular oxygen out of C02. In addition to the water electrolysis already mentioned, C02 can be partially reduced to carbon monoxide with artificial photocatalytic systems, or solid oxide electrolysis (with electrical input instead of solar input). Electrolysis would be counterproductive for primary energy, but rocketry only needs stored energy rather than primary. Otherwise, plants doing photosynthesis in a greenhouse could use C02 from outside the greenhouse. Photosynthetic production of oxygen would have side effects of useful agriculture, but that would be difficult to set up early in a Mars settlement effort.

http://wren.io/ Has been around HN before, as has https://fascinatedbox.github.io/lily/

Were either of these two the ones you were thinking of?

The word hypergolic doesn't mean that, but in spaceflight the term refers to a fairly specific group of compounds; Dinitrogen tetroxide and unsymmetrical dimethylhydrazine or monomethylhydrazine (UDMH / MMH).

Just a couple of asides, since I was reading about these very subjects (Am-241 RTGs and outer solar system photovoltaics) a few weeks ago;

The UK's NNL prototyped out a process for volume manufacture of Am-241 in 2013. http://www.nnl.co.uk/news-media-centre/news-archive/space-ba... And a few notes about the Americium-RTG effort more generally: http://www.planetary.org/blogs/guest-blogs/2015/0423-can-a-n...

NASA has also studied use of solar power beyond Jupiter's orbit: (PDF link) https://www.lpi.usra.edu/opag/nov_2007_meeting/presentations...

(Edit: Fixed a link)

As an aside, when I played that game I once made an octal data tape, capable of reading 3 bits of state from a single block in the tape (the "loop"). Used three read circuits next to the tape, which allowed it to detect an additional three states; Namely the block could be non conductor, simple conductor, or a piston block facing up / sideways / down. From there, timing data is enough to distinguish a "sticky piston" from a regular one, allowing for 8 different states distinguishable to the read head.

(Apologies if this is me-too ism)

Well, there is Shen. Static typing, I think it can do dependent typing... Doesn't have the affine types of Rust tho. Not sure how it works out to use in practice.

Discussed here, for example: https://news.ycombinator.com/item?id=9297665

Disclaimer: Going off memory of the presentations myself, not at all an expert, etc.

Ivan Goddard's descriptions of the branch predictor sounds quite simple that I can remember; The predictor itself is completely detached from the compiler, outside of the instruction layout falling into EBBs. A point that (I think is on the Mill forum somewhere) they've said about the prediction algorithim itself, is that they're doing simulations with nearly the simplest known prediction algorithm, and getting something like 90% success rates from that compared to the 98% the state-of-the-art sees. The difference is entirely in what data is carried by the prediction. (I believe this is in the forum thread on Switch statements, referenced in this video) What the predictor stores and delivers as output is the logical equivalent to an instruction pointer, and where in the EBB they exit, instead of a boolean (or an entire exit table). Which is more state, but not replacing the entire state of the processor. And, as explained in this presentation, the impact of having (effectively) an instruction pointer from the branch predictor is you know what to prefetch from memory. And that pointer, being associated with some other EBB that the predictor might know about, is also enough to ask the predictor for the next prediction, get a second prefetch, and so on.

That also has implications to a point Goddard made in this presentation, in that some entire Switch statements have only one "EBB" (although that's loose terminology itself), and thus only one prediction associated with it. The prediction is to where the block will exit, not whether any specific prediction will succeed, thus there is no case where the processor will stall multiple times before finding the correct control flow. It can only fail once before it determines the correct exit to the block (in general, at least...)

Which is I believe how they are expecting good results, rather than anything peculiar about how they determine the prediction from history.

With the disclaimer that I don't fully understand Gamergate myself, and the following account sounds possibly incomplete, it seems like a workable summary of part of the subject. https://www.reddit.com/r/explainlikeimfive/comments/2g9tit/e...

Edit: I suppose I could note, some of the Youtube personalities who (I have heard) supported the movement are currently staunchly anti-feminist. I'm not certain how central they were to the movement at the time, but they may be relevant to the comments others have made involving the impact of the group.

Well, for what it's worth, that is an impressive looking game from a solo developer. Looks better than a number of (enjoyable) games by small teams I can think of. Tho I suppose that's a small solace, against the low sales numbers.

While I do agree that the case highlighted shows a rather uncharitable reaction to said personal anecdote, I suspect your advice could be turned around itself in a number of circumstances. Live and let live. Somebody tells a personal story with a somewhat-incomplete perspective? Live and let live. Some stranger on the internet paints the sky as falling because of said anecdote being shared? Live and let live. Both acts remind me of the old 'someone's wrong on the internet' XKCD comic.

I'm a bit curious about combining RAII or similar with dynamic types myself. It's been discussed at mild length here: https://news.ycombinator.com/item?id=9356925

If we assume some sort of object orientation, or first class functions are available, affine types become (I think) impossible; If a value T with lifetime 'a is handed to a completely unknown method on an unknown object, or to an arbitrary lambda, we can't prove that the method will not destroy T in the middle of lifetime 'a. In otherwords, if typechecking is ruled out, we cannot do borrowchecking either.

Well, I've used an unmaintained almost-vanilla-Java REPL: https://github.com/jacktasia/java-repl

Well, there's a couple of pieces of sample code on comp.arch in google groups / usenet. Sadly, I can't find any examples of genAsm anywhere, but a couple of fragments of conAsm. Maybe that's better, as conAsm is what's going to actually run.

This tread for example, talks about instruction density of Mill programs. Mill does somewhat poorly, with a pre-alpha quality compiler doing the codegen; https://groups.google.com/forum/#!topic/comp.arch/RY3Bk7O61u...

Comparing several ISAs on the simple program in the first post, a Mill Gold CPU binary weighs in at 337 bytes (and 33 instructions), compared to:

* powerpc: 212 bytes, 53 instructions * aarch64: 204 bytes, 51 instructions * arm: 176 bytes, 44 instructions * x86_64: 135 bytes, 49 instructions * i386: 130 bytes, 55 instructions * thumb2: 120 bytes, 51 instructions * thumb: 112 bytes, 56 instructions

Well, scriptcs sounds somewhat analogous. Similar REPL for C#, allows for packaged scripts, plays nicer with the filesystem than an IDE (which you'd expect for command-line apps). http://scriptcs.net/

Note: I've tried to use scriptcs, but the extent of my C# knowledge consists of pretending it's Java. But people do seem to compare it to LINQPad, so maybe it fits.

Not the GP, but referring to the more broad anti-PC movement... Lets say The War On (the war on) Christmas. Fear of being PC in a context like that may work out as somebody avoiding the term "Hanukkah", even while speaking about / to a Jewish person, for fear of papering over Christmas, or looking like they're trying to change the name of the holiday.

Some other anti-PC things, like use of the term "black people" in preference to "people of color" or "african-americans"; Or describing men and women in drastically different terms, or painting them as inevitably vastly different (to avoid papering over the differences or making them look non-existent) are their own kind of cultural sensitivity. Or in some cases, even a similar sort of language policing that has long been attributed to political-correctness, just on avoiding terms that people view as originating from it.

Just replicated this bug in Firefox, IE and Edge. Can't find a way to debug the problem, tho.

Brainfuck. That particular computer... Was an 8 instruction machine with a... very short data tape. It could increment / decrement numbers on the tape, move back and forth on the tape, use loop constructs to select instructions, and print / read numbers from a panel. Was far too diminutive to run anything of interest, but it did technically have all 8 instructions.

As it happens, there've been a bunch over the years. Including a hardware implementation of BF, I think a stack machine at one point... At least one that was pipelined, and since I largely stopped following the scene, a bunch built using command blocks. (Tho that's a bit cheaty if you're looking to understand how they're built instead of just the instruction set.)

I tried building a compiler for one particular computer, the RedGame 2. Which in practice meant an assembler + installer, lol. Somebody else also built an emulator and the other assembler for that computer. Also remember Ohm's computer, a 16-bit machine which was... practically vertical. There were lanes for 16 bits side by side, all of the ALU functions were stacked one above the other, and all of the registers were likewise stacked beside the ALU. It also had an assembler, and an emulator (in Bash, IIRC).

Among the interesting / odd things about Redstone computers, is just how slow signals propagate down wires compared to the gate speed. By in large, small is the only form of speed. That, and small is kindof necessary, via the sheer space constraints imposed by being inside a game. The one 64 bit ALU I saw once... was sufficiently wide that you had to stand close to the middle to keep the entire thing in simulation range. Corollary to that, is the low speeds can make the operation of the chip substantially intuitive. With the RedGame 2, a few times I would try to follow ROM reads, instruction decode, register reads, ALU ops, and right back to the condition in time to select the next instruction. That was a bit of an oddity of the RedGame, every instruction contained a conditional branch. You would use... 2 or 3 bits as an operand for what condition to check, list out two (!) instruction numbers to branch to on true/false.

I've (much more) recently mulled over building my own CPU, tho it'd be a couple months worth of work. Most recent sketch was of something of a Mill-alike. It'd be an 8-bit, with 8 belt positions, one ALU, 12 bit instructions with ~30 ops available, and maybe 128 program instructions in ROM. Not sure I could actually fit any RAM, tho... With RAM being positively huge, and any mildly compact part-analog storage taking around 5-10 seconds per read. I'm also not sure something so small it can only fit one ALU really benefits from a belt architecture, rather than a 3-operand register machine. For that matter, most Redstone computers use quite wide program ROMs instead of a Von Neumann architecture, so instruction bits are practically the cheapest part of these computers.

Not sure if that's more informative than making a more-capable ISA and writing an emulator in C.