https://www.reddit.com/r/RedditDayOf/comments/7we430/donald_...
https://www.reddit.com/r/RedditDayOf/comments/7we430/donald_...
> [Donald Knuth] firmly believes that having an unchanged system that will produce the same output now and in the future is more important than introducing new features
This is such a breath of fresh air in a world where everything is considered obsolete after like 3 years. Our industry has a disease, an insatiable hunger for newness over completeness or correctness.
There's no reason we can't be writing code that lasts 100 years. Code is just math. Imagine having this attitude with math: "LOL loser you still use polynomials!? Weren't those invented like thousands of years ago? LOL dude get with the times, everyone uses Equately for their equations now. It was made by 3 interns at Facebook, so it's pretty much the new hotness." No, I don't think I will use "Equately", I think I'll stick to the tried-and-true idea that has been around for 3000 years.
Forget new versions of everything all the time. The people who can write code that doesn't need to change might be the only people who are really contributing to this industry.
In theory, yes. In practice, no, because code is not just math, it's math written in a language with an implementation designed to target specific computing hardware, and computing hardware keeps changing. You could have the complete source code of software written 70 years ago, and at best you would need to write new code to emulate the hardware, and at worst you're SOL.
Software will only stop rotting when hardware stops changing, forever. Programs that refuse to update to take advantage of new hardware are killed by programs that do.
The real reason for software churn isn't hardware churn, but hardware expansion. It's well known that software expands to use all available hardware resources (or even more, according to Wirth's law).
So pretty much none of the peripherals--including things like system memory and disk drives, do note--from a computer in 1995 can talk using any of the protocols a modern computer supports (save maybe a mouse and keyboard) and require compatibility adapters to connect, while also pretty much none of the software works without going through custom compatibility layers. And based on my experience trying to get a 31-year old Win16 application running on a modern computer, those compatibility layers have some issues.
"SATA" stands for "serial ATA", and has the same basic command set as the PATA from 1984 - bridge chips were widely used. And it all uses SCSI, which is also what USB Mass Storage Devices use. Or if you're feeling fancy, there's a whole SCSI-to-NVMe translation standard as well.
HDMI is fully compatible with single-land DVI-D, you can find passive adapters for a few bucks.
There's one port you forgot to mention: ethernet! A brand-new 10Gbps NIC will happily talk with an ancient 10Mbps NIC.
It might look different, but the pc world is filled with ancient technology remnants, and you can build some absolutely cursed adapter stacks. If anything, the limiting factor is Windows driver support.
The basic peripherals (keyboard and monitor) of today still present the same interface as they did back in the IBM PC era. Everything else is due to massive hardware expansion, not hardware churn.
How often do you update your drivers compare to your typical internet connected app? Software that handles the idiosyncrasies of the hardware (aka drivers) generally has a much longer lifespan than most other software; I don't see how you can reasonably say hardware breaking backwards compatibility is why software keeps changing.
We rewrite stuff for lots of reasons, but virtualization makes it easy enough to take our platforms with us even as hardware changes.
It doesn't matter if x86 is backwards compatible if everything else has changed.
No code can last 100 years in any environment with change. That's the point.
The amazing backwards compatibility of Windows is purely due to the sheer continuous effort of Microsoft.
I never said it did; other ISAs have similar if not longer periods of backwards compatability (IBM's Z systems architecture is backwards compatible with the System/360 released in 1964).
> The amazing backwards compatibility of Windows is purely due to the sheer continuous effort of Microsoft.
I never mentioned Windows but it's ridiculous to imply its backwards compatability is all on Microsoft. Show me a single example of a backwards breaking change in x86 that Windows has to compensate for to maintain backwards compatability.
I never said that. Windows was just an easy example.
>Show me a single example of a backwards breaking change in x86 that Windows has to compensate for to maintain backwards compatability.
- The shift from 16-bit to 32-bit protected mode with the Intel 80386 processor that fundamentally altered how the processor managed memory.
- Intel 80286 introduced a 24-bit address bus to support more memory, but this broke the address wraparound behavior of the 8086.
- The shift to x86-64 that Microsoft had to compensate with emulation and WOW64
Any many more. That you think otherwise just shows all the effort that has been done.
I said x86 has "over 30 years of backwards compatibility". The 80386 was released in 1985, 40 years ago :)
> Intel 80286 introduced a 24-bit address bus to support more memory, but this broke the address wraparound behavior of the 8086.
This is the only breaking change in x86 that I'm aware of and it's a rather light one as it only affected programs relying on an exactly 2^16 memory space. And, again, that was over 40 years ago!
> The shift to x86-64 that Microsoft had to compensate with emulation and WOW64
No, I don't think so. A x86-64 CPU starts in 32 bit mode and then has to enter 64 bit mode (I'd know, I spent many weekends getting that transition right for my toy OS). This 32 bit mode is absolutely backwards compatible AFAIK.
WOW64 is merely a part of Microsoft's OS design to allow 32 bit programs to do syscalls to a 64 bit kernel, as I understand it.
The backward-compat story is also oversold because, yes, baseline TeX is backward compatible, but I bet <0.1% of "TeX" document don't use some form of LaTeX and use any number of packages... which sometimes break at which point the stability of base TeX doesn't matter for actual users. It certainly helps for LaTeX package maintainers, but that doesn't matter to users.
Don't get me wrong, TeX was absolutely revolutionary and has been used for an insane amount of scientific publishing, but... it's not great code (for modern requirements) by any stretch.
Only if you can't reasonably buy a direct replacement. That might have been a bigger problem in the early days of computing where people spread themselves around, leaving a lot of business failures and thus defunct hardware, but nowadays we all usually settle on common architectures that are very likely to still be around in the distant future due to that mass adoption still providing strong incentive for someone to keep producing it.
You can always run code from any time with emulation, which gives the “math” the inputs it was made to handle.
Here’s a site with a ton of emulators that run in browser. You can accurately emulate some truly ancient stuff.
Arguably modern operating systems are all sort of virtual machine emulators too. They emulate a virtual computer which has special instructions to open files, allocate memory, talk to the keyboard, make TCP connections, create threads and so on. This computer doesn't actually exist - its just "emulated" by the many services provided by modern operating systems. Thats why any windows program can run on any other windows computer, despite the hardware being totally different.
Completely sidestepping any debate about the language design, ease of use, quality of the standard library, size of community, etc... one of its strengths these days is that standard code basically remains functional "indefinitely", since the standard is effectively frozen. Of course, this requires implementation support, but there are lots of actively maintained and even newer options popping up.
And because extensibility is baked into the standard, the language (or its usage) can "evolve" through libraries in a backwards compatible way, at least a little more so than many other languages (e.g. syntax and object system extension; notable example: Coalton).
Of course there are caveats (like true, performant async programming) and it seems to be a fairly polarizing language in both directions; "best thing since sliced bread!" and "how massively overrated and annoying to use!". But it seems to fit your description decently at least among the software I use or know of.
While writing "timeless" code is certainly an ideal of mine, it also competes with the ideals of writing useful code that does useful things for my employer or the goals of my hobby project, and I'm not sure "getting actual useful things done" is necessarily LISP's strong suit, although I'm sure I'm ruffling feathers by saying so. I like more modern programming languages for other reasons, but their propensity to make backward-incompatible changes is definitely a point of frustration for me. Languages improving in backward-compatible ways is generally a good thing; your code can still be relatively "timeless" in such an environment. Some languages walk this line better than others.
Another point for stability is about how much a runtime can achieve if it is constantly improved over decades. Look where SBCL, a low-headcount project, is these days.
We should be very vigilant and ask for every "innovation" whether it is truly one. I think it is fair to assume for every person working in this industry for decades that the opinion would be that most innovations are just fads, hype and resume-driven development - the rest could be as well implemented as a library on top of something existing. The most progress we've had was in tooling (rust, go) which does not require language changes per se.
I think, the frustrating part about modern stacks is not the overwhelming amount of novelty, it is just that it feels like useless churn and the solutions are still as mediocre or even worse that what we've had before.
>There's no reason we can't be writing code that lasts 100 years.
There are many reason this is most likely not going to happen. Code despite best effort to achieve separation of concern (in the best case) is a highly contextual piece of work. Even with a simple program with no external library, there is a full compiler/interpreter ecosystem that forms a huge dependency. And hardware platforms they abstract from are also moving target. Change is the only constant, as we say.
>Imagine having this attitude with math: "LOL loser you still use polynomials!? Weren't those invented like thousands of years ago?
Well, that might surprise you, but no, they weren't. At least, they were not dealt with as they are thought and understood today in their contemporary most common presentation. When Babylonians (c. 2000 BCE) solved quadratic equation, they didn't have anything near Descartes algebraic notation connected to geometry, and there is a long series evolution in between, and still to this days.
Mathematicians actually do make a lot of fancy innovative things all the time. Some fundamentals stay stable over millennia, yes. But also some problem stay unsolved for millennia until some outrageous move is done out of the standard.
That's actually a good moment to wander about what an amazing they are, really.
Consider how vastly more accessible programming has become from 1950 until the present. Imagine if math had undergone a similar transition.
Mathematical notation evolved to its modern state over centuries. It's optimized heavily for its purpose. Version numbers? You're being facetious, right?
Yes, it evolved. It wasn't designed.
>Version numbers?
Without version numbers, it has to be backwards-compatible, making it difficult to remove cruft. What would programming be like if all the code you wrote needed to work as IBM mainframe assembly?
Tau is a good case study. Everyone seems to agree tau is better than pi. How much adoption has it seen? Is this what "heavy optimization" looks like?
It took hundreds of years for Arabic numerals to replace Roman numerals in Europe. A medieval mathematician could have truthfully said: "We've been using Roman numerals for hundreds of years; they work fine." That would've been stockholm syndrome. I get the same sense from your comment. Take a deep breath and watch this video: https://www.youtube.com/watch?v=KgzQuE1pR1w
>You're being facetious, right?
I'm being provocative. Not facetious. "Strong opinions, weakly held."
If there’s one thing that mathematical notation is NOT, it’s backwards compatible. Fields happily reuse symbols from other fields with slightly or even completely different meanings.
https://en.wikipedia.org/wiki/Glossary_of_mathematical_symbo... has lots of examples, for example
÷ (division sign)
Widely used for denoting division in Anglophone countries, it is no longer in common use in mathematics and its use is "not recommended". In some countries, it can indicate subtraction.
~ (tilde)
1. Between two numbers, either it is used instead of ≈ to mean "approximatively equal", or it means "has the same order of magnitude as".
2. Denotes the asymptotic equivalence of two functions or sequences.
3. Often used for denoting other types of similarity, for example, matrix similarity or similarity of geometric shapes.
4. Standard notation for an equivalence relation.
5. In probability and statistics, may specify the probability distribution of a random variable. For example, X∼N(0,1) means that the distribution of the random variable X is standard normal.
6. Notation for proportionality. See also ∝ for a less ambiguous symbol.
Individual mathematicians even are known to have broken backwards compatibility. https://en.wikipedia.org/wiki/History_of_mathematical_notati...
* Euler used i to represent the square root of negative one (√-1) although he earlier used it as an infinite number*
Even simple definitions have changed over time, for example:
- how numbers are written
- is zero a number?
- is one a number?
- is one a prime number?
Symbol reuse doesn't imply a break in backwards compatibility. As you suggest with "other fields", context allows determining how the symbols are used. It is quite common in all types of languages to reuse symbols for different purposes, relying on context to identify what purpose is in force.
Backwards incompatibility tells that something from the past can no longer be used with modern methods. Mathematical notation from long ago doesn't much look like what we're familiar with today, but we can still make use of it. It wasn't rendered inoperable by modern notation.
But few modern mathematicians can understand it. Given enough data, they can figure out what it means, but that’s similar to (in this somewhat weak analogy) running code in an emulator.
What we can readily make use of are mathematical results from long ago.
Right, whereas something that isn't backwards compatible couldn't be figured out no matter how much data is given. Consider this line of Python:
print(5 / 2)
There is no way you can know what the output should be. That is, unless we introduce synthetic context (i.e. a version number). Absent synthetic context we can reasonably assume that natural context is sufficient, and where natural context is sufficient, backwards compatibility is present.> What we can readily make use of are mathematical results from long ago.
To some degree, but mostly we've translated the old notation into modern notation for the sake of familiarity. And certainly a lot of programming that gets done is exactly that: Rewriting the exact same functionality in something more familiar.
But like mathematics, while there may have been a lot of churn in the olden days when nothing existed before it and everyone was trying to figure out what works, programming notation has largely settled on what is familiar with some reasonable stability and no doubt will only continue to find even greater stability and it matures in kind.
> Everyone seems to agree tau is better than pi. How much adoption has it seen?
> It took hundreds of years for Arabic numerals to replace Roman numerals in Europe.
What on earth does this have to do with version numbers for math? I appreciate this is Hacker News and we're all just pissing into the wind, but this is extra nonsensical to me.
The reason math is slow to change has nothing to do with backwards compatibility. We don't need to institute Math 2.0 to change mathematical notation. If you want to use tau right now, the only barrier is other people's understanding. I personally like to use it, and if I anticipate its use will be confusing to a reader, I just write `tau = 2pi` at the top of the paper. Still, others have their preference, so I'm forced to understand papers (i.e. the vast majority) which still use pi.
Which points to the real reason math is slow to change: people are slow to change. If things seem to be working one way, we all have to be convinced to do something different, and that takes time. It also requires there to actually be a better way.
> Is this what "heavy optimization" looks like?
I look forward to your heavily-optimized Math 2.0 which will replace existing mathematical notation and prove me utterly wrong.
Not sure this is the best example. Mathematical notation evolved a lot in the last thousand years. We're not using roman numerals anymore, and the invention of 0 or of the equal sign were incredible new features.
That is not counter to what I'm saying.
Mathematical notation <=> Programming Languages.
Proofs <=> Code.
When mathematical notation evolves, old proofs do not become obsolete! There is no analogy to a "breaking change" in math. The closest we came to this was Godel's Incompleteness Theorem and the Cambrian Explosion of new sets of axioms, but with a lot of work most of math was "re-founded" on a set of commonly accepted axioms. We can see how hostile the mathematical community is to "breaking changes" by seeing the level of crisis the Incompleteness Theorem caused.You are certainly free to use a different set of axioms than ZF(C), but you need to be very careful about which proofs you rely on; just as you are free to use a very different programming language or programming paradigm, but you may be limited in the libraries available to you. But if you wake up one morning and your code no longer compiles, that is the analogy to one day mathematicians waking up and realizing that a previously correct proof is now suddenly incorrect -- not that it was always wrong, but that changes in math forced it into incorrectness. It's rather unthinkable.
Of course programming languages should improve, diversify, and change over time as we learn more. Backward-compatible changes do not violate my principle at all. However, when we are faced with a possible breaking change to a programming language, we should think very hard about whether we're changing the original intent and paradigms of the programming language and whether we're better off basically making a new spinoff language or something similar. I understand why it's annoying that Python 2.7 is around, but I also understand why it'd be so much more annoying if it weren't.
Surely our industry could improve dramatically in this area if it cared to. Can we write a family of nested programming languages where core features are guaranteed not to change in breaking ways, and you take on progressively more risk as you use features more to the "outside" of the language? Can we get better at formalizing which language features we're relying on? Better at isolating and versioning our language changes? Better at time-hardening our code? I promise you there's a ton of fruitful work in this area, and my claim is that that would be very good for the long-term health and maturation of our discipline.
I disagree. The development of non-euclidean geometry broke a lot of theorems that were used for centuries but failed to generalize. All of a sudden, parallels could reach each other.
> Can we write a family of nested programming languages where core features are guaranteed not to change in breaking ways, and you take on progressively more risk as you use features more to the "outside" of the language?
We could, the problem is everyone disagrees on what that core should be. Should it be memory-efficient? Fast? Secure? Simple? Easy to formally prove? Easy for beginners? Work on old architecture? Work on embedded architecture? Depending on who you ask and what your goals are, you'll pick a different set of core features, and thus a different notation for your core language.
That's the difference between math & programming languages. Everyone agrees on math's overall purpose. It's a tool to understand, formalise and reason about abstractions. And mathematical notation should make that easier.
That being said, the most serious candidate for your "core language guaranteed not to change and that you can build onto" would be ANSI C. It's been there more more than 35 years, is a standard, is virtually everywhere, you can even write a conforming compiler for a brand new architecture, even an embedded microchip very easily, and most of not all the popular languages nowadays are build on it (C++ of course, but also C#, java, javascript, python, go, php, perl, haskell, rust, all have a C base), and they all use a C FFI. I'm not sure ANSI C was the best thing that ever happened to our industry, though.
What do any of these have to do with guarantees of long-term compatibility? I'm not arguing that there should be One Programming Language To Rule Them All, I'm asking about whether we can design better guarantees about long-term compatibility into new programming languages.
Math is continually updated, clarified and rewritten. 100 years ago was before the Bourbaki group.
And yet math proofs from decades and centuries ago are still correct. Note that I said we write "code that lasts", not "programming languages that never change". Math notation is to programming languages as proofs are to code. I am not saying programming languages should never change or improve. I am saying that our entire industry would benefit if we stopped to think about how to write code that remains "correct" (compiling, running, correct behavior) for the next 100 years. Programming languages are free to change in backward-compatible ways, as long once-correct code is always-correct. And it doesn't have to be all code, but you know what they say: there is nothing as permanent as a temporary solution.
I understand some of your frustration, but often the newness is in response to a need for completeness or correctness. "As we've explored how to use the system, we've found some parts were missing/bad and would be better with [new thing]". That's certainly what's happening with Python.
It's like the Incompleteness Theorem, but applied to software systems.
It takes a strong will to say "no, the system is Done, warts and missing pieces and all. Deal With It". Everyone who's had to deal with TeX at any serious level can point to the downsides of that.
But you have a point, and it's not just "our industry", it's society at large that has abandoned the old in favour of incessant forgetfulness and distaste for tradition and history. I'm by no means a nostalgic but I still mourn the harsh disjoint between contemporary human discourse and historical. Some nerds still read Homer and Cicero and Goethe and Ovid and so on but if you use a trope from any of those that would have been easily recognisable as such by europeans for much of the last millenium you can be quite sure that it won't generally be recognised today.
This also means that a lot of early and mid-modern literature is partially unavailable to contemporary people, because it was traditional to implicitly use much older motifs and riff on them when writing novels and making arguments, and unless you're aware of that older material you'll miss out on it. For e.g. Don Quixote most would need an annotated version which points out and makes explicit all the references and riffing, basically destroying the jokes by explaining them upfront.
Btw, equations and polynomials while conceptually are old, our contemporary notation is much younger, dating to the 16th century, and many aspects of mathematical notation are younger still.
Even C/C++ introduces breaking changes from time to time (after decades of deprecation though).
There’s no practical reason why Python should commit to a 100+ year code stability, as all that comes at a price.
Having said that, Python 2 -> 3 is a textbook example of how not to do these things.
C in contrast generally versions the breaking changes in the standard, and you can keep targeting an older standard on a newer compiler if you need to, and many do
The weather forecast is also “just math”, yet yesterday’s won’t be terribly useful next April.
weather forecasting models <=> code <=> math
weather forecast <=> program output <=> calculation results
So all you're saying is that we should not expect individual weather forecasts, program output, and calculation results to be useful long-term. Nobody is arguing that.But my larger point actually also stands: Weather forecast models also, in the end, incorporate information about geography, likely temperature conditions etc., and might not be stable over 100 years.
The more interesting question is probably: Is Python more like the weather or a weather forecasting model? :)
Howeveeerrr.. its not quite math when you break down to the electronics level, unless you go really wild (wild meaning physics math). take a breakdown of python to assembly to binary that flips the transistors doing the thing. You can mathematically define that each transistor will be Y when that value of O is X(N); btw sorry i can't think of a better way to define such a thing from mobile here. And go further by defining voltages to be applied, when and where, all mathematically.
In reality its done in sections. At the electronic level math defines your frequency, voltage levels, timing, etc; at the assembly level, math defines what comparisons of values to be made or what address to shift a value to and how to determine your output; lastly your interpreter determines what assembly to use based on the operations you give it, and based on those assembly operations, ex an "if A == B then C" statement in code is actually a binary comparator that checks if the value at address A is the same as the value at address B.
You can get through a whole stack with math, but much of it has been abstracted away into easy building blocks that don't require solving a huge math equation in order to actually display something.
You can even find mathematical data among datasheets for electronic components. They say (for example) over period T you cant exceed V volts or W watts, or to trigger a high value you need voltage V for period T but it cannot exceed current I. You can define all of your components and operations as an equation, but i dont think its really done anymore as a practice, the complexity level of doing so (as someone not building a cpu or any ic) isnt useful unless youre working on a physics paper or quantum computing, etc etc
Most of my python from that era also works (python 3.1)
The problem is not really the language syntax, but how libraries change a lot.
I dunno man, there's an equal amount of bullshit that still exists only because that's how it was before we were born.
> Code is just math.
What?? No. If it was there'd never be any bugs.
> What?? No. If it was there'd never be any bugs.
Are you claiming there is no incorrect math out there? Go offer to grade some high-school algebra tests if you'd like to see buggy math. Or Google for amateur proofs of the Collatz Conjecture. Math is just extremely high (if not all the way) on the side of "if it compiles, it is correct", with the caveat that compilation only can happen in the brains of other mathematicians.
In math, `a - b` doesn't occasionally become `b - a` if one CPU/thread/stream finishes before an other, just to give one example.
Or, if you write `1 + 2` it will forever be `1 + 2`, unlike code where it may become `3 / 4 - 5 + 6 ^ 7 + 1 + 2` or whatever junk gets appended before or after your expression tomorrow (analogy for the OS/environment your code runs in)
I guess to put it simply: code is affected by its environment, math isn't.
Anyhoo, remarks like this are why the real ones use Typst now. TeX and family are stagnant, difficult to use, difficult to integrate into modern workflows, and not written in Rust.
Are you intentionally leaning into the exact caricature I'm referring to? "Real programmers only use Typstly, because it's the newest!". The website title for Typst when I Googled it literally says "The new foundation for documents". Its entire appeal is that it's new? Thank you for giving me such a perfect example of the symptom I'm talking about.
> TeX and family are stagnant, difficult to use, difficult to integrate into modern workflows, and not written in Rust.
You've listed two real issues (difficult to use, difficult to integrate), and two rooted firmly in recency bias (stagnant, not written in Rust). If you can find a typesetting library that is demonstrably better in the ways you care about, great! That is not an argument that TeX itself should change. Healthy competition is great! Addiction to change and newness is not.
> nobody uses infinitesimals for derivatives anymore, they all use limits now
My point is not that math never changes -- it should, and does. However, math does not simply rot over time, like code seems to (or at least we simply assume it does). Math does not age out. If a math technique becomes obsolete, it's only ever because it was replaced with something better. More often, it forks into multiple different techniques that are useful for different purposes. This is all wonderful, and we can celebrate when this happens in software engineering too.
I also think your example is a bit more about math pedagogy than research -- infinitesimals are absolutely used all the time in math research (see Nonstandard Analysis), but it's true that Calculus 1 courses have moved toward placing limits as the central idea.
Just in the same sense that CS does not age out. Most concepts stick, but I'm pretty sure you didn't go through Στοιχεία (The Elements) in its original version. I'm also pretty confident that most people out there that use many of the notion it holds and helped to spread never threw their eyes over a single copy of it in their native language.
This is like saying "you haven't read the source code of the first version of Linux". The only reason to do that would be for historical interest. There is still something timeless about it, and I absolutely did learn Euclid's postulates which he laid down in those books, all 5 of which are still foundational to most geometry calculations in the world today, and 4 of which are foundational to even non-Euclidean geometry. The Elements is a perfect example of math that has remained relevant and useful for thousands of years.
It might not be the best tagline, but that is most certainly not the entire appeal of Typst. It is a huge improvement over Latex in many ways.
All auto-differentiation libraries today are built off of infinitesimals via Dual numbers. Literally state of the art.