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I always intended "Programming in the 21st Century" to have a limited run. I knew since the entry from January 1, 2010, that I needed to end it. It just took a while.Recovering Programmer And now, an explanation. I started this blog to talk about issues tangentially related to programming, about soft topics like creativity and inspiration and how code is a medium for implementing creative visions. Instead I worked through more technical topics that I'd been kicking around over the years. That was fun! is something I would have loved to read in 1998. More than once I've googled around and ended up back at one of my essays.Purely Functional Retrogames As I started shifting gears and getting back toward what I originally wanted to do, there was one thing that kept bothering me: the word in the title.programming I don't think of myself as a programmer. I write code, and I often enjoy it when I do, but that term is both limiting and distracting. I don't want to program for its own sake, not being interested in the overall experience of what I'm creating. If I start thinking too much about programming as a distinct entity then I lose sight of that. Now that I've exhausted what I wanted to write about, I can clear those topics out of my head and focus more on using technology to make fun things.programmer Thanks for reading! It's hard to sum up 200+ articles, but here's a start. This is not even close to a full index. See the if you want everything. (There are some bits in there.)archivesodd Also see the for all of the functional programming articles.previous entry is something I wrote in 2004 which used to be linked from every prog21 entry.Programming as if Performance Mattered widely linked popular on creativity others that I like Erlang retro Things That Turbo Pascal is Smaller Than Do You Really Want to be Doing This When You're 50? Organizational Skills Beat Algorithmic Wizardry Retiring Python as a Teaching Language Computer Science Courses that Don't Exist, But Should Five Memorable Books About Programming A Spellchecker Used to Be a Major Feat of Software Engineering Want to Write a Compiler? Just Read These Two Papers. On Being Sufficiently Smart Optimizing for Fan Noise Free Your Technical Aesthetic from the 1970s Advice to Aimless, Excited Programmers Write Code Like You Just Learned How to Program Don't Distract New Programmers with OOP Recovering From a Computer Science Education Don't Fall in Love With Your Technology A Complete Understanding is No Longer Possible Solving the Wrong Problem This is Why You Spent All that Time Learning to Program We Who Value Simplicity Have Built Incomprehensible Machines Your Coding Philosophies are Irrelevant The Silent Majority of Experts Hopefully More Controversial Programming Opinions How much memory does malloc(0) allocate? The Pure Tech Side is the Dark Side Flickr as a Business Simulator How to Think Like a Pioneer What Do People Like? Accidental Innovation, Part 1 If You're Not Gonna Use It, Why Are You Building It? It's Like That Because It Has Always Been Like That Trapped by Exposure to Pre-Existing Ideas Get Good at Idea Generation You Can't Sit on the Sidelines and Become a Philosopher The Software Developer's Sketchbook Design is Expensive Why Doesn't Creativity Matter in Tech Recruiting? Deriving Forth Tales of a Former Disassembly Addict Living Inside Your Own Black Box Tricky When You Least Expect It The Most Important Decisions are Non-Technical Things to Optimize Besides Speed and Memory All that Stand Between You and a Successful Project are 500 Experiments The UNIX Philosophy and a Fear of Pixels Dangling by a Trivial Feature Documenting the Undocumentable You Don't Want to Think Like a Programmer You Don't Read Code, You Explore It If You Haven't Done It Before, All Bets Are Off What Can You Put in a Refrigerator? The Same User Interface Mistakes Over and Over Fun vs. Computer Science A Deeper Look at Tail Recursion in Erlang My Road to Erlang Garbage Collection in Erlang How to Crash Erlang Eleven Years of Erlang A Ramble Through Erlang IO Lists A Concurrent Language for Non-Concurrent Software A Peek Inside the Erlang Compiler Evolution of an Erlang Style A Personal History of Compilation Speed Slow Languages Battle Across Time How Much Processing Power Does it Take to be Fast? 8-Bit Scheme: A Revisionist History Stumbling Into the Cold Expanse of Real Programming Why Do Dedicated Game Consoles Exist? Lost Lessons from 8-Bit BASIC Programming Modern Systems Like It Was 1984
We've all seen progress bars that move slowly for twenty minutes, then rapidly fill up in the last 30 seconds. Or the reverse, where a once speedy bar takes 50% of the time covering the last few pixels. And bars that occasionally jump backward in time are not the rarity you'd expect them to be. Even this past month, when I installed the macOS Sierra update, the process completed when the progress bar was only two-thirds full. DOOM 2016 has a circular progress meter for level loads, with the percent-complete in the center. It often sits for a while at 0%, gets stuck at 74% and 99%, and sometimes finishes in the 90s before reaching 100%. Clearly this is not a trivial problem, or these quirks would be behind us. Conceptually, a perfect progress bar is easy to build. All you need to know is exactly how long the total computation will take, then update the bar in its own thread so it animates smoothly. Simple! Why do developers have trouble with this? Again, all you need to know is ...exactly how long Oh. You could time it with a stopwatch and use that value, but that assumes your system is the standard, and that other people won't have faster or slower processors, drives, or internet connections. You could run a little benchmark and adjust the timing based on that, but there are too many factors. You could refine the estimate mid-flight, but this is exactly the road that leads to the bar making sudden jumps into the past. It's all dancing around that you can't know ahead of time exactly how long it should take for the progress bar to go from empty to full. There's a similar problem in process scheduling, where there are a number of programs to run sequentially in batch mode. One program at a time is selected to run to completion, then the next. If the goal is to have the lowest average time for programs being completed, then best criteria for choosing the next program to run is the one with the shortest execution time (see ). But this requires knowing how long each program will take before running it, and that's not possible in the general case.shortest job next And so the perfect progress bar is forever out of reach, but they're still useful, as established by Brad Allan Meyers in his 1985 paper ("The importance of percent-done progress indicators for computer-human interfaces"). But "percent-done" of what? It's easy to map the loading of a dozen similarly sized files to an overall percentage complete. Not so much when all kinds of downloading and local processing is combined together into a single progress number. At that point the progress bar loses all meaning except as an indication that there's some sort of movement toward a goal, and that mostly likely the application hasn't hasn't locked up. (If you liked this, you might enjoy .)An Irrational Fear of Files on the Desktop
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<![CDATA[I'm exploring another corner of the Interlisp ecosystem and history: the Interlisp-10 implementation for DEC PDP-10 mainframes, a 1970s character based environment that predated the graphical Interlisp-D system. I approached this corner when I set out to learn and experiment with a tool I initially checked out only superficially, the TTY editor. This command line structure editor for Lisp code and expressions was the only one of Interlisp-10. The oldest of the Interlisp editors, it came before graphical interfaces and SEdit. On Medley Interlisp the TTY editor is still useful for specialized tasks. For example, its extensive set of commands with macro support is effectively a little language for batch editing and list structure manipulation. Think Unix sed for s-exps. The language even provides the variable EDITMACROS (wink wink). Evaluating (PRINTDEF EDITMACROS) gives a flavor for the language. For an experience closer to 1970s Interlisp I'm using the editor in its original environment, Interlisp-10 on TWENEX. SDF provides a publicly accessible TWENEX system running on a PDP-10 setup. With the product name TOPS-20, TWENEX was a DEC operating system for DECSYSTEM-20/PDP-10 mainframes derived from TENEX originally developed by BBN. SDF's TWENEX system comes with Interlisp-10 and other languages. This is Interlisp-10 in a TWENEX session accessed from my Linux box: A screenshot of a Linux terminal showing Interlisp-10 running under TWENEX in a SSH session. Creating a TWENEX account is straightforward but I didn't receive the initial password via email as expected. After reporting this to the twenex-l mailing list I was soon emailed the password which I changed with the TWENEX command CHANGE DIRECTORY PASSWORD. Interacting with TWENEX is less alien or arcane than I thought. I recognize the influence of TENEX and TWENEX on Interlisp terminology and notation. For example, the Interlisp REPL is called Exec after the Exec command processor of the TENEX operating system. And, like TENEX, Interlisp uses angle brackets as part of directory names. It's clear the influence of these operating systems also on the design of CP/M and hence MS-DOS, for example the commands DIR and TYPE. SDF's TWENEX system provides a complete Interlisp-10 implementation with only one notable omission: HELPSYS, the interactive facility for consulting the online documentation of Interlisp. The SDF wiki describes the basics of using Interlisp-10 and editing Lisp code with the TTY editor. After a couple of years of experience with Medley Interlisp the Interlisp-10 environment feels familiar. Most of the same functions and commands control the development tools and facilities. My first impression of the TTY editor is it's reasonably efficient and intuitive to edit Lisp code, at least using the basic commands. One thing that's not immediately apparent is that EDITF, the entry point for editing a function, works only with existing functions and can't create new ones. The workaround is to define a stub from the Exec like this: (DEFINEQ (NEW.FUNCTION () T)) and then call (EDITF NEW.FUNCTION) to flesh it out. Transferring files between TWENEX and the external world, such as my Linux box, involves two steps because the TWENEX system is not accessible outside of SDF. First, I log into Unix on sdf.org with my SDF account and from there ftp to kankan.twenex.org (172.16.36.36) with my TWENEX account. Once the TWENEX files are on Unix I access them from Linux with scp or sftp to sdf.org. This may require the ARPA tier of SDF membership. Everything is ready for a small Interlisp-10 programming project. #Interlisp #Lisp a href="https://remark.as/p/journal.paoloamoroso.com/exploring-interlisp-10-and-twenex"Discuss.../a Email | Reply @amoroso@oldbytes.space !--emailsub--]]>
Total disassociation, fully out your mind That Funny Feeling I was thinking today about a disc jockey. Like one in the 80s, where you actually had to put the records on the turntables to get the music. You move the information. You were the file system. I like the Retro Game Mechanics channel on YouTube. What was possible was limited by the hardware, and in a weird way it forced games to be good. Skill was apparent by a quick viewing, and different skill is usually highly correlated. Good graphics meant good story – not true today. I was thinking about all the noobs showing up to comma. If you can put a technical barrier up to stop them, like it used to be. But you can’t. These barriers can’t be fake, because a fake barrier isn’t like a real barrier. A fake barrier is one small patch away from being gone. What if the Internet was a mistake? I feel like it’s breaking my brain. It was this mind expanding world in my childhood, but now it’s a set of narrow loops that are harder and harder to get out of. And you can’t escape it. Once you have Starlink to your phone, not having the Internet with you will be a choice, not a real barrier. There’s nowhere to hide. Chris McCandless wanted to be an explorer, but being born in 1968 meant that the world was already all explored. His clever solution, throw away the map. But that didn’t make him an explorer, it made him an idiot who died 5 miles from a bridge that would have saved his life. And I’ll tell you something else that you ain’t dying enough to know Big Casino Sure, you can still spin real records, code for the NES, and SSH into your comma device. But you don’t have to. And that makes the people who do it come from a different distribution from the people who used to. They are not explorers in the same way Chris McCandless wasn’t. When I found out about the singularity at 15, I was sure it was going to happen. It was depressing for a while, realizing that machines would be able to do everything a lot better than I could. But then I realized that it wasn’t like that yet and I could still work on this problem. And here I am, working in AI 20 years later. I thought I came to grips with obsolescence. But it’s not obsolescence, the reality is looking to be so much sadder than I imagined. It won’t be humans accepting the rise of the machines, it won’t be humans fighting the rise of the machines, it will be human shaped zoo animals oddly pacing back and forth in a corner of the cage while the world keeps turning around them. It’s easy to see the appeal of conspiracy theories. Even if they hate you, it’s more comforting to believe that they exist. That at least somebody is driving. But that’s not true. It’s just going. There are no longer Western institutions capable of making sense of the world. (maybe the Chinese ones can? it’s hard to tell) We are shoved up brutally against evolution, just of the memetic variety. The TikTok brainrot kids will be nothing compared to the ChatGPT brainrot kids. And I’m not talking like an old curmudgeon about the new forms of media being bad and the youth being bad like Socrates said. Because you can never go back. It will be whatever it is. To every fool preaching the end of history, evolution spits in your face. To every fool preaching the world government AI singleton, evolution spits in your face. I knew these things intellectually, but viscerally it’s just hard to live through. The world feels so small and I feel like I’m being stared at by the Eye of Sauron.
I always had a diffuse idea of why people are spending so much time and money on amateur radio. Once I got my license and started to amass radios myself, it became more clear.
What does it mean when someone writes that a programming language is “strongly typed”? I’ve known for many years that “strongly typed” is a poorly-defined term. Recently I was prompted on Lobsters to explain why it’s hard to understand what someone means when they use the phrase. I came up with more than five meanings! how strong? The various meanings of “strongly typed” are not clearly yes-or-no. Some developers like to argue that these kinds of integrity checks must be completely perfect or else they are entirely worthless. Charitably (it took me a while to think of a polite way to phrase this), that betrays a lack of engineering maturity. Software engineers, like any engineers, have to create working systems from imperfect materials. To do so, we must understand what guarantees we can rely on, where our mistakes can be caught early, where we need to establish processes to catch mistakes, how we can control the consequences of our mistakes, and how to remediate when somethng breaks because of a mistake that wasn’t caught. strong how? So, what are the ways that a programming language can be strongly or weakly typed? In what ways are real programming languages “mid”? Statically typed as opposed to dynamically typed? Many languages have a mixture of the two, such as run time polymorphism in OO languages (e.g. Java), or gradual type systems for dynamic languages (e.g. TypeScript). Sound static type system? It’s common for static type systems to be deliberately unsound, such as covariant subtyping in arrays or functions (Java, again). Gradual type systems migh have gaping holes for usability reasons (TypeScript, again). And some type systems might be unsound due to bugs. (There are a few of these in Rust.) Unsoundness isn’t a disaster, if a programmer won’t cause it without being aware of the risk. For example: in Lean you can write “sorry” as a kind of “to do” annotation that deliberately breaks soundness; and Idris 2 has type-in-type so it accepts Girard’s paradox. Type safe at run time? Most languages have facilities for deliberately bypassing type safety, with an “unsafe” library module or “unsafe” language features, or things that are harder to spot. It can be more or less difficult to break type safety in ways that the programmer or language designer did not intend. JavaScript and Lua are very safe, treating type safety failures as security vulnerabilities. Java and Rust have controlled unsafety. In C everything is unsafe. Fewer weird implicit coercions? There isn’t a total order here: for instance, C has implicit bool/int coercions, Rust does not; Rust has implicit deref, C does not. There’s a huge range in how much coercions are a convenience or a source of bugs. For example, the PHP and JavaScript == operators are made entirely of WAT, but at least you can use === instead. How fancy is the type system? To what degree can you model properties of your program as types? Is it convenient to parse, not validate? Is the Curry-Howard correspondance something you can put into practice? Or is it only capable of describing the physical layout of data? There are probably other meanings, e.g. I have seen “strongly typed” used to mean that runtime representations are abstract (you can’t see the underlying bytes); or in the past it sometimes meant a language with a heavy type annotation burden (as a mischaracterization of static type checking). how to type So, when you write (with your keyboard) the phrase “strongly typed”, delete it, and come up with a more precise description of what you really mean. The desiderata above are partly overlapping, sometimes partly orthogonal. Some of them you might care about, some of them not. But please try to communicate where you draw the line and how fuzzy your line is.
