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  • 23 Comments
Joined 1 year ago
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Cake day: June 14th, 2023

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  • Null is terrible.

    A lot of languages have it available as a valid return value for most things, implicitly. This also means you have to do extra checking or something like this will blow up with an exception:

    // java example
    // can throw exception
    String address = person.getAddress().toUpperCase();
    
    // safe
    String address = "";
    if (person.getAddress() != null) {
        person.getAddress().toUpperCase();
    }
    

    There are a ton of solutions out there. Many languages have added null-coalescing and null-conditional operators – which are a shorthand for things like the above solutions. Some languages have removed the implicit nulls (like Kotlin), requiring them to be explicitly marked in their type. Some languages have a wrapper around nullable values, an Option type. Some languages remove null entirely from the language (I believe Rust falls into this, using an option type in place of).

    Not having null isn’t particularly common yet, and isn’t something languages can just change due to breaking backwards compatibility. However, languages have been adding features over time to make nulls less painful, and most have some subset of the above as options to help.

    I do think Option types are fantastic solutions, making you deal with the issue that a none/empty type can exist in a particular place. Java has had them for basically 10 years now (since Java 8).

    // optional example
    
    Class Person {
        private String address;
        
        //prefer this if a null could ever be returned
        public Optional<String> getAddress() {
            return Optional.ofNullable(address);
        }
        
        // not this
        public String getAddress() {
            return address;
        }
    

    When consuming, it makes you have to handle the null case, which you can do a variety of ways.

    // set a default
    String address = person.getAddress().orElse("default value");
    
    // explicitly throw an exception instead of an implicit NullPointerException as before
    String address = person.getAddress().orElseThrow(SomeException::new);
    
    // use in a closure only if it exists
    person.getAddress().ifPresent(addr -> logger.debug("Address {}", addr));
    
    // first example, map to modify, and returning default if no value
    String address = person.getAddress().map(String::toUpperCase).orElse("");
    

  • While so many things are so much better than they used to be in the programming ecosystem, I feel like entry-level GUI programming is so much worse.

    This will probably be an unpopular opinion, but Visual Basic (pre .NET) was one of the easiest ways to make a simple, contemporary (for the time) GUI. Drag and drop some elements, modify the UI properties, double click and add code. It made for an excellent introduction to programming because the UI portions were simple and intuitive enough to stay out of the way.

    The rest of VB wasn’t great. Weird language/syntax/keywords keywords, closed environment, mediocre tooling. But for building UIs? I haven’t used anything as easy as that and it’s been over 20 years now…

    I don’t have any recommendations unfortunately. Almost everything I do is web based or command line. Web UIs aren’t terrible, but there’s a learning curve and lots of limitations. Haven’t found anything for desktop apps I like lately (last one I built was also with tkinter for a small Python project. Bleh.)



  • Java

    My take on a modern Java solution (parts 1 & 2).

    spoiler
    package thtroyer.day1;
    
    import java.util.*;
    import java.util.stream.IntStream;
    import java.util.stream.Stream;
    
    
    public class Day1 {
        record Match(int index, String name, int value) {
        }
    
        Map numbers = Map.of(
                "one", 1,
                "two", 2,
                "three", 3,
                "four", 4,
                "five", 5,
                "six", 6,
                "seven", 7,
                "eight", 8,
                "nine", 9);
    
        /**
         * Takes in all lines, returns summed answer
         */
        public int getCalibrationValue(String... lines) {
            return Arrays.stream(lines)
                    .map(this::getCalibrationValue)
                    .map(Integer::parseInt)
                    .reduce(0, Integer::sum);
        }
    
        /**
         * Takes a single line and returns the value for that line,
         * which is the first and last number (numerical or text).
         */
        protected String getCalibrationValue(String line) {
            var matches = Stream.concat(
                            findAllNumberStrings(line).stream(),
                            findAllNumerics(line).stream()
                    ).sorted(Comparator.comparingInt(Match::index))
                    .toList();
    
            return "" + matches.getFirst().value() + matches.getLast().value();
        }
    
        /**
         * Find all the strings of written numbers (e.g. "one")
         *
         * @return List of Matches
         */
        private List findAllNumberStrings(String line) {
            return IntStream.range(0, line.length())
                    .boxed()
                    .map(i -> findAMatchAtIndex(line, i))
                    .filter(Optional::isPresent)
                    .map(Optional::get)
                    .sorted(Comparator.comparingInt(Match::index))
                    .toList();
        }
    
    
        private Optional findAMatchAtIndex(String line, int index) {
            return numbers.entrySet().stream()
                    .filter(n -> line.indexOf(n.getKey(), index) == index)
                    .map(n -> new Match(index, n.getKey(), n.getValue()))
                    .findAny();
        }
    
        /**
         * Find all the strings of digits (e.g. "1")
         *
         * @return List of Matches
         */
        private List findAllNumerics(String line) {
            return IntStream.range(0, line.length())
                    .boxed()
                    .filter(i -> Character.isDigit(line.charAt(i)))
                    .map(i -> new Match(i, null, Integer.parseInt(line.substring(i, i + 1))))
                    .toList();
        }
    
        public static void main(String[] args) {
            System.out.println(new Day1().getCalibrationValue(args));
        }
    }
    
    





  • Yep, absolutely.

    In another project, I had some throwaway code, where I used a naive approach that was easy to understand/validate. I assumed I would need to replace it once we made sure it was right because it would be too slow.

    Turns out it wasn’t a bottleneck at all. It was my first time using Java streams with relatively large volumes of data (~10k items) and it turned out they were damn fast in this case. I probably could have optimized it to be faster, but for their simplicity and speed, I ended up using them everywhere in that project.


  • I’ve got so many more stories about bad optimizations. I guess I’ll pick one of those.

    There was an infamous (and critical) internal application somewhere I used to work. It took in a ton of data, putting it in the database, and then running a ton of updates to populate various fields and states. It was something like,

    • Put all data in x table with batch y.
    • Update rows in batch y with condition a, set as type a. (just using letters as placeholders for real states)
    • Update rows in batch y that haven’t been updated and have condition b, set as type b.
    • Update rows in batch y that haven’t been updated and have condition c, set as type c.
    • Update rows in batch y that have condition b and c and condition d, set as type d.
    • (Repeat many, many times)

    It was an unreadable mess. Trying to debug it was awful. Business rules encoded as a chain of sql updates are incredibly hard to reason about. Like, how did this row end up with that data??

    Me and a coworker eventually inherited the mess. Once we deciphered exactly what the rules were and realized they weren’t actually that complicated, we changed the architecture to:

    • Pull data row by row (instead of immediately into a database)
    • Hydrate the data into a model
    • Set up and work with the model based on the business rules we painstakingly reverse engineered (i.e. this row is type b because conditions x,y,z)
    • Insert models to database in batches

    I don’t remember the exact performance impact, but it wasn’t markedly faster or slower than the previous “fast” SQL-based approach. We found and fixed numerous bugs, and when new issues came up, issues could be fixed in hours rather than days/weeks.

    A few words of caution: Don’t assume that building things with a certain tech or architecture will absolutely be “too slow”. Always favor building things in a way that can be understood. Jumping to the wrong tool “because it’s fast” is a terrible idea.

    Edit: fixed formatting on Sync



  • I think that’s a fair argument. PICO-8 definitely could be called a primitive IDE. I think it’s closer to being a primitive game engine with so much of its focus being on graphics and sound tooling.

    While you can code simple things within PICO-8, I’ve found that as I’ve built bigger things, I work better in an outside editor, even if it only gets me smaller fonts, splitable windows, vim bindings, limited linting, and somewhat broken code completion.

    This isn’t a criticism of PICO-8 as an environment. I think there are a lot of strengths in its simplicity, especially for beginner coders.

    I tend to make a distinction between a customizable editor with some support for a language (like vim+plugins) vs a dedicated all-in-one tool that fully understands the language and environment (IDE). PICO-8 is hard to place on that spectrum given it’s an all-in-one tool, but switching to a modified editor gives you more features.


  • This is a very strange article to me.

    Do some tasks run slower today than they did in the past? Sure. Are there some that run slower without a good reason? Sure.

    But the whole article just kind of complains. It never acknowledges that many things are better than they used to be. It also just glosses over the complexities and tradeoffs people have to make in the real world.

    Like this:

    Windows 10 takes 30 minutes to update. What could it possibly be doing for that long? That much time is enough to fully format my SSD drive, download a fresh build and install it like 5 times in a row.

    I don’t know what exactly is involved in Windows updates, but it’s likely 1) a lot of data unpacking, 2) a lot of file patching, and 3) done in a way that hopefully won’t bork your system if something goes wrong.

    Sure, reinstalling is probably faster, but it’s also simpler. If your doctor told you, “The cancer is likely curable. Here’s the best regimen to get you there over the next year”, it would be insane to say, “A YEAR!? I COULD MAKE A WHOLE NEW HUMAN IN A YEAR!” But I feel like the article is doing exactly that, over and over.


  • I’m reluctant to call much “bloat”, because even if I don’t use something doesn’t mean it isn’t useful, to other people or future me.

    I used to code in vim (plus all sorts of plugins), starting in college where IDEs weren’t particularly encouraged or necessary for small projects. I continued to use this setup professionally because it worked well enough and every IDE I tried for the main language I was using wasn’t great.

    However, I eventually found IDEs that worked for the language(s) I needed and I don’t have any interest in going back to a minimalistic (vim or otherwise) setup again. It’s not that the IDE does things that can’t be done with vim generally, but having a tool that understands the code, environment, and provides useful tooling is invaluable to me. I find being able to do things with some automation (like renaming or refactoring) is so much safer, faster, and enjoyable than doing it by hand.

    Features I look for/use most often:

    • Go to (both definition and usages)
    • Refactor tooling (renaming, inlining, extracting, etc).
    • Good warnings, along with suggested solutions. Being able to apply solution is a plus.
    • Framework integrations
    • User-friendly debugger. Ability to pause, drill in, and interact with data is immensely helpful with the type of applications I work on.
    • Configurable breakpoints.
    • Build tool integrations. Doing it on the console is… fine… but being able to set up what I need easily in the IDE is preferable.

    Features I don’t use or care so much about? Is there much left?

    • My IDE can hook up to a database. I’ve tried it a few times, but it never seemed particularly useful for the apps I work on.
    • git integration. I have a separate set of tools I normally work with. The ones in my IDE are fine, but I usually use others.
    • Profiler. I use it on occasion, but only a few times a year probably.

    I do code in non-IDE environments from time to time, but this is almost always because of a lack of tooling than anything else. (Like PICO-8 development)



  • I’m somewhat confused by your statements, so perhaps I don’t understand.

    Function/objects that allow changing their behavior by passing different objects into them, based on some interface, is called dependency injection. Some subset of behavior is determined by this passed behavior. E.g. To keep a logger class from having to understand how to write logs, you could create a WriteTo interface and various implementations like WriteToDatabase, WriteToFile, WriteToStdout, WriteToNull.

    When you create this example logger, you’ll need to make a choice of what object to pass when you write the code. e.g. new Logger(new WriteToDatabase(config)) But maybe you don’t want to make that decision yet – you want to let a config file decide which writer(s) to create. The pattern to pick between dependencies at runtime is called a factory. In this case, you might make a WriterFactory to pick the right writer, or perhaps a LoggerFactory to hide the creation of both Writer and Factory objects.

    So, a factory is only really a facade to hide the runtime switching of how an object is created.

    Also, the term dependency injection often gets confused with what you see in various Java / C# / and various frameworks in other languages – those usually use what’s called a “DI Container” or “IoC Container”. These manage and facilitate how dependency injection happens within the project, often with various annotations (e.g.@Autowired). These containers are powerful, but sometimes complicated.

    However, you can absolutely still do DI without DI containers, and I think advocating for not using DI generally (and related patterns like factories) is rather misguided.