Concepts to help developers master JavaScript
github.com
github.com
In this list of 33 JavaScript concepts, I count 11 that either do not exist in Elm or, like Object.assign, do not have an alternative to worry about:
No reference types
No type coercion
No == vs ===, although typeof has a simpler equivalent
Basically all expressions and no statements
No hoisting as such
No prototypical inheritance or prototype chain
No Object.create, no destructive alternative to Object.assign
No factories or classes as such
No inheritance or polymorphism
No design patterns as such, though you could argue that abstract algebra or category theory are the replacements
No this, call, bind, or apply
The finer points of these are somewhat debatable, but overall my contention is that removing mutation and local state makes a lot of related concepts just fall away. A takeaway is that when someone tells you that they’ve learned Elm, you needn’t assume that this was as huge of an undertaking as learning JavaScript.
Sure, but elm has its own issues with comparison as these are essentially implemented as a compiler hack, and only comparable (ie primitive or lists/tulles thereof) types can be used as keys for the built in map type (so you need to know about primitive types too)
If you don't use ES5 stuff that was replaced in newer versions, things get much simpler.
let, =>, === etc.
I think that casts this post in a different light. If the repo's intent is that "every JS developer should know" everything on this list, the context of this discussion changes.
http://dmitrysoshnikov.com/ecmascript/javascript-the-core-2n...
Just like everything else (especially programming languages), you are limited by your understanding of the concepts. It's only as difficult as you make it.
I think so many people think of it as a toy, never bother to actually learn how it works, and assume everything either does or should work like it does in other languages.
I disagree. It is very possible to understand a concept fully, but for it still to be hard. E.g. pointers are quite easy to grasp the concept of, but also very easy to mess up. A more related example would be JavaScript's type coercion. Just understanding it, doesn't make it easy to avoid overlooking places it will cause problems. So some features programming languages include can be objectively considered harder than others, even when you fully understand them.
At the moment, I actually prefer vanilla javascript to ES6-7. ES6 is inconsistent in awful ways. You still can't rely on bindings to stay put and new additions like the splat operator just don't work the same way all the time.
The more I learn JS, the more I hate it. I think eventually the web development community will come around, Node will lose mindshare, and compile-to-js languages will find their place in the sun again.
I suspect that people who actually like the language are experiencing a form of Stockholm Syndrome.
ES6 is vanilla JavaScript. Most modern browsers have support >98% of added ES6 functionality for several major versions at this point. Admittedly, Node.js is still lacking, but it's getting there.
> You still can't rely on bindings to stay put and new additions like the splat operator just don't work the same way all the time.
Unless you have a bug to report about undefined or non-deterministic behavior, then it must be something you're doing. Random functionality is not intended behavior.
> eventually the web development community will come around... and compile-to-js languages will find their place in the sun again.
This is implying they were ever there. The big ones that come to mind were terrible. They would produce way more bloated frontends than anything we see today. In general, adding a layer of abstraction can be incredibly useful sometimes, but they can come at a steep cost.
What you include in "compile-to-JS" does get a little tricky to define, though. Things like TypeScript or even Babel can kind of count here. I think we will likely continue to see these, but I seriously doubt we'll see a resurgence of anything like GWT again.
> I suspect that people who actually like the language are experiencing a form of Stockholm Syndrome.
Sure, but the same can be said for anybody working with computers ;)
You wouldn't be saying that if you ran into the behavior we have. Eventually I'll do more digging to find out root cause. But there's no way it was us.
> I seriously doubt we'll see a resurgence of anything like GWT again.
I'm thinking more along the lines of CoffeeScript. It bifurcates the landscape even further, but honestly I don't think it can really get any worse than it is now. But at least it will be building on top of sanity and not the lava layer.
Not having to deal with extra debugging layers, lesser debugging tools and additional manual FFI is much more productive than whatever I might gain in syntax/semantics of the "compile-to" language.
Or as difficult as the authors of the code you're using made it.
No - JS is a special beast. Because it's designed from a simple hack on up, by distributed committee, with so many implementations ...
it's inherently problematic.
Foremost - when you say 'JavaScript' what does that even mean? Even different JS versions are implemented slightly differently with some containing features, others not.
It's this tedious, byzantine aspect of JS that makes learning it actually hard, because it's like walking on shifting sand.
At least with Java (and most other languages), there is usually one answer however bad or good, usually you know where you stand.
My point was that you'd be hard pressed to find a popular programming language that does not support those features.
I can think of JS, Go, and Erlang.
The rest, you are stuck interoperating sync and async code. Like having a Twisted/Tokio event loop embedded somewhere in your Python/Rust program and thinking very, very hard about how your blocking calls are not blocking your async runtime, like passing around an I/O thread pool and ensuring it cannot be starved.
I wouldn't be so quick to dismiss it, much less as something that every other language has.
But I have noticed that it's not something you necessarily appreciate until you've written async systems in languages with blocking APIs.
In another comment you point out that Java has promises, so who cares if JS has them. As if the hard part of straddling async/sync ecosystems is whether there exists a concurrency primitive at all.
Even Go programmers should be able to look at their WaitGroup code and have some envy when they see:
Promise.map(things, (thing) => process(thing), { concurrency: 4 })
It's kind of like how the person that seems to have the most negative views of other people is likely to be the person who has least left their hometown -- it's just how humans are.
Op referred to async programming. I'm unaware of any popular programming language that does not support async programming.
> I wouldn't be so quick to dismiss it, much less as something that every other language has.
All languages can play the "no true scotsman" game and claim they are the only one within a myriad of alternative languages. Yet, they all support async programming, either conventional forms or as a nuanced implementation, either through modules or built into the language with the right to reserved keywords and all.
> I think our propensity to miss the light of other languages/ecosystems is a reminder of how little breadth of experience we actually have across the field.
Actually, people who lack experience and understanding tend to grab hold to their only tool of the trade and give it an inflated value just because it happens to be the only thing they do, and thus they see their personal worth as tied to the perceived worth of their tool. Consequently we end up with these futile discussions on how language X or Y is the bestest, most unique technology that nothing even comes close to match.
But yet async programming is supported by all popular programming languages, isn't it?
Some languages picked it up along the way. So in my case, I only first found out about closures in JS, after going through several popular languages, that got closures only later on: Pascal, C++, PHP...
e.g. Java may be adding support for more async stuff, but most of the Java codebases I've worked with won't use it.
for (let i = 0; i != 3; i += 1) {
console.log(i); // i refers to the variable defined below
const i = 0;
}And here is another one, upvar in Tcl.
I clicked in hope I'll get something targeted towards developers that have nothing to do with the javascript "ecosystem" but understand programming concepts, algorithms etc. Is there such a thing?