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A comment on Scala.js for large and complex front end apps [video]. Parent comment

Re:Scala.js for large and complex front end apps [video] by weego on Friday March 18, 2016 @12:57PM (#11313089)
My feeling from a business point of view is: with Scala devs being a) relatively scarce in the market and b) the salary attached to a Scala dev, why would I spend their time getting them to write that's going to end up being JS when a highly skilled JS dev can be found easier and costs less (if you have both already then the relative opportunity cost difference).

Add time for compiling, edge cases, bugs and no matter how awesome it is, I can't see how it ever makes sense outside of a 1 person project.

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Re:Scala.js for large and complex front end apps [video] by lomnakkus on Friday March 18, 2016 @01:28PM (#11313367)
When the compiler eliminates huge classes[1] of bugs you can afford to hire fewer devs and not suffer any loss in quality. Salaries are a huge part of why software development costs as much as it does.

[1] Yes, classes. As in: You can never misspell an object property and have that mistake make it into production (&c for lots of other types of bugs). Plus, you get automatic refactoring you can actually rely on. Now, your JS devs may not appreciate that, but I suspect that's just because they're inexperienced and/or haven't actually worked in a good[2] statically typed language. There's also the fact that we (as humans) unconsciously try to minimize our own mistakes; "oh well, it was just a typo and we fixed it quickly!" and for most of us mistakes tend to fade quickly from memory... thus leading to a very biased view of one's own development practices which doesn't take into account how many mistakes you really make.

[2] I'm going to do a D. F. Wallace here[3].

[3] ... and say that Scala isn't great as languages go[5], but I'll bet you it's a hell of a lot better than any statically typed language your typical JS devs have any experience with[4]. One particular gripe of mine is that they still permit "null", but that's because of Java compatibility. (Oh, how much better Scala could have been without Java compatibility.)

[4] ... which would obviously colour their perception of the trade-offs between static type checking and "verbosity", "bondage & discipline", etc.

[5] It is good, though.

I think that's enough footnotes for now.

EDIT: Sorry, I lied. Added another footnote. Really doing the DFW thing, but in Reel Time(TM).

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Re:Scala.js for large and complex front end apps [video] by nawitus on Friday March 18, 2016 @03:46PM (#11314378)
If static typing is the selling point of Scala.js you might as well use TypeScript, which would be familiar to JavaScript developers.
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Re:Scala.js for large and complex front end apps [video] by lomnakkus on Friday March 18, 2016 @03:55PM (#11314451)
No. Static typing in TS is very very far from what Scala can do[1]. Just as an example: Scala can do type inference (albeit local) which TS cannot do in any meaningful sense. There's a huge difference and you owe it to yourself to try it out for a real project!

[1] My company started out with TS, but after converting about 10% of our app from TS to Scala.JS + scala.js-react we just decided to convert the rest in a mad sprint over a few weeks. It has paid off in spades. We still struggle with the abomination that is CSS and separating styles from components, but it is what it is.

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Re:Scala.js for large and complex front end apps [video] by nawitus on Sunday March 20, 2016 @01:53PM (#11323846)
You're incorrect. TypeScript can do a lot of type inference. I've used TypeScript full-time for about two years, I don't have experience with Scala.js though.
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Re:Scala.js for large and complex front end apps [video] by airless_bar on Tuesday March 22, 2016 @02:13AM (#11334735)
I think most types for which you would care about type inference in Scala can't even be expressed in Typescript ...
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Re:Scala.js for large and complex front end apps [video] by lomnakkus on Tuesday March 22, 2016 @05:13PM (#11340002)
Yeah. HKTs are one particular instance, though even Scala doesn't necessarily do particularly well on those compared to e.g. Haskell (well, GHC, really).

(It seems subtyping and higher-order reasoning just don't mix well. Undecidability abounds, unfortunately. I tend to prefer higher-order reasoning over subtyping.)

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Re:Scala.js for large and complex front end apps [video] by jtwebman on Friday March 18, 2016 @02:51PM (#11313968)
This is only true because after a few years the front-end guys want and probably get to re-write their code for some new design or the latest fizz-bang framework. So they don't have to refactor / maintain 5+ year old code.

I would look at Elm as if it compiles you will not get a runtime error but Elm devs probably are even more scarce then Scala devs.

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Re:Scala.js for large and complex front end apps [video] by djtriptych on Friday March 18, 2016 @01:17PM (#11313272)
Because scala code done well eliminates huge swathes of bug classes that are common in javascript. It may be worth it for "mission-critical" UI, or to rewrite lower-level UI code in stronger semantics.
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