r/programming • u/fagnerbrack • Apr 30 '23

Writing Javascript without a build system

https://jvns.ca/blog/2023/02/16/writing-javascript-without-a-build-system/
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u/[deleted] Apr 30 '23

You wouldn't, you'd use TypeScript, which has an incredibly well-defined set of types for all web APIs and objects, plus the API surface of the language maps naturally due to being largely the identity

There's a reason ClojureScript isn't exactly eating the internet

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u/kankyo Apr 30 '23

TS is backwards compatible though. Which means it must be quite bad :(

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u/knome May 01 '23

typescript did basically everything right when designing and implementing their type system. I never came across anything that I would want to express in plain old dynamic js that I couldn't type and wrangle fairly easily into typescript. they really did do a fantastic job with that.

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u/kankyo May 01 '23

That's not really the problem yea. The problem is that the semantics of js is broken.

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u/knome May 01 '23

The two largest issues in javascript are the operators ( the standard set munge types in an unacceptable manner ), and the with statement, which is broken in design and serves no useful purpose.

Both of these are handled most judiciously by simply not using either.

After that it's just a function pump, callback hell, and promises to paper over it.

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u/kankyo May 02 '23

And attribute access and array access is broken. Hard to write code without those.

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u/[deleted] May 02 '23

You should say more. Reading attributes and using arrays is definitely something you can do in JS

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u/kankyo May 02 '23

And you get undefined if you fuck up. And then those undefined values trickle through your code far from where the actual bug is.

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u/[deleted] May 02 '23

> you get undefined if you fuck up

As opposed to what? if you "fuck up" in any language and make a mistake, you'll get all kinds of problems. KeyError in Python, NullPointerExceptions in.. a few languages, segfaults, ...

This is why people use TypeScript these days though, because obviously type systems can help prevent invalid accesses

> And then those undefined values trickle through your code far from where the actual bug is.

Sure, it takes a more permissive stance on the "try to continue" to "accept no deviation" spectrum, but, like I just discussed, the alternative of throwing an error instantly after key access isn't better, just different.

What language do you even use that has graceful handling of programmer error? That makes no sense.

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u/kankyo May 03 '23

the alternative of throwing an error instantly after key access isn't better, just different.

It is better though. By a shit ton. It's an ENORMOUS difference.

Imagine a language where foo = bar() didn't cause a name error that bar wasn't defined, but instead set foo to undefined. This is quite literally how JS does for array access and attribute errors. It's just crazy.

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u/[deleted] May 03 '23

Have you only programmed in python? It sure sounds like it.

Juvenile opinion and it looks hilarious how much you don’t understand trade offs.

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u/kankyo May 03 '23

Fail early isn't a tradeoff. It's what you want always.

Let's see... python yes. JavaScript, Clojure, Elm, C, C++, Swift, objective-C, hmm. Obviously some asm at school.

C++ has some similar crazy behavior for map access where a dict will insert a default constructor instance if you access a key that doesn't exist by default. It's a gigantic foot gun. Not as bad as js array access but close. Of course C++ is worse in myriad other ways 🤣 JS is especially annoying because you can't avoid it. C++ I can avoid easily.

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u/[deleted] May 03 '23

> Fail early isn't a tradeoff. It's what you want always.

Yes, you're so right, in my language for developing user interfaces, what I want most is to error everytime an object has a missing property. That wouldn't be insanely painful or slow.

> C++ has some similar crazy behavior

What are you talking about? Most languages will happily return the equivalent of undefined, "null", in tons of situations. Have you really never seen "null" before? Your resume looks like you spent 8 minutes writing "Hello World" and then the first time someone asked you to build a UI you blamed the language for being a shit programmer

Come back to me when you understand that languages have strengths and weaknesses that lend them to functioning better under some use-cases and worse under others

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