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Switching to Elixir

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Re: Switching to Elixir

#131

Post by gampleman »

byhemechi wrote: post #34

I often see people say static typing slows them down and I'd really like to know why that is because for me it's the exact opposite, I really don't like not knowing what format data is in. I'd much rather have to write slightly more verbose code and have a vast number of possible errors caught at compile time instead of having things go wrong in production when someone inputs something a bit weird with nothing so muc…

An important thing to realise is that "static typing" isn't just one thing. The details matter. For instance, type inference is a huge deal in making static typing not painful. Local type inference is something that pretty much all modern languages have adopted, since it makes writing out function bodies much less painful. But I think a lot of static typings bad rep comes from older languages that required lengthy annotations everywhere.

Then you of course have global inference, where you can write code as tersely as in a dynamic language, but still benefit from type checking and add annotations later as a form of documentation for readers.

It also changes the way you code. The best experiences from static typing come IMO from doing type-driven development, where you sketch out your problem first at the type level, then fill out the implementation at the value level. In dynamic languages, you can't program like that. So if you use the same mindset you will find the language limiting.

Re: Switching to Elixir

#132

Post by rkangel »

zoogeny wrote: post #70
throwawaymaths wrote: post #57

Earlier quoted context omitted.

> looking at the magic of LiveView (and LiveBook) What's the magic? I think it's pretty easy to get a correct mental model of everything in livebook maybe excepting exact details of how the diff calculation/data compression works. Even so, you can spy on the websocket messages and get a reasonable picture of what's going on in a pinch. Liveview is incredibly straightforward.

> Liveview is incredibly straightforward. I don't agree. One of the keynotes from the 2023 ElixirConf was Chris McCord (one of the principle developers of LiveView) describing how it is almost 1.0 [1]. One thing that made me laugh a bit was him emphasizing how much Javascript he's had to write (he was referencing the fact that there is an internal community meme that you can achieve such incredible behaviors without…

I suspect that you might be right about using LiveView for things that are traditionally full, rich client side JS apps.

However, it is absolutely awesome for the "slightly javascript" case of a lot of UIs. Two examples, from my work:

Forms with "live" display of validation errors, using one single set of validation on the backend, rather than the duplicated frontend and backend having to match. It's completely trivial to implement with LiveView.

Status displays - We built some development hardware based on a Xilinx Zynq FPGA (FPGA + ARM running Linux) and used LiveView to report a lot of the hardware state - primarily the status of all of the registers. A little fiddling with HTML+CSS for the register widget, but then everything else could not have been easier - render your widget once per register, and rerun that whole thing any time pubsub provides an updated register value.

Re: Switching to Elixir

#133

Post by timwis »

zoogeny wrote: post #56

I have been watching Elixir YouTube videos pretty much every day for the last few weeks. I guess there was an Elixir conference recently and after I watched a couple, YouTube has been sending me a consistent stream of Elixir content. I really want to try out this language. I love the idea of Erlang but the few times I've had to deal with it (an ejabberd chat server was one) I found it to be a bit too quirky. Every vi…

I have found the book _Programming Phoenix LiveView_ to be a great explainer as to what’s going on in liveview. It’s written for people new to Phoenix as well. I’m only halfway through and already building quite a lot with it, and, critically, I reckon I could explain pretty well what’s going on under the hood.

https://pragprog.com/titles/liveview/programming-phoenix-liv...

Re: Switching to Elixir

#134

Post by d3ckard »

wofo wrote: post #107
byhemechi wrote: post #34

I often see people say static typing slows them down and I'd really like to know why that is because for me it's the exact opposite, I really don't like not knowing what format data is in. I'd much rather have to write slightly more verbose code and have a vast number of possible errors caught at compile time instead of having things go wrong in production when someone inputs something a bit weird with nothing so muc…

Lack of proper types is what killed the joy of programming in Elixir for me (I lasted 6 months, hoping I would somehow adapt, but the experience was so miserable that I decided to move on). I simply can't understand how anyone can be productive in a big codebase without the rigor of static typing, but those people exist, so I guess there must be something about our brains that divides us in the dynamic vs static typi…

I believe this as well. I like dynamic typing, because it often feels to me that rigour of static typing is slowing the prototyping phase. Plus overusing types creates a lot of boilerplate. In one of the frontends I've seen adding a boolean field to a form required changing over 10 files - thank you Typescript.

On the other hand, sometimes I feel like it has a lot to do with test writing. I feel people enjoy static typing, because you can get a feedback loop catching certain things without writing any tests. If you do write tests, all the type errors get caught pretty immediately anyway, so I just don't see the benefit.

Personally, the biggest advantage of dynamic typing for me is the ability to skip formalities for a time. If I want a function that can modify any struct with field "val" in (by, let's say, setting it to zero), I can - and I don't have to do multiple definitions, I don't have to define an interface. Just a function and I am done. If I want to skip error handling for now and only code the happy path, I can - and my program will work (and crash on error, but in some cases it's ok).

As the projects get more complex and require higher safety guarantees, static typing helps in ensuring nothing got broken - but nothing beats dynamic typing for prototyping.

Re: Switching to Elixir

#135

Post by spion »

wofo wrote: post #107
byhemechi wrote: post #34

I often see people say static typing slows them down and I'd really like to know why that is because for me it's the exact opposite, I really don't like not knowing what format data is in. I'd much rather have to write slightly more verbose code and have a vast number of possible errors caught at compile time instead of having things go wrong in production when someone inputs something a bit weird with nothing so muc…

Lack of proper types is what killed the joy of programming in Elixir for me (I lasted 6 months, hoping I would somehow adapt, but the experience was so miserable that I decided to move on). I simply can't understand how anyone can be productive in a big codebase without the rigor of static typing, but those people exist, so I guess there must be something about our brains that divides us in the dynamic vs static typi…

I've been on both camps, so I'm hoping I can give some insight.

Lots of statically typed languages are very strict about their types and have too many of them. You have to admit, when you're trying to build something difficult and focus on getting the business logic part of your program right, the last thing you want to be thinking about is e.g. whether you need a String, ByteString, LazyByteString or any of the other types of strings, and which library decided to accept which one. At some level its definitely useful to distinguish between those, and I'm sure a lot of libraries make sensible choices. But initially in the development of the program its just unnecessary busywork that distracts you from the important bits.

In the past, typed languages also made it a bit harder than necessary to create new types, especially in situations where you have serialization and deserialization. And finally, we had to do all this work, and for what? To be unable to prevent the most basic of errors i.e. NullPointerException? You have to admit, it was a hard sell.

A lot of things have changed, however. TypeScript makes it really easy to define types, anywhere - inline on the function in the argument, or right above it. You can pretend the type is correct at deserialization time, or you can use libraries like `zod` to both define a validator and a type in the same syntax - its up to you. Rust similarly has powerful and easy to use tools like serde - structs and enums are easy to define, and easy to attach metadata to them quickly to (de)serialize them accurately. Huge differences from the old world of getters and setters and NPEs.

When using dynamic languages, there are techniques to make things easier. There is the often mentioned testing, which does help verify a large subset of code paths. Lesser known and more subtle technique is coming up with and following a strict naming convention for properties, for example, and to keep things as consistent as you can in general. This is why you often see so much focus in code reviews about conventions, linting and so on.

Nowadays I guess it mostly depends on how good your dynamic language techniques (at the team level) are, as well as what your treshold for type system annoyances is. There are still some annoyances even in the best type systems, but its gotten way, way better.

Re: Switching to Elixir

#137

Post by spion »

d3ckard wrote: post #134
wofo wrote: post #107

Earlier quoted context omitted.

Lack of proper types is what killed the joy of programming in Elixir for me (I lasted 6 months, hoping I would somehow adapt, but the experience was so miserable that I decided to move on). I simply can't understand how anyone can be productive in a big codebase without the rigor of static typing, but those people exist, so I guess there must be something about our brains that divides us in the dynamic vs static typi…

I believe this as well. I like dynamic typing, because it often feels to me that rigour of static typing is slowing the prototyping phase. Plus overusing types creates a lot of boilerplate. In one of the frontends I've seen adding a boolean field to a form required changing over 10 files - thank you Typescript. On the other hand, sometimes I feel like it has a lot to do with test writing. I feel people enjoy static t…

The example is, interestingly possible in TypeScript, at a very cheap cost

  function modifiesValField(struct: {val: number}) {
    struct.val = 0;
  }
Structural types and inline interfaces (or as I like to call them inyourfaces) are pretty cool.

But I do get your point - although type systems have gotten much less annoying, its not like they're perfect.

Re: Switching to Elixir

#138

Post by toolz »

wofo wrote: post #107
byhemechi wrote: post #34

I often see people say static typing slows them down and I'd really like to know why that is because for me it's the exact opposite, I really don't like not knowing what format data is in. I'd much rather have to write slightly more verbose code and have a vast number of possible errors caught at compile time instead of having things go wrong in production when someone inputs something a bit weird with nothing so muc…

Lack of proper types is what killed the joy of programming in Elixir for me (I lasted 6 months, hoping I would somehow adapt, but the experience was so miserable that I decided to move on). I simply can't understand how anyone can be productive in a big codebase without the rigor of static typing, but those people exist, so I guess there must be something about our brains that divides us in the dynamic vs static typi…

I'm firmly in the camp that it's all perception. The studies I've seen aren't what I would consider conclusive, but they certainly suggest there is very little difference in the output and bugs of dynamic vs static languages.

In my experience, static typing seemed to lend itself to poor testing, maybe some sort of belief that static types were good enough to not need tests that can prevent regressions. So from my point of view the static typing is negative value. It prevents such a low value class of bugs while seemingly incentivizing people to be lax with the most important classes of bugs.

Re: Switching to Elixir

#140

Post by tionis »

colesantiago wrote: post #16

Which companies have used Elixir in production, I know Brex used to use Elixir but now used Kotlin and also the Bleacher Report. Are there any more?

Discord uses it for their backend I think. Interestingly WhatsApp's backend is also built on Beam, but using Erlang directly instead.
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