Elm in Production: 25K Lines Later

Post by dmitriid » Mon, Jul 31, 2017, 11:23 AM UTC

mrkgnao wrote: post #107

dmitriid wrote: post #103

Earlier quoted context omitted.

The problem is basically how to arrive at the "same level" in Haskell and in JS. Basically: what does it take to define (or even to just understand) a type-level DSL in Haskell, and a sufficiently advanced library in Javascript. I can take apart almost any JS library and see/understand how it works. How much type-foo do I need to understand Servant? Or any other sufficiently complex Haskell library (a friend of mine…

I'm pretty sure you'll be able to follow the Servant docs, which are quite nice: https://haskell-servant.readthedocs.io/en/stable/ There are definite advantages, and if you're willing to put in as much work as one, say, unconsciously puts in while setting up JS frameworks, understanding libraries like this is definitely doable. (Without the dissertation.)

  {-# LANGUAGE DataKinds             #-}
  {-# LANGUAGE DeriveGeneric         #-}
  {-# LANGUAGE FlexibleContexts      #-}
  {-# LANGUAGE FlexibleInstances     #-}
  {-# LANGUAGE MultiParamTypeClasses #-}
  {-# LANGUAGE OverloadedStrings     #-}
  {-# LANGUAGE ScopedTypeVariables   #-}
  {-# LANGUAGE TypeFamilies          #-}
  {-# LANGUAGE TypeOperators         #-}
  {-# LANGUAGE UndecidableInstances  #-}

Post by mrkgnao » Mon, Jul 31, 2017, 11:26 AM UTC

dmitriid wrote: post #112

mrkgnao wrote: post #107

Earlier quoted context omitted.

I'm pretty sure you'll be able to follow the Servant docs, which are quite nice: https://haskell-servant.readthedocs.io/en/stable/ There are definite advantages, and if you're willing to put in as much work as one, say, unconsciously puts in while setting up JS frameworks, understanding libraries like this is definitely doable. (Without the dissertation.)

The docs are nice, but they complement the code :) Basically to actually understand what's going on, I'll need to learn DataKinds (at the very least). And just to implement something as simple as BasicAuth, this is what I have to start with ( https://haskell-servant.readthedocs.io/en/stable/tutorial/Au... ): {-# LANGUAGE DataKinds #-} {-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE Flexi…

  {-# LANGUAGE FlexibleContexts      #-}
  {-# LANGUAGE FlexibleInstances     #-}
  {-# LANGUAGE MultiParamTypeClasses #-}
  {-# LANGUAGE TypeOperators         #-}
  {-# LANGUAGE UndecidableInstances  #-}

Post by desireco42 » Mon, Jul 31, 2017, 11:34 AM UTC

enalicho wrote: post #44

dmjio wrote: post #21

If decoding json in Elm is considered hard, I'd recommend checking out miso ( https://github.com/dmjio/miso ), a Haskell re-implementation of the Elm arch. It has access to mature json libraries like aeson for that sort of thing, along with mature lens libraries for updating your model. Here's an example of decoding json with GHC.Generics using typeclasses. https://github.com/dmjio/miso/blob/master/examples/xhr/Main.…

You don't need to switch a whole language because of JSON decoding. There are many tools that exist to aid you write JSON decoders in Elm. The language is not just about the architecture -- you can implement the architecture in any language, as Redux has proven. What people like about Elm is the compiler and design philosophy that radiates through the entire community. Switching to Haskell won't give you that, as the…

Post by dmitriid » Mon, Jul 31, 2017, 11:42 AM UTC

mrkgnao wrote: post #113

dmitriid wrote: post #111

Earlier quoted context omitted.

TIL there's some "idea of a monad". Basically this is (in my mind) what's wrong with Haskell: it's overly concerned with the Platonic ideal. Meanwhile that one page on jargon has shown me that I effortlessly implement any and all of those things daily (and understanding what I'm doing) without the need to understand "an idea". I just use the tool that solves the problem. If someone insists on calling this "monadic co…

It's code reuse for concepts. Wouldn't you agree that reusing intuition about things is good? It's the same as knowing what big-O is instead of just memorizing "bubble sort is slower than insertion sort, insertion sort is sometimes faster than quicksort but usually not", or knowing what concurrency is instead of memorizing the API of a library in your favorite language.

  A monad is a triple (M,unit,⋆) consisting of a type constructor M and two operations of the given 
  polymorphic types. These operations must satisfy three laws given in Section 3.
  
  We will often write expressions in the form
    m ⋆ λa. n

Post by hellofunk » Mon, Jul 31, 2017, 11:48 AM UTC

mjaniczek wrote: post #115

hellofunk wrote: post #104

Earlier quoted context omitted.

I agree with much of your points but a few things to add clarification: While lisps do traditionally provide repl-driven development and you can do this in Clojure, most Clojure devs I know are not actively working right at the repl. If you do like some aspects of repl-like interactivity, Elm does have elm-reactor which has some similarities to Clojurescript's figwheel, though not quite as mature or comprehensive. As…

I believe you can use Google Closure Compiler on Elm JS files with great effect the same as Leiningen uses it on ClojureScript JS files. (Although most people probably use uglifyjs instead.) But of course ClojureScript's JS is generated carefully so as to be better optimizable by Google Closure Compiler, and that's not the case with Elm. IIRC, in version 0.19 Elm will change it's JS so that it's better optimizable by…