Curry On!
7 HN recommenders · recommended in 9 months, 2015–2023
58:23 · 82K views · Jul 14, 2015
Evan Czaplicki, creator of Elm, talks at Curry On 2015 about user-focused language design. He explains the principles behind Elm and how to make a functional, typed language as approachable as JavaScript.
Recommended as the clearest explanation of Elm's design thinking and of making functional languages mainstream, plus a popular monad explanation clip.
13 comments from Hacker News
> Elm is cute and interesting, but it's type system is less expressive than other languages and lacks features that I consider essential. I'd recommend watching this talk: [0]. Evan talks a lot about the decisions that went into the language, such as not having type classes or other advanced features. He makes a strong case for Elm not as a language-to-rule-them-all, but as a tool for the average programmer, who is more interested in building things than in learning about theory. The myriad language features in Haskell, OCaml, etc. are wonderful to those who understand them, but have not proven to be particularly effective at attracting those who aren't already interested in the languages. In that talk, he really made a strong case as to why Elm is valuable and relevant, even for someone such as myself, a functional programming nerd who loves learning about type theory, abstract algebra, and similar things. Also, I really don't think it's fair to say "The amount of people using Elm right now is a drop in the bucket compared to the amount of people using OCaml (and F#, in more recent years)." OCaml has been around for almost 20 years now, and F# for more than 10. Both have the backing of very large development teams. [0]: this video
Elm creator Evan Czaplicki can, in an elegant and pedagogical way that would feel familiar to at least developers coming from JS: this video from 24:14 until 29:39. Haskell/FP/Math purists would probably balk at the oversimplification. But introducing intimidating concepts by way of such oversimplification (without entirely missing the target) is precisely the point! Beginners just need a very rough and coarse grained overview, so they are able to gain some basic familiarity with the concept. That gives them some already-familiar conceptual knobs to hang further details on, reduces fear, and inspires curiosity to investigate further.
Evan has described a lot of the thinking behind his decisions in this talk: this video The <~ for Signal.map is a good example for a "clever" thing which makes languages hard to read for newbies. It looks like it's part of the syntax and not a function. It's not hard to understand, but it's another thing to learn. I am very happy that things are removed from Elm (or not added in the first place, like type classes) because design is not finished when there is nothing more to add but when there is nothing more to remove.
I like how mpj explains it. Monad - FunFunFunction #21 [LINK] Furthermore, the creator of Elm has a fun explanation too. Evan Czaplicki - Let's be mainstream! User focused design in Elm - Curry On this video More serious computer scientist explains monads in the following. Erik Meijer: Functional Programming [LINK] and here too [LINK]
I'm pretty keen to play with Elm, but it gives me some pause that an app like this (or the demo at [LINK] ) results in... 11k lines of Javascript. Nevertheless, these talks got me bulled up on Elm: [LINK] (Richard Feldman, collegially, on React -> Elm)</a> / this video (Evan Czaplicki on the motivation for Elm)