Haskell is our first choice for building production software systems

Post by PietPtr » Mon, Jan 11, 2021, 6:48 PM UTC

414owen wrote: post #259

PietPtr wrote: post #200

Earlier quoted context omitted.

Working with Haskell professionally sounds like a very interesting career path. Could you point to some resources to get better at the production Haskell skills that these companies are looking for? Perhaps gaining experience with projects which use Haskell in a similar way to the companies you mention could help with finding that first Haskell job.

Sure thing. I'm not sure what your current level is, but I can give some general advice for people that happen upon this: --- Haskellers are generally expected to understand most of the typeclassopedia ( https://wiki.haskell.org/Typeclassopedia ), don't worry about learning it all in one go. I had to read this page many times before I grokked most of it. --- Avoid tutorials that overuse analogies. A Monad only adds o…

Post by mehrdadn » Mon, Jan 11, 2021, 7:05 PM UTC

msla wrote: post #179

mehrdadn wrote: post #128

Earlier quoted context omitted.

You're asking for the impossible. What you want is precisely what templates are, but you also want them to not be "templates" for... some bizarre reason. > I can have an array of T, but I can't specify that T is Numeric? Sure you can. If you have C++20 concepts: template concept Numeric = std::integral || std::floating_point ; template T twice(T x) { return x + x; } Or if you're on a C++11 compiler: template typename…

Bah. Leave it to the latest versions of C++ to show me up.

Post by Geminidog » Mon, Jan 11, 2021, 7:37 PM UTC

tome wrote: post #262

Geminidog wrote: post #256

Earlier quoted context omitted.

>You seem to be lumping all side-effects together as equally bad? Never implied anything was bad or good. Just saying that Haskell style programming does not push side effects to the edge. >I don't think you can expect to push everything out to the edges, for example partiality. Of course you can't push everything to the edge, but haskell style programming doesn't attempt to do this. It embraces the side effects and…

> But my argument is this is not often done. I've seen tons of giant IO functions wrapped in do notation. Generally, no big attempt is made to segregate IO or side effects away from pure logic. Everyone just writes a monad and starts using do notation. Yeah, "functional core/imperative shell" or "pushing IO to the edges" is a weird myth. Really the strength of Haskell is "functional core/IO code carefully threaded th…

Post by portal_narlish » Mon, Jan 11, 2021, 7:53 PM UTC

jcelerier wrote: post #2

> Many programmers encounter statically typed languages like Java or C++ and find that the compiler feels like an annoyance. By contrast, Haskell’s static type system, in conjunction with compile-type time checking, acts as an invaluable pair-programming buddy that gives instantaneous feedback during development. the reason they "find that the compiler feels like an annoyance" is because their first exposure to Java…

Post by uryga » Mon, Jan 11, 2021, 8:10 PM UTC

zvrba wrote: post #260

uryga wrote: post #82

Earlier quoted context omitted.

if it has side-effects, it has to be something like Int -> Int -> IO Bool otherwise the type checker won't let you perform any side-effecting operations (btw Haskell's `IO Bool` would be spelled `IO ` in C++/Java syntax)

But is _just reading_ from a database a "side-effect"? It is non-deterministic, but it has no side-effects. So IO jumbles together the two notions.

  do print "a"
     print "b"
 
  -- obviously not the same as
  
  do print "b"
     print "a"

  do a