At the basic level, there’s not much difference, but they’re still there. Haskell describes functions or values defined in a typeclass as ‘methods’, just as traits describe OOP methods in the objects they enclose. However, Haskell deals with these differently, treating them as individual values rather than pinning them to an object as OOP would … Read more
“Integer” is an arbitrary precision type: it will hold any number no matter how big, up to the limit of your machine’s memory…. This means you never have arithmetic overflows. On the other hand it also means your arithmetic is relatively slow. Lisp users may recognise the “bignum” type here. “Int” is the more common … Read more
Before I answer the main question, I’m going to try to define a bit more precisely what it would mean to write code in Haskell or Idris and compile it to run on an Ethereum-like blockchain. Idris is probably a better fit for this, but I’m going to use Haskell because that’s what I’m familiar … Read more
GHC Core is the System FC language into which all Haskell is translated. The (approximate) grammar for Core is given by: Core is closely related to the simpler and better known System F. All transformations GHC does on the Core level are type-preserving refactorings of this Core representation, to improve performance. And, not so well … Read more
Here is how I pronounce them: >>= bind >> then *> then -> to a -> b: a to b <- bind (as it desugars to >>=) <$> (f)map <$ map-replace by 0 <$ f: “f map-replace by 0″ <*> ap(ply) (as it is the same as Control.Monad.ap) $ (none, just as ” ” [whitespace]) … Read more
I don’t see any published version of syntactic whose signature for sugarSym uses those exact type names, so I’ll be using the development branch at commit 8cfd02^, the last version which still used those names. So, why does GHC complain about the fi in your type signature but not the one for sugarSym? The documentation … Read more
Great question! There are several key differences. Representation A newtype guarantees that your data will have exactly the same representation at runtime, as the type that you wrap. While data declares a brand new data structure at runtime. So the key point here is that the construct for the newtype is guaranteed to be erased … Read more
How you do it is by first getting a Haskell compiler which can target C with the android NDK which comes with a GCC port for ARM architectures. JHC can trivially do this with a very small inf style file which describes the platform (word size, c-compiler, etc) I’ve done this with the Wii homebrew … Read more
Ok, so having watched a little of the node.js presentation that @gawi pointed me at, I can say a bit more about how Haskell compares to node.js. In the presentation, Ryan describes some of the benefits of Green Threads, but then goes on to say that he doesn’t find the lack of a thread abstraction … Read more
A type constructor which is not a Functor: newtype T a = T (a -> Int) You can make a contravariant functor out of it, but not a (covariant) functor. Try writing fmap and you’ll fail. Note that the contravariant functor version is reversed: fmap :: Functor f => (a -> b) -> f a … Read more