What’s so bad about Template Haskell?
It seems that Template Haskell is often viewed by the Haskell community as an unfortunate convenience. It’s hard to put into words exactly … Read more
haskell
How fundamentally different are push-pull and arrowized FRP?
I want to study FRP in Haskell, but it’s a bit difficult to decide on a library to use. Many seem to be … Read more
What does the exclamation mark mean in a Haskell declaration?
I came across the following definition as I try to learn Haskell using a real project to drive it. I don’t understand what … Read more
Abusing the algebra of algebraic data types – why does this work?
The ‘algebraic’ expression for algebraic data types looks very suggestive to someone with a background in mathematics. Let me try to explain what … Read more
What is Weak Head Normal Form?
What does Weak Head Normal Form (WHNF) mean? What does Head Normal form (HNF) and Normal Form (NF) mean? Real World Haskell states: … Read more
Techniques for Tracing Constraints
Here’s the scenario: I’ve written some code with a type signature and GHC complains could not deduce x ~ y for some x … Read more
Good Haskell source to read and learn from [closed]
As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, … Read more
What does the `forall` keyword in Haskell/GHC do?
I’m beginning to understand how the forall keyword is used in so-called “existential types” like this: data ShowBox = forall s. Show s … Read more
Transitivity of Auto-Specialization in GHC
From the docs for GHC 7.6: [Y]ou often don’t even need the SPECIALIZE pragma in the first place. When compiling a module M, … Read more
Why do we need monads?
In my humble opinion the answers to the famous question “What is a monad?”, especially the most voted ones, try to explain what … Read more