What optimizations can GHC be expected to perform reliably?
GHC has a lot of optimizations that it can perform, but I don’t know what they all are, nor how likely they are … Read more
ghc
Reading GHC Core
Core is GHC’s intermediate language. Reading Core can help you better understand the performance of your program. Someone asked me for documentation or … Read more
When is -XAllowAmbiguousTypes appropriate?
I’ve recently posted a question about syntactic-2.0 regarding the definition of share. I’ve had this working in GHC 7.6: {-# LANGUAGE GADTs, TypeOperators, … Read more
Why is Haskell (GHC) so darn fast?
Haskell (with the GHC compiler) is a lot faster than you’d expect. Used correctly, it can get close-ish to low-level languages. (A favorite … 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
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