the arc of software bends towards understanding
What is the biggest possible Haskell program that you could try debugging a space leak in? One very good choice is GHC, weighing in nearly a 100k lines of code (though, thankfully, 25% of that figure is comments.) Today, I’m going to describe one such space leak that I have fixed in GHC. This is […]
Another common thunk leak arises from mapping functions over containers, which do not execute their combining function strictly. The usual fix is to instead use a strict version of the function, ala foldl' or insertWith', or perhaps using a completely strict version of the structure. In today’s post, we’ll look at this situation more closely. […]
This is an addendum to my second example in Anatomy of a thunk leak, in which I’d like to propose another solution to the space leak, involving computing the composition of all of these thunks. This solution is particularly notable because it preserves the denotation of the original function, that is, that f l (undefined, […]
In this post, we discuss the characteristics of a thunk leak, the leak that has come to symbolize the difficulties of “reasoning about space usage” in Haskell. I’ll consider a few examples of this type of leak and argue that these leaks are actually trivial to fix. Rather, the difficulty is when a thunk leak […]
A big thanks to everyone who everyone who sent in space leak specimens. All of the leaks have been inspected and cataloged by our experts, and we are quite pleased to open the doors of the space leak zoo to the public! There are a few different types of space leak here, but they are […]