You’re Wrong About Functional Programming’s ‘Useless’ Math. Sheaves Are the Killer App.
Sheaves, a concept from algebraic geometry, provide a mathematical guarantee that local data patches that agree on overlaps automatically glue into a coherent global state. In Haskell, this can be enforced at compile time, eliminating entire classes of state management bugs. This article reveals why the most esoteric math is actually the most practical tool for functional programmers.