Generalized Dijkstra in Haskell

Read online This years’ Advent of Code has loads of 2D grids, and makes you traverse them all to find paths of various kinds. At some point I had to implement Dijkstra’s algorithm , in Haskell. In trying to make my implementation reusable for the following days, I realized that Dijkstra’s algorithm is actually way more general than I remembered (or was taught)! In short, weights don’t have to be…