or list fusion, but yes Haskell will optimise map x (map y lst) to map (x . y) lst https://stackoverflow.com/questions/38905369/what-is-fusion-in-haskell#:~:te

or list fusion, but yes Haskell will optimise map x (map y lst) to map (x . y) lst https://stackoverflow.com/questions/38905369/what-is-fusion-in-haskell#:~:text=Rewrite%20rules https://stackoverflow.com/questions/38905369/what-is-fusion-...