some notes wrt foldl vs foldr
fix ambiguous reverse call
foldr tests
POD/notes wrt foldr
swap foldr args to match haskell behavior
POD
Merge branch 'better-folds'

* better-folds:
  POD
  swap foldr args to match haskell behavior
  POD/notes wrt foldr
  foldr tests
  fix ambiguous reverse call
  some notes wrt foldl vs foldr