The magic of Functional Programming is that you can write the verbs before the nouns.
You have so little commitment to what the data structures are, that it doesn’t get in the way.
Today I find myself mapping across and diff-ing lists of arbitrary ad-hoc dictionaries and tuples.
Had I sat down and had to invent / write methods in terms of classes or Haskell’s parameterized types I’d never have thought of these ad-hoc collections as types to define methods on or even to define functions in terms of.
But as it is, mid-function, I can just decide that what I need is to put them into a collection and process this collection in some way.