Zippers
summary
Explains concrete zipper shapes (for a list: left-list, focus, right-list; for a multiway tree: sibling lists, parent context, children) and shows zippers implementable as comonads so you can duplicate and filter all focused positions. Demonstrates real uses: JSON traversal/parsing with backtracking, window focus in XMonad, a breadth‑first tree walk, and a Hackage library called zippers that generates zipper types. States the punchline clearly: the derivative of a data structure is its zipper.
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chapters (8)
- 0:00Start
- 5:05List Zipper
- 7:28Multi-Way Tree
- 8:10Zipper for a Multi-Way Tree
- 15:57Lenses
- 23:14Differentiation
- 30:10Zippers Having Context
- 33:47Function Invocation Is Exponentiation
