The Power of Optics

on YouTube ↗13m

" summary

Shows concrete Haskell code using the Haskell lens package and Template Haskell-generated makeLenses to get, set and modify deeply nested records, plus hand-built lenses for tuples. Demonstrates lens composition to produce single-focus setters/getters, infix operators that mimic imperative chaining, and examples that translate several state updates into one composed expression. Mentions implementations like van Laarhoven and profunctor optics and posts slides for followup.

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" chapters (15)

1. 0:00Start
2. 0:34The Power of Optics
3. 0:50Agenda
4. 1:56Setup
5. 2:14Getters
6. 3:09Real-World Example
7. 4:03Comparison (Haskell)
8. 4:18Comparison (C#)
9. 4:29Creation
10. 7:09Lens Composition
11. 8:15Custom Lenses
12. 9:08C#- Haskell (With Lenses!)
13. 11:08Operators
14. 11:46Chaining
15. 12:19Next Steps

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