Shapeless? - Easy!

on YouTube ↗31m

" summary

Shapeless is a Scala generic programming library with about 70 contributors and ~40,000 lines that turns case classes into HList representations via Generic so you can write type-driven algorithms like a compile-time size counter. The demo builds a Delta diff algebra that compares nested fields (addresses inside person) with low-priority implicits to prefer structural generics over primitives, and a Patcher that applies a Delta to produce an updated instance — it compiles and runs.

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" chapters (14)

1. 0:00Shapeless and generic programming
2. 1:13Generic programming benefits
3. 2:39HLists in Shapeless
4. 4:27HList manipulation with type classes
5. 6:38Live demo counting HList elements
6. 9:16Case class ↔ HList conversion
7. 10:44Generic programming use case
8. 12:11Delta type for comparisons
9. 16:30Delta type class implementation
10. 17:12Live demo: comparing case classes
11. 18:39Nested comparisons with Delta
12. 23:35Other Shapeless features
13. 25:00Applying Deltas to modify objects
14. 27:37Q&A

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