A Non-allocating Option

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Adds a new optional type or_null with constructors This and Null that uses the all-zero bit pattern as a non-allocating None, keeps legacy option unchanged, and implements a kind system separating with-null vs no-null types so nesting or_null or_null is rejected. Prototype typechecker changes land in an OCaml compiler branch, runtime work remains in progress. Practical limits include banning alpha or_null arrays to avoid the flat-float non-separability problem and choosing abstract types to default to no-null to ease inference.

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" chapters (11)

1. 0:00Non-allocating Option intro
2. 1:25Extra allocation in Option
3. 2:08Store values directly
4. 3:51None vs some none
5. 4:53Introducing or null type
6. 6:16Demo: or null
7. 9:28Type inference with or null
8. 12:17Flat float arrays
9. 15:48Banning or null arrays
10. 16:51Implementation status
11. 17:12Q&A