Arbitrary subranges of int types were available in Ada for over 40 years via static enforcement via Spark and compilers were able to optimize them nicely.
replyFor a system language I wish Rust would support such things rather than coming with NonZero hacks.
This is called "pattern types" in Rust land, as your parent mentioned, and is exactly the kind of work being talked about.
replyNonZero isn't a hack: it's an example of a common pattern. If pattern types were available today, you'd still want NonZero, as an example of a pretty standard pattern.
The idea is, as always: prove out the specific version, then generalize.
Can it do holes like this?
reply (typep 3 '(or (integer 0 10) (integer 50 100)));; => TYou can use a "subtype predicate" for this: https://learn.adacore.com/courses/Ada_For_The_CPP_Java_Devel...
replyMight be less efficient, no? At least in CL (https://www.lispworks.com/documentation/HyperSpec/Body/t_sat...) this is the case, that static type analysis isn't clever enough to work with predicate based types.
replyI don't know enough about the details to speak to it.
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