Я ☞ Primitives ☞ Optional

Aliases: Maybe, Halts | Subtypes: State | Supertype: Unit `S` _

How to get an Optional value:

Some: item `AR_` Optional item
None: Unit `AR_` Optional item
wrap: item `S` Unit `AR_` Optional item
Maybe: item `S` Unit `AR_` Optional item

Useful for early return computations:

Some _ `yo`   Try `ha` Some ===> Some (Some _)
Some _ `yok`  Try `ha` Some ===> Some _
None _ `yok`  Try `ha` Some ===> None _
Some _ `yokl` Try `ha` Some ===> Some (Some _)
None _ `yokl` Try `ha` Some ===> None _
Some _ `yokl` Try `ha` None ===> None _

Can be used as a jointed effect with State.

State _ `JNT` Halts

Could be rewrapped to a Boolean, Progress since it’s a Sum.