Я ☞ Primitives ☞ Progress

Supertype: e `ML` ee

Aliases: Error, Probably

Constructors, they could be switched with not:

  Continue: ee `AR_` Progress e ee
Intrerrupt: e `AR__` Progress e ee
     Error: e `AR__` Progress e ee
     Valid: ee `AR_` Progress e ee
        Ok: ee `AR_` Progress e ee

Useful for computations that could be interrupted by errors:

Valid _ `yo` Valid `AR__` Valid (Valid _)
Valid _ `yok` Try `ha` Valid `AR___` Valid _
Error _ `yok` Try `ha` Valid `AR___` Error _
Valid _ `yok` Try `ha` Error `AR___` Error _

Can be used as a jointed effect with State.

State `JNT` Error

Could be rewrapped to a Boolean, Optional.