Re: [Chicken-users] permissive checking of sum types

[Evan Hanson]

Hi David,

Sorry for the slow response, but I'd just like to confirm what it seems
you've already intuited about CHICKEN's type system.

Simply put, CHICKEN's type-directed compilation pass will only optimise
a program when it's *certain* that a given type is correct, and it will
only issue a warning when it's *certain* that a given type is incorrect.
In your example, the type of `value4` may or may not be incorrect, so
nothing is done.

It sounds like you're expecting a much more strict interpretation of
type annotations, but that's not how CHICKEN currently works. It is, as
you say, permissive in its treatment of type annotations.

Cheers,

Evan