Tag
Type members
Classlikes
Value members
Concrete methods
subst specialized to Id.
subst specialized to Id.
- Todo
According to Miles, @specialized doesn't help here. Maybe manually specialize.
Variants of apply, subst, and unsubst that require
specifying the tag type but are more likely to infer the other
type parameters.
Variants of apply, subst, and unsubst that require
specifying the tag type but are more likely to infer the other
type parameters.
Add a tag T to A.
Add a tag T to A.
NB: It is unsafe to subst or unsubst a tag in an F that is
sensitive to the A type within. For example, if F is a
GADT, rather than a normal ADT, it is probably unsafe. For
"normal" types like List and function types, it is safe. More
broadly, if it is possible to write a ''legal''
scalaz.InvariantFunctor over the parameter, subst of that
parameter is safe.
We do not have a
type role
system in Scala with which to declare the exact situations under
which subst is safe. If we did, we would declare that subst
is safe if and only if the parameter has "representational" or
"phantom" role.