A - The raw type of the value that this key maps to inside an HMapB - The mapped type of the value that this key maps to inside an HMappublic interface TypeSafeKey<A,B> extends Iso.Simple<A,B>
HMaps. Additionally, every TypeSafeKey is an
Iso from the type the value is stored as to the type it's viewed and set as (on the way in / on the way out).
This allows multiple keys to map to the same value, but to view the value as different types.
This is intentionally an interface so user-defined implementations are possible; however, it's important to note
that all hopes of type-safety hinge on equality being implemented such that no two TypeSafeKeys with
differing value-type parameters may be considered equal. Reference equality is used here as the default, as that is
sufficient.
| Modifier and Type | Interface and Description |
|---|---|
static interface |
TypeSafeKey.Simple<A>
|
| Modifier and Type | Method and Description |
|---|---|
default <C> TypeSafeKey<A,C> |
andThen(Iso.Simple<B,C> f)
Left-to-right composition of this
TypeSafeKey with some other Iso. |
default <U> TypeSafeKey<A,B> |
discardR(Applicative<U,Iso<A,?,B,B>> appB)
Sequence both this
Applicative and appB, discarding appB's result and
returning this Applicative. |
static <A> TypeSafeKey.Simple<A> |
typeSafeKey()
Static factory method for creating a simple type-safe key
|
adapt, andThen, compose, compose, mirror, toLensandThen, compose, contraMap, diMap, diMapL, diMapR, discardL, flatMap, fmap, iso, iso, mapA, mapB, mapS, mapT, pure, pureIso, simpleIso, trampolineM, unIso, zipadaptapply, monomorphize, optic, reframedefault <U> TypeSafeKey<A,B> discardR(Applicative<U,Iso<A,?,B,B>> appB)
Iso.SimpleApplicative and appB, discarding appB's result and
returning this Applicative. This is generally useful for sequentially performing side-effects.discardR in interface Applicative<A,Iso<A,?,B,B>>discardR in interface Iso<A,A,B,B>discardR in interface Iso.Simple<A,B>discardR in interface Monad<A,Iso<A,?,B,B>>discardR in interface MonadRec<A,Iso<A,?,B,B>>U - the type of appB's parameterappB - the other Applicativedefault <C> TypeSafeKey<A,C> andThen(Iso.Simple<B,C> f)
TypeSafeKey with some other Iso. Because the first parameter
fundamentally represents an already stored value type, this is the only composition that is possible for
TypeSafeKey, which is why only this (and not Iso.compose(Optic)) is overridden.
Particularly of note is the fact that values stored at this key are still stored as their original manifest
type, and are not duplicated - which is to say, putting a value at a key, yielding a new key via composition,
and putting a new value at the new key still only results in a single entry in the HMap. Additionally,
all previous keys involved in the new key's composition are still able to resolve the value in their native type.
andThen in interface Iso.Simple<A,B>C - the new value typef - the other simple isoTypeSafeKeystatic <A> TypeSafeKey.Simple<A> typeSafeKey()
A - the type of value stored at this key