For a combination between maps and sets, you could...

# kotlin-inject

[evant]

For a combination between maps and sets, you could wire something together but it would be a bit complicated

typealias Foo1 = Foo
typealias Foo2 = Foo

@Provides @IntoSet
fun foo1ForSet1(): Foo1 = ...
@Provides @IntoSet
fun foo2ForSet1(): Foo1 = ...
@Provides @IntoSet
fun foo1ForSet2(): Foo2 = ...
@Provides @IntoSet
fun foo2ForSet2(): Foo2 = ...

@Provides @IntoMap
fun fooSet1(set: Set<Foo1>): Pair<String, Set<Foo>> = "one" to set
@Provides @IntoMap
fun fooSet2(set: Set<Foo2>): Pair<String, Set<Foo>> = "two" to set

[dave08]

I thought of that, but it does seem a bit messy... in the end I opted to make a factory class in this case. This use might be a bit too niche to be in kotlin-inject, I was just hoping it was already there 😉.

[evant]

yeah I think it might be, not sure what the syntax would even look like

[dave08]

I wonder if there's a meaningful error in such a case... (using @IntoMap @IntoSet )... that's one of the problems with annotations, you can't assure the right combinations are being used and what the wrong ones might do...

[evant]

Yeah I believe it could error out if you had both

[evant]

hm, actually that could be valid in theory

fun @Provides @IntoMap @IntoSet fun provideFoo(): Pair<String, Foo> = ...
abstract val fooMap: Map<String, Foo>
abstract val fooSet: Set<Pair<String, Foo>>

not sure if useful in practice...

[dave08]

🙃...

[dave08]

If already, THAT could probably be turned into a Map<String, Set<Foo>>... not so pressing, but if easy to implement, would make that a bit more logical...

[dave08]

Truth is, that if there are multiple on the same key even without the @IntoSet would probably throw... maybe an @IntoMapSet would do both?

fun @Provides @IntoMap fun provideFoo1(): Pair<String, Foo> = "some-key" to Foo1()

fun @Provides @IntoMap fun provideFoo2(): Pair<String, Foo> = "some-key" to Foo2()

[evant]

so actually that won't through heh, it will generate

mapOf(provideFoo1(), provideFoo2())

and the second key would override the first