charred abyss
Hi, I'm having trouble creating a map whose keys are a constructor (the class) and values are an instance of said class. Aditionally I also want to require the keys to implement a specific instance.
This is what I tried: (playground link) but it doesn't correctly error if the set value isn't an instance of the key, and when getting it doesn't return an instance of the key, but rather an instance of the interface. I'm not sure what I'm doing wrong here.
midnight sailBOT
amgelo563#0
azure ruin
maps are homogenous, they don't have different mappings for each speciifc key
charred abyss
what could I do in my case then?
it seems that overriding the get method works but it's not really the ideal situation I guess
type ConstructorInstanceMap<C extends Constructor = Constructor> = Omit<Map<C, InstanceType<C>>, 'get'>
& { get<const C extends Constructor = Constructor>(k: C): InstanceType<C> };
yeah, kind of like a service storage
pulsar crown
I need to know how you want to use it to make a suggestion
My first though it something like
class Foo {}
class Bar {}
const services = {
foo: new Foo,
bar: new Bar
}
services.foo
services.bar
But without knowing what you're trying to achieve, can't really see the logic in making it more complicated than this.
charred abyss
I'm making a file system for reading/parsing configuration files for my project, I already have the FileProcessors that do all that for an individual file, and I want to create a "repository" where I can then get those processors from their class, and register them as well dynamically
the easier solution would be to basically just wrap a map, but I'm struggling on the type of said map
pulsar crown
hmm
You could probably use a Map and just don't worry that it's not type checked
Seems unlikely that you can mess up that bit of code
charred abyss
yeah that's fair, also the consumer wouldn't know it actually uses a map
I think I'll just stick to that for now since the alternative to override every method doesn't seem practical lol
pulsar crown
function registerConfig(Class: new () => object) {
map.set(Class, new Class)
}
If you're doing something like this and it's all wrapped in functions, then yeah
floral moth
This works 🙂
class ConstructorMap extends Map<Constructor<MyInterface>, MyInterface> {
constructor() {
super();
}
set<T extends MyInterface>(key: Constructor<T>, value: T) {
return super.set(key, value);
}
}
heady helm
I think I'll just stick to that for now since the alternative to override every ...
Is your consumer actually going to use methods other than get/set/maybe has?
Because signatures like keys, values, entries all have to be changed as well.
Well maybe not keys/values if your underlying Map<K, V> already has matching K/V.
charred abyss
This works 🙂
```ts
class ConstructorMap extends Map<Constructor<MyInterface>, M...
yeah that's pretty much this #1288883259090010122 message which isn't ideal because then I have to override each method