TypeScript reuse type with dynamic argument

Question

Please, tell me, can I do this with ts? I have next source code:

interface FormStore<T> {
  type: T;
}

interface Form<T> extends FormStore<T> {
  email: T;
  phone: T;
  password: T;
}

interface FormState<R> {
  form: Form<string>;
  validate: Form<boolean>;
}

I want to reuse type FormState<R> and create new with argument. It something looks like replace Form on R:

// This example doesn't work, just only for example
interface FormState<R> {
  form: R<string>;
  validate: R<boolean>;
}

// another file
FormState<CustomForm>

R<string> it will not work. TS does not support higher kinded types — captain-yossarian from Ukraine
– captain-yossarian from Ukraine, Commented Oct 2, 2021 at 19:50
@captain-yossarian yes, and because I ask: how do it? I showed plan, implementation can be any — reznikovkg
– reznikovkg, Commented Oct 2, 2021 at 19:53
Does this approach work for you? Without true higher-kinded types in TypeScript, you can only simulate them via something like a registry. Anytime you create a new type you want to use like this, you need to add it to the registry. If that approach works for you I can write up an answer; if not, please edit the code to show failed use cases. — jcalz
– jcalz, Commented Oct 2, 2021 at 20:39
@reznikovkg When you say "for now" does that mean you're waiting for other suggestions? I'm trying to decide whether to write up an answer for you. — jcalz
– jcalz, Commented Oct 2, 2021 at 21:22

T.D. Stoneheart · Accepted Answer · 2021-10-03 13:57:26Z

1

From your original declaration, this is the best I can do for now. If you don't make set a default type parameter for FormStore & Form, you will have to explicitly use type FormStateF = FormState<Form<unknown>>;, which is awkward.

interface FormStore<T = unknown> {
  type: T;
}

interface Form<T = unknown> extends FormStore<T> {
  email: T;
  phone: T;
  password: T;
}

interface FormState<R> {
  form: { [x in keyof R]: string };
  validate: { [x in keyof R]: boolean };
}

type FormStateF = FormState<Form>;

answered Oct 3, 2021 at 13:57

T.D. Stoneheart

9365 silver badges7 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

TypeScript reuse type with dynamic argument

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related