Feature Request: Generics Template, and I can work on PR

[karambarakat]

I was working on generic template to be used to define many similar schemas:

const result = (error: WhatShouldGoHere) => v.variant("state", [
    v.object({
        state: v.literal("ok"),
        data: v.array(v.string()),
    }),
    v.object({
        state: v.literal("err"),
        err: error,
    }),
]);

const res1 = result(v.string());
const res2 = result(v.null());

But I realized figuring out the exact type of 'WhatShouldGoHere' is a lot of work. If you are interested in implementing a feature like this, I suggest it has a syntax like this, and I can work on a pull request.

const result = v.generic((input) => v.variant("state", [
    v.object({
        state: v.literal("ok"),
        data: v.array(v.string()),
    }),
    v.object({
        state: v.literal("err"),
        err: input,
    }),
]);

[fabian-hiller]

Thank you for creating this issue. Can you try replacing WhatShouldGoHere with v.GenericSchema? You can also use a TS generic the argument to be fully typed-safe. I can share example code later if you are interested.