Variadic tuple-like function arguments

[sick gazelle]

Hi there,

I'm trying to implement a type-safe version of a vararg function whose arguments are defined in a specific order.

So far I came to the following type declaration:

type PairArgs<L, R> = [L, R, ...PairArgs<L, R>[]];

function foo(arg1: string, ...rest: PairArgs<string, number>);

// Usage:
foo("arg1", "one", 1, "two", 2, "three", 3);

But this only solves the problem for paired arguments (let's call it TupleOfTwo).

Now, I want to introduce a generic version of it (TupleOfN), so I'm trying this:

type TupleArgs<Types extends unknown[]> = [...Types, ...TupleArgs<Types>[]];

but it doesn't work (Type alias TupleArgs circularly references itself.

Is there any way to do a generic N-ary version of such a tuple?

[noble jolt]

FWIW i think usage of foo would be this instead of what you wrote:

foo("arg1", "one", 1, ["two", 2], ["three", 3])

you can do the same with TupleArgs like so:

type TupleArgs<Types extends unknown[]> = [...Types, ...Types[]];

declare function bar(arg1: string, ...rest: TupleArgs<[string, number, boolean]>): void;
bar("arg1", "one", 1, true, ["two", 2, true])

[sick gazelle]

Oh, you're right! I was mistaken about this. And I need something like:

foo("arg1", "one", 1, "two", 2, "three", 3); // repeatable `string, number` pattern

Is there any way to constrain a vararg function with a plain repeatable pattern of argument types?

foo(string, number, string, number, string, number, ...)

[dense flax]

https://stackoverflow.com/questions/76158662/is-it-possible-to-have-rest-parameters-with-repeating-types/76160287#76160287

[sick gazelle]

Exactly what I was looking for! Thank you!

[dense flax]

shouldnt jcalz be the one that gets the