Proposal: Helpers for combine function and tuple

[0x587]

Perhaps we could add some helpers that combine functions and Tuples, so that multi-parameter functions (both input and output) can be easily applied to Maps.

Like This

package main

import "github.com/samber/lo"

func f21(a, b int) int {
	return a + b
}

func f22(a, b int) (int, int) {
	return a, b
}

func TupleFun21[A any, B any, R any](f func(A, B) R) func(lo.Tuple2[A, B]) R {
	return func(tuple lo.Tuple2[A, B]) R {
		a := f(tuple.A, tuple.B)
		return a
	}
}

func TupleFun22[A any, B any, R1 any, R2 any](f func(A, B) (R1, R2)) func(lo.Tuple2[A, B]) lo.Tuple2[R1, R2] {
	return func(tuple lo.Tuple2[A, B]) lo.Tuple2[R1, R2] {
		a, b := f(tuple.A, tuple.B)
		return lo.Tuple2[R1, R2]{A: a, B: b}
	}
}

func FakeIndex[A any, R any](f func(A) R) func(A, int) R {
	return func(a A, _ int) R {
		return f(a)
	}
}

func main() {
	data := []lo.Tuple2[int, int]{
		{1, 2},
		{3, 4},
		{5, 6},
	}
	lo.Map(data, FakeIndex(TupleFun21(f21)))
	lo.Map(data, FakeIndex(TupleFun22(f22)))
}

[0x587]

I think if this feature is implemented, we can write fewer anonymous functions just for repeated parameter conversion.

[samber]

I suppose a Map2...MapX(a A, b B, ...x X) R would do the job.

If I understand your needs, returning a tuple2 is like returning a single value.

[0x587]

oh yes your solution is possible.
In most cases, our function will return (val, err). When an error occurs, we want to stop or ignore the process. If only have Map2 is difficult to apply to this situation.