lo/docs/data/core-groupbyerr.md

name, slug, sourceRef, category, subCategory, playUrl, signatures, variantHelpers, similarHelpers, position

name	slug	sourceRef	category	subCategory	playUrl	signatures	variantHelpers	similarHelpers	position
GroupByErr	groupbyerr	slice.go#L279	core	slice	https://go.dev/play/p/BzKPcY3AdX2	func GroupByErr[T any, U comparable, Slice ~[]T](collection Slice, iteratee func(item T) (U, error)) (map[U]Slice, error)	core#slice#groupbyerr	core#slice#groupby core#slice#groupbymap core#slice#partitionby core#slice#keyby parallel#slice#groupby	121

Groups elements by a key computed from each element using an iteratee that can return an error. Stops iteration immediately when an error is encountered. The result is a map keyed by the group key with slices of original elements.

// Error case - stops on first error
result, err := lo.GroupByErr([]int{0, 1, 2, 3, 4, 5}, func(i int) (int, error) {
    if i == 3 {
        return 0, fmt.Errorf("number 3 is not allowed")
    }
    return i % 3, nil
})
// map[int][]int(nil), error("number 3 is not allowed")

// Success case
result, err := lo.GroupByErr([]int{0, 1, 2, 3, 4, 5}, func(i int) (int, error) {
    return i % 3, nil
})
// map[int][]int{0: {0, 3}, 1: {1, 4}, 2: {2, 5}}, nil