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Core Reduceerr

docs/data/core-reduceerr.md

1.53.0631 B
Original Source

Reduces a collection to a single value by accumulating results of an accumulator function that can return an error. Stops iteration immediately when an error is encountered.

go
// Error case - stops on first error
result, err := lo.ReduceErr([]int{1, 2, 3, 4}, func(agg int, item int, _ int) (int, error) {
    if item == 3 {
        return 0, fmt.Errorf("number 3 is not allowed")
    }
    return agg + item, nil
}, 0)
// 0, error("number 3 is not allowed")
go
// Success case
result, err := lo.ReduceErr([]int{1, 2, 3, 4}, func(agg int, item int, _ int) (int, error) {
    return agg + item, nil
}, 0)
// 10, nil