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It Reduce

docs/data/it-reduce.md

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Original Source

Reduces a collection to a single accumulated value by applying an accumulator function to each element starting with an initial value.

Reduce

go
seq := func(yield func(int) bool) {
    _ = yield(1)
    _ = yield(2)
    _ = yield(3)
    _ = yield(4)
}
sum := it.Reduce(seq, func(acc int, item int) int {
    return acc + item
}, 0)
// sum == 10
go
seq := func(yield func(string) bool) {
    _ = yield("hello")
    _ = yield("world")
}
concat := it.Reduce(seq, func(acc string, item string) string {
    return acc + " " + item
}, "")
// concat == " hello world"

ReduceI

Reduces a collection to a single value by iterating through elements and applying an accumulator function that includes the index.

go
result := it.ReduceI(it.Range(1, 5), func(agg int, item int, index int) int {
    return agg + item*index
}, 0)
// 20 (0*0 + 1*1 + 2*2 + 3*3)