ContextQMD
Back to Lo

It Sequencestate

docs/data/it-sequencestate.md

1.53.01.4 KB
Original Source

Empty returns an empty sequence.

go
empty := it.Empty[int]()
var result []int
for item := range empty {
    result = append(result, item)
}
// result is empty []

IsEmpty returns true if the sequence is empty.

go
emptySeq := it.Empty[int]()
notEmptySeq := func(yield func(int) bool) {
    yield(1)
}

fmt.Println(it.IsEmpty(emptySeq))    // true
fmt.Println(it.IsEmpty(notEmptySeq)) // false

IsNotEmpty returns true if the sequence is not empty.

go
emptySeq := it.Empty[int]()
notEmptySeq := func(yield func(int) bool) {
    yield(1)
}

fmt.Println(it.IsNotEmpty(emptySeq))    // false
fmt.Println(it.IsNotEmpty(notEmptySeq)) // true

CoalesceSeq returns the first non-empty sequence.

go
empty1 := it.Empty[int]()
empty2 := it.Empty[int]()
notEmpty := func(yield func(int) bool) {
    yield(1)
    yield(2)
}

result, found := it.CoalesceSeq(empty1, empty2, notEmpty)
// found is true, result is the notEmpty sequence

result2, found2 := it.CoalesceSeq(empty1, empty2)
// found2 is false, result2 is an empty sequence

CoalesceSeqOrEmpty returns the first non-empty sequence.

go
empty1 := it.Empty[int]()
empty2 := it.Empty[int]()
notEmpty := func(yield func(int) bool) {
    yield(1)
    yield(2)
}

result := it.CoalesceSeqOrEmpty(empty1, empty2, notEmpty)
// result is the notEmpty sequence

result2 := it.CoalesceSeqOrEmpty(empty1, empty2)
// result2 is an empty sequence