// Return the nth digit of 1234567891011121314151617....
func Digit(posit int) string {
g := AllDigits()
s := functional.Slice(g, posit, -1)
var r rune
s.Next(&r)
g.Close()
return string(r)
}
func main() {
s := fibonacci()
s = functional.Join(functional.Count(), s)
s = functional.Map(
functional.NewMapper(computeRatio),
s,
&fibWithIndex{0, new(big.Int)})
// Index and ratio from 40th up to 49th fibonacci number.
s = functional.Slice(s, 40, 50)
var results []ratioWithIndex
functional.AppendValues(s, &results)
fmt.Println(results)
}
func main() {
orig := make([]int, 100)
for i := range orig {
orig[i] = i
}
// Return the 10000th up to the 10010th element of the power set of
// {0, 1, .. 99}.
// This entire power set would have 2^100 elements in it!
s := functional.Slice(Power(orig), 10000, 10010)
result := make([]int, len(orig))
for s.Next(&result) {
fmt.Println(result)
}
}