closureの演習

exercise.go

package main

import "fmt"

// fibonacci is a function that returns
// a function that returns an int.
func fibonacci() func() int {
    i  := 0
    a0 := 0
    a1 := 0

    return func() int {
        switch i {
        case 0:
            a1 = 0
        case 1:
            a1 = 1
        default:
            j := a1
            a1 = a0 + a1
            a0 = j
        }

        i++
        return a1
    }
}

func main() {
    f := fibonacci()
    for i := 0; i < 10; i++ {
        fmt.Println(i, f())
    }
}