[Go] Higher-order function combo.

package main

// filter is declared as above.

// apply is declared as above.

// reduce is declared as above.

func main() {
    in := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

    temp := filter(in, func(n int) bool { return n%2 != 0 })
    temp = apply(temp, func(n int) int { return n * n })
    out := reduce(temp, func(a int, b int) int { return a + b })

    if !(out == (1*1)+(3*3)+(5*5)+(7*7)+(9*9)) {
        log.Fatal("Wrong value")
    }
}