Go match a value by using slices of values as cases with switch statement

Question

I know you can match multiple values with the switch statement by separating values with commas:

func main() {
    value := 5
    switch value{
    case 1,2,3:
        fmt.Println("matches 1,2 or 3")
    case 4,5, 6:
        fmt.Println("matches 4,5 or 6")
    }
}

http://play.golang.org/p/D_2Zp8bW5M

My question is, can you match multiple values with the switch statement by using slice(s) of multiple values as case(s)? I know It can be done by using if else statements and a 'Contains(slice, element)' function, I am just wondering if its possible.

Something like this maybe?:

func main() {
    value := 5

    low := []int{1, 2, 3}
    high := []int{4, 5, 6}

    switch value {
    case low:
        fmt.Println("matches 1,2 or 3")
    case high:
        fmt.Println("matches 4,5 or 6")
    }
}

Answer 1

The best you can get is probably this one:

package main

import "fmt"

func contains(v int, a []int) bool {
    for _, i := range a {
        if i == v {
            return true
        }
    }
    return false
}

func main() {
    first := []int{1, 2, 3}
    second := []int{4, 5, 6}

    value := 5
    switch {
    case contains(value, first):
        fmt.Println("matches first")
    case contains(value, second):
        fmt.Println("matches second")
    }
}

Answer 2

If you have control over the slices, you could just use maps instead:

package main

func main() {
   var (
      value = 5
      low = map[int]bool{1: true, 2: true, 3: true}
      high = map[int]bool{4: true, 5: true, 6: true}
   )
   switch {
   case low[value]:
      println("matches 1,2 or 3")
   case high[value]:
      println("matches 4,5 or 6")
   }
}

or if all the numbers are under 256, you can use bytes:

package main
import "bytes"

func main() {
   var (
      value = []byte{5}
      low = []byte{1, 2, 3}
      high = []byte{4, 5, 6}
   )
   switch {
   case bytes.Contains(low, value):
      println("matches 1,2 or 3")
   case bytes.Contains(high, value):
      println("matches 4,5 or 6")
   }
}