go_workshop/chapter_04/activity_4.03/main.go

package main

import (
  "fmt"
  "os"
  "strings"
)

type locale struct {
  language string
  region   string
}

func getLocales() map[locale]struct{} {

  supportedLocales := make(map[locale]struct{}, 5)
  supportedLocales[locale{"en", "US"}] = struct{}{}
  supportedLocales[locale{"en", "CN"}] = struct{}{}
  supportedLocales[locale{"fr", "CN"}] = struct{}{}
  supportedLocales[locale{"fr", "FR"}] = struct{}{}
  supportedLocales[locale{"ru", "RU"}] = struct{}{}
  return supportedLocales

}

func localExists(l locale) bool {

  _, exists := getLocales()[l]
  return exists

}

func main() {

  if len(os.Args) != 2 {
    fmt.Println("No locale passed")
    os.Exit(1)
  }

  localeParts := strings.Split(os.Args[1], "_")
  if len(localeParts) != 2 {
    fmt.Printf("Invalid locale passed: %v\n", os.Args[1])
    os.Exit(1)
  }

  passedLocale := locale{
    language: localeParts[0],
    region:   localeParts[1],
  }

  if !localExists(passedLocale) {
    fmt.Printf("Locale not supported: %v\n", os.Args[1])
    os.Exit(1)
  }
  fmt.Println("Locale passed is supported")

}