package main

import (
    "bufio"
    "fmt"
    "strings"
    "os"
    "reflect"
)
const TOKEN string = ":="

func validate(expr string) {
    fmt.Println("var type: ", reflect.TypeOf(expr))
    if strings.Contains(expr, TOKEN) {
        fmt.Println(expr, "contains works")
    } else {
        fmt.Println("error with contains")
    }

    if strings.HasSuffix(expr, TOKEN) {
        fmt.Println(expr, "suffix works")
    } else {
        fmt.Println("error with suffix")
    }
}

func main() {
    var expr2 string
    reader := bufio.NewReader(os.Stdin)
    fmt.Print("type something finished with ':='")
    expr1, _ := reader.ReadString('\n')
    fmt.Scanln(&expr2)

    fmt.Println("validation with reader: ")
    validate(expr1)
    fmt.Println()
    fmt.Println("validation with Scanln: ")
    validate(expr2)
}