.. highlight:: go

types1.go
=========

::

    // types1.go

    package main

    import (
        "fmt"
    )

    // Number is a brand new type; it is *not* just a synonym for int.
    // Number has the same representation as an int
    type Number int

    // a function
    func isOdd(n Number) bool {
        return n%2 == 1
    }

    // a method
    func (n Number) isEven() bool {
        return n%2 == 0
    }

    func test1() {
        var n Number = 5
        fmt.Println(n)

        // compiler error: can't assign n to x
        // var x int = n
        // fmt.Println(x)

        if isOdd(n) {
            fmt.Printf("%v is odd\n", n)
        }

        if n.isEven() {
            fmt.Printf("%v is even\n", n)
        }
    } // test1

    // Integer is a brand new type whose underlying representation is the same as
    // an int
    type Integer int

    func test2() {
        var i Integer = 6
        var n Number = 5
        fmt.Println(i, n)

        // The following lines are type errors caught by the compiler
        // i = n
        // n = i

        i = Integer(n) // okay

        fmt.Println(i)
    } // test2

    func main() {
        test1()
        test2()
    } // main