一些Go语言的特性

package main

import (
    "fmt"
)

const (
    first = iota
    middle
    last
)

type Bird struct {
    Height int
}

func (b Bird) Talk() (words string) {
    words = "bee"
    return
}

func (b *Bird) Fly(height int) {
    b.Height = height
}

type Duck struct {
    Bird
}

func (this Duck) Talk() (words string) {
    words = "gaga gaga"
    return
}

func (this *Duck) Fly() {
    this.Height = 1
}


func calculate(method string, args ...int) int {
    var result int
    for i := range(args) {
        result += i
        fmt.Println( result, i)
    }
    return result
}

func will_cause_panic() {
    defer func() {
        if r:= recover(); r != nil {
            fmt.Println( "Programe fatal @", r)
        }
    }()

    func() {
        panic("tmp assigned 1")
    }()
}

func main() {
    will_cause_panic()

    fmt.Println("calculaet add",  calculate("add", 1, 2, 3, 4, 5) )

    bird := new(Bird)

    fmt.Println( bird.Talk() )
    bird.Fly(100)
    fmt.Println( bird.Height )
    fmt.Println( first, middle, last)

    duck := new(Duck)
    fmt.Println( duck.Talk() )
    duck.Fly()
    fmt.Println( duck.Height )

    arr := [3]int{1, 2, 3}
    fmt.Println( arr )

    arr[0], arr[2] = arr[2], arr[0]
    fmt.Println( arr )

    for k, v := range arr {
        fmt.Print( k, v)
    }
    for k, v := range(arr) {
        fmt.Print( k, v)
    }

    fmt.Println( arr[1:] )

    arr_by_make := make([]int, 5)
    fmt.Println(arr_by_make)

    m := make(map[string] string)
    m["name"] = "soasme"
    m["github"] = "http://github.com/" + m["name"]
    m["nothing"] = "dummy"
    fmt.Println(m)

    delete(m, "nothing")
    fmt.Println(m)

    _, dummy_ok := m["nothing"]
    if ! dummy_ok {
        fmt.Println("nothing not in m")
    }

}