Golang：函数返回参数错误

The following code gives:

runtime.main: call to external function main.main
runtime.main: main.main: not defined
runtime.main: undefined: main.main

I messed up with the return argument, but why?

Requesting:

fmt.Println( reflect.TypeOf(l)) 

gives *ldap.Conn as type

The code works without trying to return the object

package main

import (
    "fmt"
    "log"

    "gopkg.in/ldap.v2"
)


var Ldap1 = "10.0.0.1"
var Lport1 = 389
var Prpl1 = "cn=admin,dc=Example,dc=com"
var Pass1 = "password"

func Bindldap(ldaphost string, port int, principal string, password string) *ldap.Conn {

    l, err := ldap.Dial("tcp", fmt.Sprintf("%s:%d", ldaphost, port))
    if err != nil {
        log.Fatal(err)
    }
    defer l.Close()

    err = l.Bind(principal, password)
    if err != nil {
        log.Fatal(err)
    }
    return l
}

func Main() {
    a := Bindldap(Ldap1, Lport1, Prpl1, Pass1)
    //do something with a
}

You error messages are telling you it's looking for a function called main in your main package. You called your entry point Main (Note the caps). Try this:

func main() {
    a := Bindldap(Ldap1, Lport1, Prpl1, Pass1)
    //do something with a
}