Golang: embedding pointer anonymous members

embedding_polymorphism.go

package main

import (
        "fmt"
)

type Mammal struct {
        Lung string
}

type Fish struct {
        Gills string
}

type Amphibian struct {
        Mammal
        Fish
        Name string
}

func main() {
        salamandar := Amphibian{}
        salamandar.Name = "Salamandar"
        fmt.Print(salamandar.Name + " ")

        salamandar.Lung = "Lung"
        fmt.Print("has " + salamandar.Lung)

        salamandar.Gills = "Gills"
        fmt.Println(" and " + salamandar.Gills)

        lion := salamandar.Mammal
        fmt.Println("Lion has a " + lion.Lung)
}

embedding_polymorphism_wrong.go

package main

import (
        "fmt"
)

type Mammal struct {
        Lung string
}

type Fish struct {
        Gills string
}

type Amphibian struct {
        Mammal
        Fish
        Name string
}

func main() {
        salamander := Amphibian{}
        salamander.Name = "salamander"
        fmt.Print(salamander.Name + " ")

        salamander.Lung = "Lung"
        fmt.Print("has " + salamander.Lung)

        salamander.Gills = "Gills"
        fmt.Println(" and " + salamander.Gills)

        nick := salamander.(Mammal)
        fmt.Println("Nick has a " + nick.Lung)
}

inheritance.go

package main

import (
        "fmt"
)

type Mammal struct {
        Lung string
}

type Fish struct {
        Gills string
}

type Amphibian struct {
        Mammal
        Fish
        Name string
}

func main() {
        salamander := new(Amphibian)
        salamander.Name = "salamander"
        fmt.Print(salamander.Name + " ")

        salamander.Lung = "Lung"
        fmt.Print("has " + salamander.Lung)

        salamander.Gills = "Gills"
        fmt.Println(" and " + salamander.Gills)
}

inheritance_ambiguity.go

package main

import (
        "fmt"
)

type Mammal struct {
        Lung string
        Lips string
}

type Fish struct {
        Gills string
        Lips string
}

type Amphibian struct {
        Mammal
        Fish
        Name string
}

func main() {
        salamander := new(Amphibian)
        salamander.Name = "salamander"
        fmt.Print(salamander.Name + " ")

        salamander.Lung = "Lung"
        fmt.Print("has " + salamander.Lung)

        salamander.Gills = "Gills"
        fmt.Println(" and " + salamander.Gills)

        salamander.Mammal.Lips = "Mammal lips"
        salamander.Fish.Lips = "Fish lips"
        fmt.Println(salamander.Name + " has both " + salamander.Mammal.Lips + " and " + salamander.Fish.Lips)
}

inheritance_ambiguity_wrong.go

package main

import (
        "fmt"
)

type Mammal struct {
        Lung string
        Lips string
}

type Fish struct {
        Gills string
        Lips string
}

type Amphibian struct {
        Mammal
        Fish
        Name string
}

func main() {
        salamander := new(Amphibian)
        salamander.Name = "salamander"
        fmt.Print(salamander.Name + " ")

        salamander.Lung = "Lung"
        fmt.Print("has " + salamander.Lung)

        salamander.Gills = "Gills"
        fmt.Println(" and " + salamander.Gills)

        salamander.Lips = "lips"
        mt.Println(salamander.Name + " has " + salamander.Lips)
}

pointer_embedding.go

package main

import (
        "fmt"
)

type Mammal struct {
        Lung string
}

type Fish struct {
        Gills string
}

type Amphibian struct {
        *Mammal
        *Fish
        Name string
}

func NewAmphibian() *Amphibian {
        ret := new(Amphibian)
        ret.Mammal = new(Mammal)
        ret.Fish = new(Fish)
        return ret
}

func main() {
        salamander := NewAmphibian()
        salamander.Name = "salamander"
        fmt.Print(salamander.Name + " ")

        salamander.Lung = "Lung"
        fmt.Print("has " + salamander.Lung)

        salamander.Gills = "Gills"
        fmt.Println(" and " + salamander.Gills)
}

pointer_embedding_wrong.go

package main

import (
        "fmt"
)

type Mammal struct {
        Lung string
}

type Fish struct {
        Gills string
}

type Amphibian struct {
        *Mammal
        *Fish
        Name string
}

func main() {
        salamander := new(Amphibian)
        salamander.Name = "salamander"
        fmt.Print(salamander.Name + " ")

        salamander.Lung = "Lung"
        fmt.Print("has " + salamander.Lung)

        salamander.Gills = "Gills"
        fmt.Println("and " + salamander.Gills)
}