Exploring Polymorphism in Go Language

In object-oriented programming, polymorphism allows objects to exhibit different behaviors based on their class. But in Go, the concept of polymorphism is not implemented in the traditional sense. Let's delve into the reasons behind this and explore how to achieve similar functionality in Go.

Why Go Lacks Traditional Polymorphism

Go is not a traditional object-oriented language. It adopts a different approach by using:

• Composition: Objects composed of other objects or interfaces.
• Interfaces: Contracts that define methods and behaviors for a specific type.

Unlike in object-oriented languages, Go does not support method overriding or virtual methods. This allows Go to maintain a higher level of type safety.

Implementing Polymorphism Using Composition and Interfaces

To achieve polymorphism-like behavior in Go, we can employ the following techniques:

1. Create a Common Interface: Define an interface that represents the common behaviors or methods that you want your derived types to implement.
2. Implement the Interface: Implement the interface's methods in your derived types, each providing its own unique implementation.
3. Use Composition: Compose your derived types using the common interface as a field. This allows you to treat all derived types as instances of the common interface.

Example:

package main

import "fmt"

// Common interface
type Foo interface {
    printFoo()
}

// Derived type with unique implementation
type FooImpl struct{}

func (f FooImpl) printFoo() {
    fmt.Println("Print Foo Impl")
}

// Derived type composed using the common interface
type Bar struct {
    FooImpl
}

// Function returning the common interface
func getFoo() Foo {
    return Bar{}
}

func main() {
    fmt.Println("Hello, playground")
    b := getFoo()
    b.printFoo()
}

In this example, Foo is the common interface, FooImpl is the derived type with its own implementation, and Bar is a derived type composed using FooImpl. The getFoo() function returns an instance of the Foo interface, allowing us to treat different derived types as one interface type.

This approach provides a form of polymorphism in Go by enabling us to handle different derived types as instances of a common interface.