Golang has no generics

As a modern programming language, Golang is widely used in high-concurrency and high-performance scenarios such as cloud computing, big data, and blockchain. However, one of the biggest features of Golang is the lack of generics. This article will discuss the reasons and solutions for Golang’s lack of generics from the aspects of Golang’s implementation of mandatory type safety, and how Golang develops without generics.

1. The reason why Golang does not have generics

Generics are a function in programming languages. It allows us to define some common classes, functions or methods, making us more concise. , handle data types efficiently. However, Golang was not designed to implement generics from the beginning. Why is this?

1. Initial Goals

Golang’s creators, Rob Pike, Ken Thompson, and Robert Griesemer, designed Golang primarily with concurrency and network communication on Google servers in mind. s application. In this application, the data structures are relatively simple, and the code requires only a few generic parameters. Therefore, the original intention of Golang did not make generics a required language feature.

2. Simplified type system

The designers of Golang believe that generics will increase the complexity of the language and the difficulty of learning. Golang's type system is very simple, relatively straightforward and easy to understand both in terms of syntax and implementation. If generics are introduced, it will increase the complexity of the language because more complex type hierarchies and type inference mechanisms need to be dealt with. In order to maintain the simplicity and ease of use of the language, Golang has developed a programming model that enforces type safety, which can prevent many errors and make assembly more intuitive for programmers.

3. Simplicity and performance

The designers of Golang also want to make Golang have efficient computing performance, including fast compilation and running speed. When Golang was designed, they believed that compiler analysis of generic code could lead to a significant increase in compilation time. In addition, when executing, generic code requires additional running overhead such as dynamic memory allocation and type conversion operations, which will cause the program to run slower. Therefore, removing generics can make Golang more efficient.

2. Golang uses mandatory type safety implementation

Golang does not have generics, so how to avoid type confusion? Golang's solution is to use enforced type safety, ensuring correct types through static type checking and type inference, and preventing runtime type errors.

In terms of static type checking, Golang will check the types and usage of symbols such as variables, constants and functions during compilation. If the types do not match, the compiler will report an error. This type checking can help programmers find errors in their code early and reduce debugging time. In Golang, type definition is very simple. The concept of class can be implemented through structures, and interfaces can also be used for polymorphic programming.

In terms of type inference, the Golang compiler can infer the type of a variable or expression based on its context. This feature can omit many explicit type declarations, improving code readability and writing efficiency. For example:

var a int = 10
var b = 20
c := "hello"

In the above code, variables a and b are both integer types, while variable c is of string type. Among them, variable b does not have an explicitly specified type. The compiler infers that its type is int based on the context of its assignment expression, so there is no need to explicitly declare the type.

3. How to develop Golang without generics

In the absence of generics, Golang uses interfaces and type assertions to achieve similar effects to generics. Interfaces in Golang can implement dynamic typing functions like generics, and type assertions can recover specific type values ​​from interface types.

The use of interfaces allows programmers to write general code regardless of specific data types. For example:

type Animal interface {
    Talk()
}

type Dog struct {
    Name string
}

func (d Dog) Talk() {
    fmt.Println("woof woof")
}

type Cat struct {
    Name string
}

func (c Cat) Talk() {
    fmt.Println("meow meow")
}

func main() {
    zoo := []Animal{Dog{"Fido"}, Cat{"Kitty"}}

    for _, animal := range zoo {
        animal.Talk()
    }
}

In the above code, Animal is an interface type, which has a Talk() method. Dog and Cat are two specific animal classes, both of which implement the Talk() method of the Animal interface. In this way, in the main function, you can define an array containing any object that implements the Animal interface, and call the Talk() method on each object through a loop.

The use of type assertions can convert the value of an interface to its corresponding type at runtime. For example:

func printIntType(v interface{}) {
    if val, ok := v.(int); ok {
        fmt.Printf("%v is an int
", val)
    } else {
        fmt.Printf("%v is not an int
", val)
    }
}

func main() {
    printIntType(42)
    printIntType("hello")
}

In the above code, the printIntType() function accepts an empty interface as a parameter and uses a type assertion in the function body to convert the parameter to int type. If the conversion is successful, "val is an int" is printed, otherwise "val is not an int" is printed. This example shows how to use type assertions to obtain a value of a specific type from an interface.

4. Summary

The lack of generics in Golang is a well-known problem. It poses some challenges in type system, performance and language design. Although Golang's type system is very simple and easy to use, some troubles can arise when dealing with generic data types. For some programming tasks, using Golang without involving generics can get complicated. However, using Golang's interfaces and type assertions, we can still achieve a certain level of generic functionality. Although Golang does not have generics, there are many things worth mentioning in its handling of data types.

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