Best Practices for Utilizing a Common Function Across Structs with Identical Fields

In scenarios where two structs possess identical fields, it is desirable to prevent code duplication when defining methods that operate on those fields.

Custom Type as Method Receiver

The recommended approach is to introduce a custom type (e.g., Version) that serves as the method receiver. Since all custom types can be utilized as method receivers, this technique enables the creation of a single method that can be applied to multiple structs.

Composition

Once the custom type is defined, it can be incorporated into the structs using composition. This involves embedding the custom type within the structs, essentially creating a nested structure.

Example

Consider the following code snippet:

type Version string

func (v Version) PrintVersion() {
    fmt.Println("Version is", v)
}

type Game struct {
    Name               string
    MultiplayerSupport bool
    Genre              string
    Version
}

type ERP struct {
    Name               string
    MRPSupport         bool
    SupportedDatabases []string
    Version
}

Here, the Version type serves as the method receiver, and its PrintVersion method can be accessed by both the Game and ERP structs due to their embedded Version fields.

Usage

The embedded Version field can be used and modified just like any other field:

main() {
    g := Game{
        "Fear Effect",
        false,
        "Action-Adventure",
        "1.0.0",
    }

    g.PrintVersion() // Version is 1.0.0

    e := ERP{
        "Logo",
        true,
        []string{"ms-sql"},
        "2.0.0",
    }

    e.PrintVersion() // Version is 2.0.0
}

By employing this approach, code repetition associated with duplicate methods is eliminated while maintaining flexibility and type safety.