Go Programming Experience

Intermediate

Other Languages Experience

Javascript, Typescript, React/NextJS, PHP, C/C++

Related Idea

• Has this idea, or one like it, been proposed before?
• Does this affect error handling?
• Is this about generics?
• Is this change backward compatible? Breaking the Go 1 compatibility guarantee is a large cost and requires a large benefit

Has this idea, or one like it, been proposed before?

No

Does this affect error handling?

No

Is this about generics?

No

Proposal

Hello!
I would like to suggest a feature to the Go language.
It would be nice to be able to reference the field type of another model directly, similar to how TypeScript allows referencing types from other interfaces or classes.
I know I can define a type and use that type for it, but this would improve the process with less redundant code.

My situation:
Currently, when defining a model in GORM, I must explicitly specify the type of fields, including foreign keys, which can lead to inconsistencies and increased maintenance overhead when changing models etc.

In TS I can do this:

interface Product {
    id: number;
    name: string;
}

interface Order {
    productId: Product['id']; // References the type of Product's id
    quantity: number;
}

In the example, Order type references the type of Product's id property directly, ensuring that any changes to the Product interface will automatically reflect in the Order interface.

Thanks.

Language Spec Changes

Adding new way of defining struct type

Informal Change

No response

Is this change backward compatible?

Yes

Orthogonality: How does this change interact or overlap with existing features?

No response

Would this change make Go easier or harder to learn, and why?

This feature will definitely simplify learning Go to (not only) Typescript users.

Cost Description

No response

Changes to Go ToolChain

I guess type check features, syntax highlighters.

Performance Costs

No runtime, comptime is affected like similiar to adding new type to the code

Prototype

To implement a similar feature in Go, I suggest introducing a syntax that allows referencing another model's field type directly. As Go uses object a dot for struct data, either use a keyword typeof Model.Column or Model['Column'].

For example:

type Product struct {
    ID   uint   `gorm:"primaryKey"`
    Name string `json:"name"`
}

type Order struct {
    ProductID1 typeof Product.ID // Reference to Product's ID type
    ProductID2 Product['ID'] // alternative
    Quantity  int       `json:"quantity"`
}

Thanks for reading and feedback.