Is there a way to avoid duplication between docs and validation?

[D00mch]

I noticed that we have to duplicate the SKU pattern both in the documentation:

type Product struct {
        ...
	// the SKU for the product
	//
	// required: true
	// pattern: [a-z]+-[a-z]+-[a-z]+
	SKU string `json:"sku" validate:"sku"`
}

and the validation function:

func validateSKU(fl validator.FieldLevel) bool {
	// SKU must be in the format abc-abc-abc
	re := regexp.MustCompile(`[a-z]+-[a-z]+-[a-z]+`)

In Clojure, I would create a spec (schema) that could be reused both in documentation and the validation. How can we achieve something similar in Go to avoid duplicating these patterns?