Function Key

dsl/user_type.go:261–272

Key makes it possible to specify validations for map keys. Example: Attribute("map", MapOf(String, Int), func() { Key(func() { Format(FormatDateTime) // map keys are timestamps }) })

(fn func())

//	    })
//	})
func Key(fn func()) {
	at, ok := eval.Current().(*expr.AttributeExpr)
	if !ok {
		eval.IncompatibleDSL()
		return
	}
	if m, ok := at.Type.(*expr.Map); ok {
		eval.Execute(fn, m.KeyType)
		return
	}
	eval.IncompatibleDSL()
}

// Elem makes it possible to specify validations for array and map values.
//