I have a struct like so,
//
// HandlerInfo is used by features in order to register a gateway handler
type HandlerInfo struct {
Fn func(interface{})
FnName string
FnRm func()
}
where I want to pass a func:
func StarboardReactionHandler(e *gateway.MessageReactionAddEvent) {
// foo
}
i := HandlerInfo{Fn: StarboardReactionHandler}
Unfortunately, this results in:
Cannot use 'StarboardReactionHandler' (type func(e *gateway.MessageReactionAddEvent)) as the type func(interface{})
I found this workaround:
func StarboardReactionHandler(e *gateway.MessageReactionAddEvent) {
// foo
}
func handlerCast(e interface{}) {
StarboardReactionHandler(e.(*gateway.MessageReactionAddEvent))
}
i := HandlerInfo{Fn: handlerCast}
Is there some way that I can simplify needing handlerCast
, such as doing it inside my StarboardReactionHandler
or in HandlerInfo
? Maybe with generics or reflection? I basically just want to minimize the syntax / boilerplate that's required here.
CodePudding user response:
you can use interface{}.(type)
follow is a exmple:
package main
import "fmt"
type HandlerInfo struct {
Fn func(interface{})
FnName string
FnRm func()
}
type MessageReactionAddEvent = func(a, b int) int
func StarboardReactionHandler(e interface{}) {
switch e.(type) {
case MessageReactionAddEvent:
fmt.Printf("%v\n", (e.(MessageReactionAddEvent))(1, 2))
}
}
func add(a, b int) int {
return a b
}
func main() {
i := HandlerInfo{Fn: StarboardReactionHandler}
i.Fn(add)
}