How to implement golang service based on Apache Thrift with exceptions?

I have a service thrift interface for result method as follows:

exception SomeException {
    1: string message;
}

string result(
    1: string token,
    2: string identifier
) throws (
    1: SomeException ex,
);

How di I implement this properly in golang? I want exceptions to be thrown properly for clients of this Thrift service.

Here the Apache Thrift tutorial for Go comes into play. The tutorial consists of a small service:

enum Operation {
	ADD = 1,
	SUBTRACT = 2,
	MULTIPLY = 3,
	DIVIDE = 4
}

struct Work {
	1: i32 num1 = 0,
	2: i32 num2,
	3: Operation op,
	4: optional string comment,
}

service Calculator extends shared.SharedService {
	i32 calculate(1:i32 logid, 2:Work w) throws (1:InvalidOperation ouch),

	// some other methods ...
}

If the client passes a calculation operation to the server in this way:

work := tutorial.NewWork()
work.Op = tutorial.Operation_DIVIDE
work.Num1 = 1
work.Num2 = 0
quotient, err := client.Calculate(1, work)
if err != nil {
	switch v := err.(type) {
	case *tutorial.InvalidOperation:
		fmt.Println("Invalid operation:", v)
	default:
		fmt.Println("Error during operation:", err)
	}
	return err
} else {
	fmt.Println("Whoa we can divide by 0 with new value:", quotient)
}

the server should throw an exception as shown below. A similar thing happens when some unknown value for the w.Op is passed:

func (p *CalculatorHandler) Calculate(logid int32, w *tutorial.Work) (val int32, err error) {

switch w.Op {
	case tutorial.Operation_DIVIDE:
		if w.Num2 == 0 {
			ouch := tutorial.NewInvalidOperation()
			ouch.WhatOp = int32(w.Op)
			ouch.Why = "Cannot divide by 0"
			err = ouch
			return
		}
		val = w.Num1 / w.Num2
		break
		
	// other cases omitted
	
	default:
		ouch := tutorial.NewInvalidOperation()
		ouch.WhatOp = int32(w.Op)
		ouch.Why = "Unknown operation"
		err = ouch
		return
	}
	
	// more stuff omitted
}

The short answer is that Thrift Interfaces implement the error interface (Error() string function) . Thus can be returned just like any go error, usually like return nil, err.