Idea for handling errors in Go

In the last (and not only the last) time, many copies are broken about the inconvenience of error handling in Go.



The essence of the claims is that direct use:

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customVar, err := call() if err != nil { doSomething(err) return err } 

on large numbers of repetitions is much less convenient than the classic:

 try { String customVar = call(); } catch (BadException e) { doSomething(e); sendException(); } 

One can argue for a long time both on the subject of the claims and on the workarounds , however, there is indeed logic in the “package” approach.



In this connection, I had an idea about the handling of exceptions without much deviation from the “Go-way”. The option is not working - just my imagination.



It would look like this:

 try err { customVar1, err := call1() customVar2, err := call2() customVar3, err := call3() } catch { doSomething(err) return err } 

The general idea is this: right after try, a variable (in our case, err) of type error is declared, the scope of which is the entire try ... catch block. Further, each time a new value is assigned to a variable inside a try block, the compiler checks it for nil, and if an error is returned, the transition to the catch block follows. Theoretically, this is not a very expensive operation, performance should not suffer.



It is also possible to assign several variables, such as:

 try errIo, errNet { customVarIo1, errIo := callIo1() customVarIo2, errIo := callIo2() customVarNet1, errNet := callNet1() customVarNet2, errNet := callNet2() } catch { if errIo != nil { doSomething(errIo) return errIo } else { doSomething(errNet) return errNet } } 

In this case, the example is not very visual, but with a large amount of code inside the try, it can be useful to group the errors so that the catch does not reduce their processing to:

 switch err { case net.Error1: doSomethingWithNetError() case net.Error2: doSomethingWithNetError() case io.Error1: doSomethingWithIoError() case io.Error2: doSomethingWithIoError() } 

In general, I have everything. Scold.