On: Lies we tell ourselves to keep using Golang (2022)

[the_gipsy]

How? Stringly matching? That's not typesafe at all.

[wbl → the_gipsy]

No it wraps the underlying error

[the_gipsy → wbl]

But the underlying error stays unmatchable. Doesn't sound like a solution if you have to duplicate every error type, and worse, they don't even map 1:1 but now you have the same underlying error wrapped to god knows how many different errors.

For example, the lib produces some an error "bad file descriptor". You'll be wrapping it when you call fileOpen, fileDelete, etc etc 20 times. So you will be wrapping it in "open error", "delete error", etc, 20 times. You cannot try to match it to "bad file descriptor", that information is lost, you now have 20 relatively useless errors.

Except if you stringly match.

[wbl → the_gipsy]

https://pkg.go.dev/errors#Is and https://pkg.go.dev/fmt#Errorf clearly state that there is a way to match these errors if the package exposes the values, which the stdlib does.

[Yoric → wbl]

Which only works when the error itself doesn't contain any information.

It's better than nothing, of course.

[the_gipsy → wbl]

Ah okay, it seems to work because errors are pointers, and errors.Is just checks for equality.