On Friday, 7 February 2014 at 14:26:48 UTC, Marc Schütz wrote:
Hmm... then what _does_ qualify as exceptional in your opinion?
A logic error (i.e. a mistake on the programmers side) doesn't,
IMO, it should abort instead. On the other hand, there is the
class of situations where e.g. a system call returns an error
(say, "permission denied" when opening a file, or out of disk
space). Or more generally, an external service, like a database
or a remote server. However, I can't see how these are
fundamentally different from invalid user input, and indeed,
there's often not even a clear separation, e.g. when a user
asked you to read a file they don't have access to.
So, what's left then?
It is exceptional situation if input is supposed to be valid but
surprisingly is not. For example, calling `decodeGrapheme` on
external string without making sure it is valid first. Same goes
for file - trying open a missing file is exceptional, but
checking for file presence is not.
