On 5/8/20 5:37 PM, Henning Thielemann wrote:
I can imagine that it would be helpful for the user to get a stacked exception information like: Parse error on line 42, column 23 while reading file "foo/bar" while traversing directory "blabla"
That seems to be rather specific use case. It'd be a cool feature but I'm not aware of any programming language following that interpretation so far. I personally would be happy to be able to get the same type of stack trace for exceptions as in other programming langues (and as the proposal suggests).
If you must debug exceptions, then this sounds like exceptions were abused for programming errors.
I'd be pretty happy to be able to debug them better; no matter if they were "abused" for anything or not, I must still debug them in practice. Given that they traverse program flow invisibly (e.g. not lexically, like return values) and can become visible in different places than they arose, having a call stack to debug their creation would be useful.
a callstack is not useful for a user.
Call stacks have been very useful to me as a user of non-Haskell tools so far, because they are excellent for attaching to bug reports and usually led to developers fixing my problems faster.