The Right Approach to Exceptions

[Andrei Alexandrescu]

On 2/19/12 8:52 PM, H. S. Teoh wrote:
> On Sun, Feb 19, 2012 at 08:33:04PM -0600, Andrei Alexandrescu wrote:
>> On 2/19/12 7:53 PM, H. S. Teoh wrote:
>>> I stand by my objection that if something might succeed if it can be
>>> retried, then it needs to be retried in the called function, not the
>>> caller.
>>
>> If read fails from a socket, it's of no use to try it again. One must
>> close the socket, reconnect, and attempt the whole operation once
>> again.
> [...]
>
> Correct, so that would be a recovery strategy at the operation level,
> say at sendHttpRequest or something like that. There is not enough
> information available to sendHttpRequest to know whether or not the
> caller wants the request to be retried if it fails.
>
> But if the higher-level code could indicate this by way of a recovery
> policy delegate, then this retry can be done at the sendHttpRequest
> level, instead of percolating up the call stack all the way to
> submitHttpForm, which then has to reparse user data, convert into JSON,
> say, and then retry the entire operation all over again.
>
> I'm really liking the Lisp approach.

Now we're talking. Ideas. Outside the box.

Andrei