What c.l.py's opinions about Soft Exception?

[John Nagle]

Steven D'Aprano wrote:
> On Sat, 08 Mar 2008 22:24:36 -0800, Kay Schluehr wrote:
> 
>> On 9 Mrz., 06:30, Steven D'Aprano <st... at REMOVE-THIS-
>> cybersource.com.au> wrote:

>> Is it really so exotic that it requires the demand for more use cases?
> 
> 
> Are the existing solutions really so incomplete that we need yet another 
> solution?
> 
> What problem are you trying to solve with SoftExceptions?

    I actually implemented something like "soft exceptions" in a LISP
program long ago. I called them "gripes".  They were a way that a function
could complain about something it wanted the caller to fix. The caller
could either fix it or decline to do so.

    This was for a robotic planning application, where one module had detected
that some precondition that it needed wasn't satisfied.  This was usually
something like some physical object being in the wrong place for a later
operation, and a previously planned move needed to be modified. Passing
the problem back to the caller sometimes allowed an easy fix, rather than
aborting the whole plan and building a new one.

    This isn't a common problem.

    In the rare cases that it is needed, it can be implemented with callbacks.
It doesn't require a language extension.

    					John Nagle