brent.pinkney at aircom.co.za
Tue Jan 27 14:04:16 UTC 2004
>> Does this not catch all the possibilities ?
> No, of course not. That's why I find the style of putting the resource
> creation inside the ensured block so terribly misleading. It puts you
> under the impression that you caught all the possibilities, where it is
> easy to
> see from an example like
> [file := (FileStream newFileNamed: 'foo.bar') halt.
> ] ensure:[file close].
> that you do not catch anything that happens on the right hand side of the
> assignment. IOW, execute the above and close the resulting debugger - it
> will end up with a DNU for file close which illustrates that - although
> file has been created - it is not being cleaned up after encountering the
Ahhh - I think a light has just gone on.
Am I correct in understanding that the assignment operator should instead
be thought of as a function call (as it can be in C++) which itself can
fail AFTER the rhs has been sucessfully evaluated but before the lhs has
been set to point to the result of said rhs computation ?
In the above example, the rhs whould have created a file but the lhs
(file) would never be set to reference it.
So the ensure: block would have no reference to the file which still needs
to be closed.
Keeps one sharp, this mailing list :)
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