Thanks for this suggestion, Ben. I ultimately went with a combination of this suggestion (dynamically determining associativity) and Ronald's suggestion (allowing the user to choose). My parser will start with the associativity used by NSExpression, but provides a property to change it.
Thanks! Dave On Nov 21, 2010, at 3:33 AM, Ben Haller wrote: > Another option would be to make your code mimic whatever NSExpression is > doing on that machine, by evaluating 2 ** 3 ** 2 (once, and caching the > result) and seeing whether it comes out as 64 or 512. That way if/when Apple > fixes their bug, your code will seamlessly follow suit. > > Which of these alternatives is best depends upon how your code is going to > be used, of course. Roland's suggestion of a compatibility switch seems > good; the behavior I suggest could be a third option for that switch. Then > the user of the class can decide what they want to get. Probably the best > default would be to use the correct (right associative) parsing, though, as > it seems unlikely that a whole lot of code specifically depends upon this bug > in NSExpression, so for most clients there is probably no need to propagate > the buggy behavior... > > Ben Haller > McGill University _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
