The crash in _.".'circ' has now been fixed for the next release. Thank you for finding and reporting this error.
----- Original Message ----- From: Ian Clark <[email protected]> Date: Thursday, March 18, 2010 3:57 Subject: Re: [Jprogramming] A J phrase which crashes Java on the iMac To: Programming forum <[email protected]> > Yes, Roger, that was my attitude with Adaytum Planning, when Ellis > Morgan and I recorded: "only a fool would do that!" in a voice > dripping with scorn -- and it actually got shipped in a release! I'll > lend you the WAV if you like :-) > > And yes - I did read the warnings. But I guess I unconsciously > distinguish between features whose results are unreliable and those > which compromise integrity by permitting a hard crash with legal > usage. With all due respect I have to ask: is Indeterminate (_.) a > supported feature, or an unsupported forensic side-effect that just > happens to be documented in Voc? A prominent warning there that > it can > crash J would be nice. So would a domain error when (_.) is used as > the left arg to Numbers (".) > > (_.) would be a useful facility (at least I think so) were it > safe to > use, as I imagine Infinity (_) is. I'm porting a calculator from APL > in which every number can take the pseudo-values UNDEFINED or INVALID > -- and there is some pervasive and very cumbersome code to support > this. So far I've been able to dispense with it all -- it was a major > reason for porting to J. But if I can't trust (_.".) when > applied to > raw user input then I'm going to have to bring some of it back. > > I do appreciate that when it comes to supporting "_." it might have > been a bridge too far. All I really want is to report a loophole > enabling an over-creative user to crash J. I'd also like to know > whether it happens on other platforms. Apple (Snow Leopard) > seems to > accept that it's Java that crashes -- and it's Sun's problem to fix > it. > > Ian > > > On Thu, Mar 18, 2010 at 12:02 AM, Roger Hui <[email protected]> > wrote:> It comes from deliberately using _. despite warnings > against it. > > > > > > > > ----- Original Message ----- > > From: Ian Clark <[email protected]> > > Date: Wednesday, March 17, 2010 16:44 > > Subject: [Jprogramming] A J phrase which crashes Java on the iMac > > To: Programming forum <[email protected]> > > > >> _.". 'circ' > >> > >> ...causes a hard crash of J on the iMac which loses all J-related > >> evidence but results in a bug report being mailed off to Apple. > >> The report is headed: J quit unexpectedly while using the > >> libj.dylib plugin. > >> > >> There's no facility for stopping the report being sent, so I've > >> spammed Apple trying to investigate a capricious bug in my > >> application, which turns out to be all down to this. > >> > >> The string 'circ' can be replaced by: 'circl', 'chur', and (many?) > >> words beginning 'chur'. Strangely, 'circle' works ok as expected. > >> > >> Is anyone curious as to how someone might stumble upon a bug > >> like this? ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
