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?
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