Thanks, Raul. These are impossible errors to trigger just by using J code. On reflection i guess that's going to be the story with most if not all of them.
On Tue, May 20, 2014 at 11:58 PM, Raul Miller <[email protected]> wrote: > File access error can happen when permission is denied by the host > operating system. > > For example: > > $ date >/tmp/example; chmod 0 /tmp/example; ijconsole > 1!:1<'/tmp/example' > |file access error > | 1!:1<'/tmp/example' > > I think allocation error is similar - I expect that it would happen when J > asks for memory and none is available (it's analogous to ws full - but it's > not happening inside J's accounting system). > > Thanks, > > -- > Raul > > > On Tue, May 20, 2014 at 6:08 PM, Roger Hui <[email protected] > >wrote: > > > s=: 1 $. 100;0;2 > > t=: 1 $. 200;0;3 > > s,"0/t > > |non-unique sparse elements > > | s ,"0/t > > > > For that matter, I'd expected that s,t would signal the same error, but > it > > doesn't. I guess if I looked at the source I can figure out why that is. > > > > s,t > > |nonce error > > | s ,t > > > > In contrast: > > > > s ,"0/ s > > $ s ,"0/ s > > 100 100 2 > > 3 $. s ,"0/ s NB. the sparse element > > 2 > > > > I expect "read only data" to be signaled if you try to amend data which > is > > mapped on a read-only file (e.g. if the mapped file is on a CDROM). > > > > "stop" would be signaled when execution reaches a line in an explicit > defn > > which has stop set. > > > > "break" would be signaled if (on Windows) you hit the yellow J icon while > > the J session is executing. e.g. execute 6!:3]100 and then hit the > yellow > > icon 2 or 3 times. > > > > "input interrupt" would be signaled if you asked for "terminal input", > > 1!:1]1, hit the yellow icon, and then enter. It dates from a time when > it > > was possible to enter o backspace u backspace t (remember that?) in > > response to 1!:1]1. > > > > "system error" is not supposed to happen. > > > > Not sure about "file access error". > > > > > > > > > > > > On Tue, May 20, 2014 at 2:32 PM, Ian Clark <[email protected]> > wrote: > > > > > For NuVoc purposes I'm documenting J's error messages... > > > > > > Have you ever seen any of the following error messages in your J > session > > > (j602 onwards)? > > > > > > allocation error > > > break > > > file access error > > > input interrupt > > > non-unique sparse elements > > > read-only data > > > stop > > > system error > > > > > > If so, can you furnish a simple sample of "normal" J code that causes > the > > > said error? > > > > > > I specify "normal" because I don't want samples which rely on > > constructing > > > a pathological noun as a core image in hex and shoe-horning it into J > by > > > use of 3!:2, or use of the "darker" Foreigns, especially undocumented > > ones. > > > I want something which could conceivable arise by bona-fide J usage by > an > > > innocent newbie, ill-conceived though it might seem to someone more > > > experienced. > > > > > > Having said that, it probably takes deep knowledge of the J source to > > know > > > what might trigger some of these errors. > > > > > > It would also be nice to know which of the above error messages can't > > > possibly arise in normal usage. (But consider it "cheating" to use > 13!:8 > > to > > > signal any given message: assume I know how to do that.) > > > ---------------------------------------------------------------------- > > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
