Perhaps using try. and catch. misled the discussion as it was dealing with an error in the definition. Instead consider
f=:3 : 0 if. 0=3!:0 y do. +:y else. 'y is not an integer'(13!:8)123 end. ) I know, a silly example. Here f is intended to only take integer arguments. There is no error in the definition. The error is in the statement invoking f by trying to use it in a way not intended. Just like + reports a domain error for a non-numeric argument, not in the definition of +, but in the statement envoking + . I see (13!:8) as a way for users to report an error in the way an explicit definition is being used. On Tue, May 31, 2016 at 9:15 AM, Henry Rich <henryhr...@gmail.com> wrote: > [Better late than never] > > 13!:8 itself creates an error. Here, everything was going along great: > +y failed, but the error was caught, and it was all going to be OK until we > crashed on 13!:8. So as far as the JE is concerned, the 13!:8 line IS > where the error is. A try. in an earlier verb might trap it. > > A reasonable change would be this: if error-text is given for 13!:8, > that text becomes the entire error-massage, and 13!:8 will not add the > 13!:8 line too. > > That would leave you responsible for seeing what line failed, which you > can do with 13!:12'' before executing 13!:8. 13!:8 isn't going to be able > to point to the failing line. > > Comments, please. > > Henry Rich > > On 5/18/2016 12:10 PM, Don Guinn wrote: > >> It has always bugged me that debug signal message is not correct. Now that >> the J source is open for suggestions for changes I would like to suggest a >> change to the message. >> >> Given: >> >> f >> >> +-+-+------------------------------------+ >> >> |3|:|try. +y | >> >> | | |catch. 'y is not numeric.'(13!:8)123| >> >> | | |end. | >> >> +-+-+------------------------------------+ >> >> 'First', f 'Last' >> >> |y is not numeric. >> >> | 'y is not numeric.' (13!:8)123 >> >> 'First', + 'Last' >> >> |domain error >> >> | 'First', +'Last' >> >> >> Notice that the second error message shows the caller's line in error, not >> the line issuing the message. It would be more meaningful if the display >> were: >> >> 'First', + 'Last' >> >> |y is not numeric. >> | 'First', f'Last' >> >> Granted, if debug were on then the suspension and message should be as it >> is now, but when it is off using the line from the caller makes more >> sense. >> ---------------------------------------------------------------------- >> 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
