On 6.02, no-match does return shape 0 5: $ 1!:0 '\bin\kdfslgjskd' 0 5
For concatenating such lists I use endtoend =: 1 : ';@:(<@u)' 1!:0"0 endtoend 'C:\J\bin\*.dll';'C:\J\bin\*.ijs';'C:\J\bin\*.nonexist' +---------------------+------------------+-------+---+------+ |j.dll |2008 3 4 10 0 36 |1642496|rw-|-----a| +---------------------+------------------+-------+---+------+ |jnative.dll |2008 2 23 11 30 42|53248 |rw-|-----a| +---------------------+------------------+-------+---+------+ |profile.ijs |2008 2 9 18 34 40 |1219 |rw-|-----a| +---------------------+------------------+-------+---+------+ |profilex.ijs |2008 2 2 17 33 25 |783 |rw-|-----a| +---------------------+------------------+-------+---+------+ |profilex_template.ijs|2008 2 9 18 41 0 |882 |rw-|-----a| +---------------------+------------------+-------+---+------+ Henry Rich > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > [EMAIL PROTECTED] > Sent: Saturday, June 28, 2008 11:55 PM > To: [email protected] > Subject: Re: [Jprogramming] Extra empty item from an empty table > > Don Guinn wrote: > > (2 2$;:'abc de fg h'),;2#<,:;:'ww xxxx' > > (2 2$;:'abc de fg h'),;1#<,:;:'ww xxxx' > > (2 2$;:'abc de fg h'),;0#<,:;:'ww xxxx' > >Why is there a third item which is empty in the last case? Am I > >misunderstanding something about append? > > Take a look at the shapes of your three right sides, i.e. > ;2#<,:;:'ww xxxx' > ;1#<,:;:'ww xxxx' > ;0#<,:;:'ww xxxx' > > and compare this with the (much simpler) right sides > 2 # ,: ;: 'ww xxxx' > 1 # ,: ;: 'ww xxxx' > 0 # ,: ;: 'ww xxxx' > > which all append nicely. > > Returning to your original problem: I consider the design of > 1!:0 to be botched. I'd prefer it to return an empty 0 6 matrix > in the case of non-matches. Also, it should work on the > root directory as it does on any other directory. I always > have to code around these special cases. (The standard > 'dir' wrapper doesn't extend nicely to empty matches, either.) > > Martin > ---------------------------------------------------------------------- > For information about J forums see > http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
