> I've been having problems with this, and there has been talk about > decomissioning the j801 instance of the J debugger because of my problems.
Just to clarify: this refers to the GUI debugger, not the 13!:x primitives. There were known problems with the GUI debugger from some time back, and it was never intended to be migrated to J801 Qt. It has been removed from Qt now, pending a rewrite. On Tue, Mar 18, 2014 at 4:52 AM, Raul Miller <[email protected]> wrote: > 13!:19 is supposed to cut back the stack during debugging. > > I've been having problems with this, and there has been talk about > decomissioning the j801 instance of the J debugger because of my problems. > > Here's an illustration of these problems which (a) does not involve the > ide, and (b) does not involve any foreigns (other than the 13!: foreigns > used for debugging): > > First, definitions: > > aget=: {&(i.3 4)@| > anul=: 0 0 0 0"_ > > bget=: {&(-p:i.3 5) > bnul=: 0 0 0 0 0"_ > > bonly=: anul,bget > aonly=: aget,bnul > both=: aget,bget > > get=: [:`bonly`both`aonly@.(3&#.@:*) > > With these definitions in place, and a fresh j801 jqt instance, I see the > following behavior: > > First, let's generate an index error: > > get 4 > |index error: bget > | get 4 > > simple enough. Now, let's turn on debugging and try that again: > > 13!:0]1 > get 4 > |index error: bget > |bget[0] > ;:inv {."1]13!:13'' > bget bonly get > > Here, I see that 'get' called 'bonly' which in turn called 'bget', which is > where the index error happened. > > Now let's cut back the stack: > > 13!:19 '' > |index error: bget > |bget[0] > ;:inv {."1]13!:13'' > bget bonly get > > ... um... that was supposed to cut back the stack. Let's try that again: > > 13!:19 '' > ;:inv {."1]13!:13'' > bonly get > > perfect! This time it behaved exactly like it was supposed to behave. > > Now, let's try that again: > > 13!:19 '' > |index error: bget > |bget[0] > ;:inv {."1]13!:13'' > bget bonly get > > A picture is worth a thousand words, so: > > > http://31.media.tumblr.com/f3e5a3a867c285c003c66a12d9a26552/tumblr_mtpw2zQKNP1sj6vefo1_500.gif > > I totally understand that debuggers are a pain to write. Somehow you need > code which does the right thing with errors. But I'm not the only one that > has to deal with this headache, and maybe with this as a test case someone > can feel motivated enough to find the issue. (And, as a bonus, perhaps > write a simple test case to illustrate it? Or, failing that, maybe a really > simple fix?) > > Anyways, I've been able to reproduce this problem with this script, so > maybe others can also. (Fortunately, I've been getting good at finding > other ways of isolating problems...) > > Thanks, > > -- > Raul > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
