Hi Kashyap Try: (rel tgs (+List +Ref +Joint) NIL itm (+Tag))
+Idx is for +String, actually a special variant of the general non-unique index +Ref. Be aware that the relation classes may have parameters - in same order as the prefix classes: (rel <rel-name> (<Prefix-Class-1> <Prefix-Class-2> ... <Type-Class>) <Prefix-Class-1-Argument> <Prefix-Class-2-Argument> ... <Type-Class-Argument>) Now I'm currently unsure if +Ref and +Joint can be combined... might be that +Joint cannot be indexed? Alex? Regards, beneroth On 23.11.19 16:49, C K Kashyap wrote: > Thanks Alex, > How can I add +Idx to tgs? That should be possible right? > When I add +Idx to tgs, I get "tgs -- No Link" error. > Regards, > Kashyap > > On Fri, Nov 22, 2019 at 11:07 PM Alexander Burger <a...@software-lab.de > <mailto:a...@software-lab.de>> wrote: > > Hi Kashyap, > > > (collect 'tgs '+Item (db 'nm '+Tag "BLUE")) does not seem to > work for me - > > Sorry, my fault! I did not test. > > > returns NIL. For that matter, even (collect 'tgs '+Item) returns > NIL. I > > wonder if its because 'tgs does not have +Idx in the relation > > > > (class +Item +Entity) > > (rel ttl (+IdxFold +String)) > > (rel tgs (+List +Joint) itm (+Tag)) > > (rel sts (+IdxFold +String)) > > Right, we cannot 'collect' using the 'tgs' relation, as it has no > index. > > > > Also, (mapcar '((This) (: itm)) (collect 'nm '+Tag "BLUE")) > worked fine - > > now I see the beauty of "This" better. Btw, I had to get rid of > "T" in (collect > > 'nm '+Tag "BLUE" NIL T 'itm) to get it to work. > > Ah, haha, sorry again :) > > You can either > > (collect 'nm '+Tag NIL T 'itm) > > i.e. collect *all* tags (from minus infinte to plus infinite), or > > (collect 'nm '+Tag "BLUE" "BLUE" 'itm) > > to collect only the blue ones (from and till are "BLUE"). > > ☺/ A!ex > > -- > UNSUBSCRIBE: mailto:picolisp@software-lab.de > <mailto:picolisp@software-lab.de>?subject=Unsubscribe >
