Sorry, I got this wrong (which shows how much this comes up). You can indeed use nested names in current kdb+, as in:
q).a.b.c:123 q).a.b.c 123 What you cannot do is change context to more than one level below root, e.g. this is OK: q)\d .a q.a) this fails: q)\d .a.b '.a.b So nested names is not fully supported. Back to J, I have never felt the need for nested names, though I obviously use them in Java and similar languages. Perhaps this is because J gets by with much shallower locale paths compared to more traditional languages. On Sun, Mar 2, 2014 at 12:35 PM, chris burke <cbu...@jsoftware.com> wrote: > > Contrast this with the K tree which I think allows names like this: > > > > .node1.node2.node3.leaf > > No, this is not possible, at least in the current kdb+ system. > > > > On Sun, Mar 2, 2014 at 12:28 PM, Raul Miller <rauldmil...@gmail.com>wrote: > >> What I mean by that is that locales cannot contain other locales. >> >> name_locale_ >> >> Contrast this with the K tree which I think allows names like this: >> >> .node1.node2.node3.leaf >> >> (using the . to separate names rather than _ and working from left to >> right >> rather than from right to left). >> >> Of course, K sacrifices "OOP" in its focus on speed. So it might not be so >> good in an educational context. But I highly respect Arthur Whitney's >> taste >> in tradeoffs, and I think they are worth keeping in mind, especially when >> offering explanations. >> >> In J, you can have names like this_is_an_example (with embedded >> underlines) >> and you can reference that in a locale by including a locale suffix: >> >> this_is_an_example_base_=: 1 >> >> or >> foo=: <'base' >> this_is_an_example__foo=: 2 >> >> But this is an error: >> foo=: <'this_is_odd' >> this_is_an_example__foo=: 3 >> |ill-formed name: foo >> >> Only the last two underlines matter currently, in J, and locale names >> cannot contain the '_' character. The other optional '_' characters in >> names are just decoration. >> >> Does this make sense? >> >> Thanks, >> >> -- >> Raul >> >> >> On Sat, Mar 1, 2014 at 10:58 PM, chris burke <cbu...@jsoftware.com> >> wrote: >> >> > > ... they all exist on the same level >> > >> > I am not sure what you mean by this, but J has had locale paths since >> J4, >> > for example this enables OOP, e.g. create an object from a class. See >> > http://www.jsoftware.com/papers/joop.htm >> > >> > >> > On Sat, Mar 1, 2014 at 2:22 PM, Raul Miller <rauldmil...@gmail.com> >> wrote: >> > >> > > Directories are hierarchical - you can have a directory "inside" >> another >> > > directory. >> > > >> > > There's no way of doing that with locales - they all exist on the same >> > > level (though of course you can have a reference to any locale inside >> any >> > > locale). >> > > >> > > Thanks, >> > > >> > > -- >> > > Raul >> > > >> > > >> > > >> > > On Sat, Mar 1, 2014 at 12:25 AM, Don Guinn <dongu...@gmail.com> >> wrote: >> > > >> > > > I don't understand what you mean when you say "locals are not >> > > > hierarchical". Locales are just name spaces. Locales are implicitly >> > > > referenced through path (18!:2). The path determines how locales are >> > > > searched to resolve a name not found in the current locale. This >> search >> > > is >> > > > hierarchical. The locales are searched in the order specified in >> 18!:2. >> > > But >> > > > each locale has its own path. In this way the hierarchy of locales >> > > depends >> > > > on the current locale. In this way it is easy to implement classes >> in >> > J. >> > > > But paths can be used outside of J classes in interesting ways. >> > > > >> > > > >> > > > On Fri, Feb 28, 2014 at 8:52 PM, Steven Taylor <tayl...@gmail.com> >> > > wrote: >> > > > >> > > > > the verbname__location / verbname_location_ format places more >> > emphasis >> > > > on >> > > > > the verb or noun inside that locale (assuming a left to right >> > cultural >> > > > > reading orientation). That appears illogical because nobody else >> > does >> > > > > that, however it can help with readability if you can get used to >> it. >> > > > > >> > > > > It also helps if you can flatten out the locale 'tree' (although >> > > locales >> > > > > are not hierarchical). I mean just symantically. >> > > > > >> > > > > I found the process of re-evaluating how I initially thought >> > namespaces >> > > > > 'should' work refreshing and overall I think locales have helped >> me >> > > make >> > > > > better namespace naming choices in other more verbose languages. >> > > > > >> > > > > I'd also encourage considering locales outside of a strict oo >> > context. >> > > > > Try to stay away from state when possible. >> > > > > >> > > > > This is so obvious I am embarrassed that it took me so long to >> > consider >> > > > > this -- there are French and english 'locales' in Canada... And I >> > > thought >> > > > > this sense of the word may have been behind J's use of it. >> Probably >> > > > that's >> > > > > obvious to everyone in north America ;-). >> > > > > >> > > > > If you find yourself writing >> > > > > A wrapper just around a structure like this >> > > > > Dictionary<string,Dictionary<string,obj>>, you'll know that >> locales >> > > have >> > > > > grown on you. I may have done that recently >> > > > > ;) >> > > > > >> > > > > -Steven T. >> > > > > >> > > > > >> > ---------------------------------------------------------------------- >> > > > > 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 >> > >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm >> > > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
