I think you missed the point of the last two emails. In tools.analyzer Nicola and I use the keywords :ctx/statement, :ctx/expr, :ctx.invoke/target and some others. The namespace "ctx" is entirely synthetic. It has no representation in terms of a file or actual Clojure ns form. It's just a conceptual namespace used in naming a set of keyword values.
My reading of James and Jozef's last emails is that you can use exactly this model, where you simply invent a prefix for your keywords, the conventional name for which is a "namespace", and use that rather than trying to use the :: syntax to generate namespace qualified keywords. Having a dedicated namespace for your hierarchy just to use :: is probably the wrong approach since you're presumably going to have to write those namespaced keywords elsewhere in your codebase. Reid On 08/09/2014 03:21 PM, larry google groups wrote: > > > Keywords hierarchies need to be namespace qualified, but you can > require > > namespaces and use the alias, as I demonstrated in my earlier example. > > I wasn't thinking clearly about what this meant, but now I see what > you mean. I could potentially have all of my (derive) statements in > one namespace, define the keywords there, and then any namespace that > will use those keywords can require that namespace and use those > keywords. Thank you for your help. > > > > > On Saturday, August 9, 2014 4:02:59 PM UTC-4, James Reeves wrote: > > Keywords hierarchies need to be namespace qualified, but you can > require namespaces and use the alias, as I demonstrated in my > earlier example. > > To give a further example, suppose you have a namespace like: > > (ns example.other) > > (derive ::dog ::animal) > (derive ::cat ::animal) > > (defmulti speak identity) > > If you require this namespace, you can use the alias instead of > the fully qualified name in keywords: > > (ns example.core > (require [example.other :as o])) > > (defmethod o/speak ::o/dog [_] "bark") > (defmethod o/speak ::o/cat [_] "meow") > > - James > > > On 9 August 2014 20:49, larry google groups <lawrenc...@gmail.com > <javascript:>> wrote: > > Thank you for the responses. However, when I look here: > > http://clojure.org/multimethods <http://clojure.org/multimethods> > > I see that it says: > > "You can define hierarchical relationships with (derive child > parent). Child and parent can be either symbols or keywords, > and must be namespace-qualified" > > Is there any way I can establish a hierarchical relationship > without it being name-spaced qualified? I would like to be > able to (slingshot/throw+ {:type some-symbol}) and have this > be caught in a different namespace, but I need a way to match > the some-symbol, and I would ideally like it if some-symbol > might be part of a hierarchy, such that I'm matching again > some-symbol's parent. > > Is that possible? > > I guess I could hard-code all of the namespaces, such that the > symbols are all: > > some-namespace/some-symbol > > but that does great reduce the flexibility of the system. > > > > > > > On Saturday, August 9, 2014 3:30:33 PM UTC-4, James Reeves wrote: > > Jozef is correct, but to give some examples: > > (ns example.core > (:require [example.other :as other])) > > (= ::foo :example.core/foo) > (= ::other/foo :example.other/foo) > > (not= :foo :example.core/foo) > (not= :example.core/foo :example.other/foo) > (not= :other/foo ::other/foo) > > - James > > > > On 9 August 2014 19:14, Jozef Wagner <jozef....@gmail.com> > wrote: > > Keep in mind that :: is just a syntax sugar that is > processed by the reader, before the compiler kicks in. > ::foo is a shorthand for :your.current.ns/foo. Its > purpose is to make it easy to create keywords that do > not clash with other ones. > > Keywords are equal (and identical) only when both of > their namespaces and names are equal. :ns1/foo is thus > not equal to :ns2/foo, nor to just :foo. :: is used in > cases where you want to exploit this important > property of keywords, so that your keyword won't e.g. > clash with other keywords in a collection, contents of > which you don't know. > > Jozef > > > On Saturday, August 9, 2014 7:46:45 PM UTC+2, larry > google groups wrote: > > Please forgive this stupid question, but I'm still > trying to understand exactly what the double "::" > means. I have read that I can use (derive) to > establish a hierarchy and I can imagine how this > would be useful for things like throwing errors > and catching them and logging, but I've also read > that "::" adds the namespace to the symbol, so I > would assume that I can not match ::logging from > one namespace with ::logging from another? > > I'm thinking of this especially in my use of > Slingshot, where I was thinking of doing something > like: > > (throw+ {:type ::database-problem :message > "something wrong in the database query"}) > > and then at a higher level in my code I was going > to catch it with something like: > > (derive ::database-problem ::logging) > > and then using Dire: > > (dire/with-handler! #'database/remove-this-item > [:type ::logging] > (fn [e & args] > (timbre/log (str " database/remove-this-item: > The time : " (dates/current-time-as-string) ( str > e)))) > > but conceptually I am having trouble understanding > how ::logging in one namespace can match ::logging > in another namespace. Perhaps I should just use > normal keywords? > > > -- > You received this message because you are subscribed > to the Google > Groups "Clojure" group. > To post to this group, send email to > clo...@googlegroups.com > > Note that posts from new members are moderated - > please be patient with your first post. > To unsubscribe from this group, send email to > clojure+u...@googlegroups.com > > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en > <http://groups.google.com/group/clojure?hl=en> > --- > You received this message because you are subscribed > to the Google Groups "Clojure" group. > To unsubscribe from this group and stop receiving > emails from it, send an email to > clojure+u...@googlegroups.com. > > For more options, visit > https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. > > > > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to clojure@googlegroups.com > Note that posts from new members are moderated - please be patient > with your first post. > To unsubscribe from this group, send email to > clojure+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en > --- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send > an email to clojure+unsubscr...@googlegroups.com > <mailto:clojure+unsubscr...@googlegroups.com>. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Clojure" group. 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