use ILookup instead of Associative
On Fri, Jan 18, 2013 at 11:00 AM, Ben Wolfson <wolf...@gmail.com> wrote: > I've got a bit of code implementing Associative, in order to provide a > fake map that responds to all calls to valAt with the same object, no > matter what the key is. > > Since it therefore "contains" every possible key, it doesn't make much > sense to call keys or seq on it (and it doesn't make *much* sense to > call vals on it if you expect the result of vals to be equinumerous > with the key/value pairs in the map). Nor does it make much sense to > call count on it. > > However, since Associative extends IPersistentCollection extends > Seqable, the result is an instance of Seqable, and coll? returns true, > etc., even though, as I said, the promises those interfaces make don't > really make sense. > > I could just extend ILookup, which contains only valAt, but I'd also > like to be able to implement containsKey and entryAt, which AFAICT are > only found in Associative. (If I'm wrong, please let me know---I know > that count is found in e.g. both IPersistentCollection and Counted.) > And in any case I'd like to be able to use IPersistentMap as well, for > without. There are sensible definitions of all the functions > specifically defined for IPersistentMap and Associative, but there are > *not* sensible definitions for all of what they bring along. > > Is there a way to weasel out of this? Force coll? to return false, > make the runtime think these pseudo-maps aren't instances of Seqable? > Being enumerable or seqable is not a necessary property of something > that maps keys to values. > > -- > Ben Wolfson > "Human kind has used its intelligence to vary the flavour of drinks, > which may be sweet, aromatic, fermented or spirit-based. ... Family > and social life also offer numerous other occasions to consume drinks > for pleasure." [Larousse, "Drink" entry] > > -- > 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 > -- And what is good, Phaedrus, And what is not good— Need we ask anyone to tell us these things? -- 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
