Seems pretty slow to dispatch on a linear series of spec validations, but I don't see any reason it wouldn't work.
On Wednesday, September 13, 2017 at 3:47:40 PM UTC-5, Brent Millare wrote: > > The example for multi-spec provided in the spec guide assumes a key that > denotes a "type". (This key is used as the dispatch fn). In my situation, > I'm assuming I don't have control over what maps are generated. In other > words, I explicitly do not want to have to encode types into the input map. > Instead, I want to rely on the "shape" (key set), since that is the most > flexible. While I could create a dispatch function that analyzes the input > and produces a "type", that offers no advantages over what I presented > earlier. Adding more cases is not extensible since it requires redefining > the dispatch fn. In other words, I'd be just copying pasting my presented > function as the dispatch fn. > > Alex, did I address your point? Is the approach you are suggesting > different? > > Alternatively, my previous example might have been misleading since I used > keys to represent useful work. Perhaps it would have been better written as: > > (fn [m] > (condp clojure.spec.alpha/valid? m > ::foo-map-spec ... do foo stuff ... > ::bar-map-spec ... do bar stuff ...)) > > On Wednesday, September 13, 2017 at 3:46:43 PM UTC-4, Alex Miller wrote: > >> You might want to look at s/multi-spec which lets you create a variable >> open spec based on a multimethod, which would in this case be based on key >> availability. >> >> >> On Wednesday, September 13, 2017 at 11:54:31 AM UTC-5, Brent Millare >> wrote: >>> >>> I have several maps with different combinations of keys for each map. I >>> want to process each map but do different work depending on the set of keys >>> available, basically dispatch on key availability. I thought clojure.spec >>> might be a good fit for doing the classification step. So for each key, I >>> could define a spec. Next, I would use clojure.spec.alpha/keys to define a >>> spec for each set of keys I'd like to match. Finally, I would dispatch like >>> so: >>> >>> (fn [m] >>> (condp clojure.spec.alpha/valid? m >>> ::foo-map-spec :do-foo-stuff >>> ::bar-map-spec :do-bar-stuff)) >>> >>> Does this seem reasonable? >>> >>> The advantage in my mind is its thorough, explicit, and easy to read. >>> Possible downsides is performance if it mattered. >>> >>> What are the advantages/disadvantages to this approach compared to other >>> methods? >>> >> -- 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. For more options, visit https://groups.google.com/d/optout.
