Welcome to one of the best things about Clojure - the community. However, if anyone starts using the phrase 'Clojurian' then it is time to leave :-).
On Wed, 28 Sep 2016, at 07:17 PM, p...@pwjw.com wrote: > Wow thank you all for the really useful responses. How great. I > appreciate the time. > > as-> cleans up a couple of ugly bits of my code already, yes. And I'm > sort of irritated with myself for not thinking of _ (if (throw)) in my > let but yes that's a perfect idiom. > > > I totally get the minimalist approach in clojure.test and like it. In > fact, the ease of testing (and how easy it is to get coverage running > with cloverage) is one of the things I find the most impressive. > expectations looks interesting though too for a lot of my tests and > I'll spend some time with it too. > > The idiom of "most important is first unless its a sequence then it is > last" is really natural too; but I think it's what makes me end up > switching from ->> to ->. Putting a "first" in the middle of a ->> > expression is, I suppose, a hint that I'm switching. Looking at my > code, it really seems to be a mix of ->> and "doto" that I'm looking > for. Here's a fragment, for instance, that returns me an opened > instance of the first core midi device with a name that can receive > messages. (and I know I should error check that there is one after > that filter... that's on my todo list). An "as-> doto" pair would help > and I'll get right on that later on this week. > > (->> (MidiSystem/getMidiDeviceInfo) > (filter #(= (.getName ^MidiDevice$Info %) name)) > (map #(MidiSystem/getMidiDevice ^MidDevice$Info %)) > (filter #(>= (.getMaxTransmitters ^MidiDevice %) 0)) > first > (#(do (.open ^MidiDevice %) %)) > (#(.getReceiver ^MidiDevice %)) > ) > > Anyway, wow thanks again for all the responses! > > > > > > On Wednesday, September 28, 2016 at 10:31:37 AM UTC-4, > pa...@pwjw.com wrote: >> Hi. >> >> I'm new to clojure, and it is quite lovely. The threading model is >> great, the emacs integration is super, and the tasteful lisp >> extensions are good. A very nice programming environment all around. >> >> But as I write more code I find a couple of structures I'm using a >> lot which seem related to me not knowing idioms for a couple of uses >> cases. So thought I'd ask and see if you have any suggestions. >> >> Apologies if this is covered elsewhere. And if I should read some >> existing documentation I didn't find, I apologize for missing it. And >> thanks in advance for your time reading! >> >> First the thrush operators (-> and ->>) are super handy. But I find >> myself needing to 'move' arguments every now and then. So I get code >> which looks like >> >> (->> blah >> (do-this) >> (do-that arg) >> ((fn [s] (rearrange arg s arg)))) >> >> quite a lot.The alternate is a big nested let like >> >> (let [ first (blah) >> second (do-this first) >> ... >> result (wrap-it-up fourteenth) ] >> result) >> >> for sort of sequential application where arguments fall in different >> 'spots'. So I sort of find myself wanting to write a 'positional- >> thrush' macro like >> >> (-%> blah >> (do-this %) >> (do-that arg %) >> (do-the-other a1 % a2)) >> >> where % is replaced with the output of the prior. But no such >> operator exists as far as I can see. So either I've had a good idea >> (which is unlikely since I'm super new to the language) or there's >> some other idiom you all use for this pattern which I've missed. >> >> The second is smaller, but is more a question. clojure.test seems to >> only have 'is' so for things like equality I end up writing (is (= >> (...) (...))) a lot. Or to test if an exception is thrown (is >> (thrown? ...)). That's OK, but I'm wondering what led to that >> decision rather than having is-eq and is-thrown and so on >> (considering the core language has shortcuts like when and unless and >> if-not so the compound macros seem idiomatic). >> >> The last is sort of related to the first. Sometimes I'm assembling a >> data structure in a set of operators and I write them with a let or a >> -> and half way through I have an error condition I want to check. In >> a mutable procedural language you would do something like >> >> x = blah >> y = bim >> if (! (condition (y))) throw "y doesn't meet condition" >> z = blob >> >> I don't see a good idiom for this. I have to split and nest lets for >> instance >> >> (let [x (blah) y (bim) ] >> (if (condition (y)) (throw ...) >> (let [ z (blob) ] >> )) >> >> which seems a bit ugly. I sort of want a let-with-test or a thrush-with- >> test so something which looks like >> >> (-%?> (init) >> (operator-1 %) (post-condition) >> (operator-2 %) (post-condition) ) >> >> where if I don't have a post condition I could just use 'true'. Then >> this expands to doing a quick '(if (not (postcondition (intermedia- >> result)))) throw...) >> >> but that's a crazy thing to want. So curious how you all tackle this. >> >> Thank you all for your consideration. And apologies again if this is >> covered elsewhere or I should have asked in a different forum. >> >> Best, >> >> Paul > > -- > 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. -- 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.
