I agree 100%. I quite frequently use the style, more than any of the alternatives. It even has a name, "Introduce Explaining Variable":
http://refactoring.com/catalog/extractVariable.html Alan On Sun, Oct 30, 2016 at 7:50 PM, Mikera <mike.r.anderson...@gmail.com> wrote: > On Thursday, 27 October 2016 22:56:42 UTC+8, JHacks wrote: >> >> I have some confusion about how the function `comp` works, especially as >> compared to the threading macro `->>`. >> >> From the book *Clojure Programming* (pages 70-71 of Chapter 2: Functional >> Programming), the following two functions are described as functionally >> equivalent: >> >> (def camel->keyword >> (comp keyword >> str/join >> (partial interpose \-) >> (partial map str/lower-case) >> #(str/split % #"(?<=[a-z])(?=[A-Z])"))) >> >> (defn camel->keyword* >> [s] >> (->> (str/split s #"(?<=[a-z])(?=[A-Z])") >> (map str/lower-case) >> (interpose \-) >> str/join >> keyword)) >> >> Why does the first function, `camel->keyword`, need to use `partial` with >> the >> `map` and `interpose` functions? The second function, `camel->keyword*`, >> does >> not need to use `partial`. >> > > I actually prefer the following style to both of the above: > > (defn camel->keyword* > [s] > (let [words (str/split s #"(?<=[a-z])(?=[A-Z])") > lc-words (map str/lower-case words) > joined-words (str/join "-" lc-words)] > (keyword joined-words))) > > Reasons: > - Your intermediate values are explicitly named, which helps to make the > code self-describing > - It is (marginally) more performant than the composed function case (I > think exactly matches the threading macro) > - You can use the intermediate values in more than one of the following > steps if needed, which can make refactoring / adding new features easier > - The ordering is (to me) more logical as it describes the stages of the > transformation in the order they are performed. > - It is less "Clever". Clever code is generally bad for maintenance and > future understanding. Both functional composition and the > code-transformation effects of the threading macro represent conceptual > overhead that you don't need to pay (in this case). > > > > > -- > 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.
