I almost never use either the `comp` or the `partial` functions. I think it is clearer to either compose the functions like Gary showed, or to use a threading macro (my favorite is the `it->` macro from the Tupelo library <https://github.com/cloojure/tupelo#literate-threading-macro>). Alan
On Thu, Oct 27, 2016 at 8:00 AM, Gary Trakhman <gary.trakh...@gmail.com> wrote: > Comp does its work at run-time, so you have to call functions that return > functions. Threading macros do their work at compile-time, so your form > literally compiles to this: > > > > (clojure.walk/macroexpand-all '(->> (str/split s #"(?<=[a-z])(?=[A-Z])") > (map str/lower-case) > (interpose \-) > str/join > keyword)) > (keyword > (str/join > (interpose \- > (map str/lower-case > (str/split s #"(?<=[a-z])(?=[A-Z])"))))) > > > On Thu, Oct 27, 2016 at 10:56 AM JHacks <jhackswo...@gmail.com> 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`. >> >> -- >> 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. > -- 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.
