I wanted to add the map/cycle sample, then thougt of clojuredocs and here you go:
http://clojuredocs.org/clojure_core/clojure.core/identity On 14 Aug., 00:25, Alan Malloy <a...@malloys.org> wrote: > On Aug 13, 12:45 pm, jaime <xiejianm...@gmail.com> wrote: > > > I found an interesting function "identity" which will do nothing but > > only returns the parameter passed to it. The next minute I came up a > > question: "then what's the purpose of this function?" -- I've tried to > > figure out reasons of existence of "identity". > > > The only reason that I can imagine is this: because we often use > > higher-order functions, these higher-order functions will accept > > functions as its parameters, in such a situation, when we want to use > > a higher-order function but don't want to pass any "real" functions to > > it, then we can use function like "identity" and "identity" here is > > just to fill the role of parameter of higher-order function. > > > Guys, is my guess correct or not? Are there other reasons for > > identity's existence?? Are there other functions for the same purpose? > > One of my favorite uses of identity is for use with partition-by: > > user> (partition-by identity '(a a b a a a a c c d)) > ;; ((a a) (b) (a a a a) (c c) (d)) > > I sometimes speculate that, while identity is plenty useful, if your > program contains the characters "(identity", you probably don't know > how to program. -- 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
