Yeah, doto is a handy complement to ->. I forgot about doto, and
there's a place some code which I'll use now. Thanks Mark!
Kev
On Jan 13, 6:38 am, "Mark Volkmann" <r.mark.volkm...@gmail.com> wrote:
> On Mon, Jan 12, 2009 at 11:15 AM, Michael Reid <kid.me...@gmail.com> wrote:
>
> > On Sun, Jan 11, 2009 at 9:12 PM, Mark Triggs <mark.h.tri...@gmail.com>
> > wrote:
>
> >> I've also found this useful for accessing members in nested maps. For
> >> example:
>
> >> (let [me {:person {:name {:first "Mark"
> >> :last "Triggs"}
> >> :email "mark.h.tri...@gmail.com"}}]
> >> (-> me :person :name :first))
>
> >> => "Mark"
>
> >> On Jan 12, 1:04 pm, kkw <kevin.k....@gmail.com> wrote:
> >>> One use I've found for -> (though there are others I haven't come to
> >>> appreciate yet) is when I have something like:
> >>> (f1 (f2 (f3 (f4 x))))
>
> >>> which can be re-written as
> >>> (-> x f4 f3 f2 f1)
>
> >>> I find the latter expression easier to read.
>
> >>> Kev
>
> >>> On Dec 30 2008, 2:49 pm, wubbie <sunj...@gmail.com> wrote:
>
> >>> > Very criptic for newbie.
> >>> > What does "Threads the expr through the forms." mean?
> >>> > Does it create a thread to execute?
>
> >>> > thanks
> >>> > sun
>
> >>> > On Dec 29, 10:07 pm, Paul Barry <pauljbar...@gmail.com> wrote:
>
> >>> > > You can look up the documentation for a function/macro interactively
> >>> > > from the repl:
>
> >>> > > user=> (doc ->)
> >>> > > -------------------------
> >>> > > clojure.core/->
> >>> > > ([x form] [x form & more])
> >>> > > Macro
> >>> > > Threads the expr through the forms. Inserts x as the
> >>> > > second item in the first form, making a list of it if it is not a
> >>> > > list already. If there are more forms, inserts the first form as the
> >>> > > second item in second form, etc.
> >>> > > nil
>
> >>> > > On Dec 29, 8:27 pm, wubbie <sunj...@gmail.com> wrote:
>
> >>> > > > Hi all,
>
> >>> > > > Looking intoants.clj, I came across
> >>> > > > (defn place [[x y]]
> >>> > > > (-> world (nth x) (nth y)))
>
> >>> > > > What -> mean here?
>
> >>> > > > thanks
> >>> > > > sun
>
> > I initially stumbled on what -> is good for. But over time it makes
> > more sense. I like to think of it as similar to this construct, which
> > you often see in the Java world:
>
> > Object result = object.doSomething().doSomethingElse().andMoreThings();
>
> > Of course the doSomethings could also be get*s() or what-have-you.
>
> While we're on this topic, don't forget the closely related doto
> function which calls many functions on the same object, unlike ->
> which calls many functions on the result of the previous function.
> Here's the example from the doc string.
>
> (doto (new java.util.HashMap) (.put "a" 1) (.put "b" 2))
>
> --
> R. Mark Volkmann
> Object Computing, Inc.
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