On Mon, Jul 18, 2011 at 5:41 PM, Andreas Kostler
<andreas.koestler.le...@gmail.com> wrote:
> Ups, I'm not aware of that thread...I just found a more general threading
> operator handy sometimes.
> I do kinda agree that we shouldn't necessarily encourage threading in
> arbitrary positions.
> However, I can't quite follow your second argument.
> While it does mean two different things, I don't see the problem with that.
> We could use _ instead of :? to indicate we don't care about the 'meaning'.
But _ means "don't care" by convention in Clojure, for values that are
ignored...
The issue is about bindings and immutability: foo should mean the same
value throughout an expression - that's kind of fundamental to Clojure
(IMO). With your macro (and the previous examples introduced by
others), some arbitrary symbol changes its meaning in each consecutive
form without any marker for lexical or dynamic binding... so it's
behaving like a mutable iterator or loop variable :(
With only a couple more characters you can already do what you need
without a new macro:
(-> "x"
(#(str "y" % "z"))
(#(str "a" % "b"))
println)
There's also the possibility of mixing -> and ->> to splice in first
arg / last arg threading. There was a great blog post about this
recently but I can't find it (-> and ->> are remarkably hard to search
for on Google!)...
--
Sean A Corfield -- (904) 302-SEAN
An Architect's View -- http://corfield.org/
World Singles, LLC. -- http://worldsingles.com/
Railo Technologies, Inc. -- http://www.getrailo.com/
"Perfection is the enemy of the good."
-- Gustave Flaubert, French realist novelist (1821-1880)
--
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
