Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
443 views
in Technique[技术] by (71.8m points)

lambda - threading macro -> with anonymous functions

I understand the `-> theading macro in Clojure applies all the provided functions provided to a given argument. However, it doesn't seem to work with anonymous functions. For example:

user> (-> 4 inc inc dec)
5

But:

user> (-> 4 #(+ % 1) #(- % 1) #(+ % 1))

Returns the error:

clojure.lang.Symbol cannot be cast to clojure.lang.IPersistentVector
[Thrown class java.lang.ClassCastException]

If someone knows a way around it would be helpful. Thanks!

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

You can have anonymous functions in Clojure macros. You are having problems, because you are missing some parentheses. :) Your example is edited below.

(-> 4 (#(+ % 1)) (#(- % 1)) (#(+ % 1)))

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...