I am writing my first clojure program, and want to read lines from stdin.
When I try this:
(doall (map #(println %) (line-seq *in*)))
I get this exception:
Exception in thread "main" java.lang.ClassCastException: clojure.lang.LineNumberingPushbackReader cannot be cast to java.io.BufferedReader (test.clj:0)
I get the same results in version 1.0 and 1.1
So how do I convert *in*
into a seq I can iterate over? I would have thought that this is common enough that *in*
itself would be iterable, but that does not work either - if I try to use it directly I get:
java.lang.IllegalArgumentException: Don't know how to create ISeq from: clojure.lang.LineNumberingPushbackReader (NO_SOURCE_FILE:0)
Also, are there any examples of doing general file handling in clojure?
Try wrapping *in*
in a java.io.BufferedReader
. And also use doseq
instead of doall
, as devstopfix pointed out:
(doseq [ln (line-seq (java.io.BufferedReader. *in*))]
(println ln))
Note that line-seq
is documented to require a BufferedReader
as its source.