How do I convert a LazySeq which is a list of lists into a string that has the exact same structure and parantheses?
(def my-list (lazy-seq '((a b 0 1 x y) (a b 0 4 x y) (a b 0 3 x y) )))
(def string-list (print-to-string my-list ))
string-list
;; should return "((a b 0 1 x y) (a b 0 4 x y) (a b 0 3 x y) ))"
;; but returns "clojure.lang.LazySeq@72251662"
If you want to keep the data as they are (or at least do your best with it), don't use str, but use pr-str. It might make no difference for simple things, but it will for more complex data structures.
E.g
user=> (pr-str (lazy-seq '((a b 0 1 x y) (a b 0 4 x y) (a b 0 3 x y) )))
"((a b 0 1 x y) (a b 0 4 x y) (a b 0 3 x y))"
pr and @leetwinski mentioned print. The difference was the subject of stackoverflow.com/questions/21136766/….for lazy sequences you can use print-str, which is alike simple print but writes the result to string.
user> (print-str my-list)
;;=> "((a b 0 1 x y) (a b 0 4 x y) (a b 0 3 x y))"
but beware, it obviously realizes the collection, and in case of infinite seq it would hang forever.
also you can override the print behaviour for any data type you want:
(defmethod print-method clojure.lang.LazySeq [data ^java.io.Writer w]
(let [[firsts] (split-at 10 data)]
(if (= 10 (count firsts))
(.write w (str (seq firsts) " :: more"))
(.write w (str (seq firsts))))))
user> (print-str (lazy-seq (range 1000)))
;;=> "(0 1 2 3 4 5 6 7 8 9) :: more"
(str my-list)