Clojure's (read-string) is really useful.
eg.
(read-string "{:a 1 :b 2} {:c 3 :d 4} [1 2 3]")
will give me the first object, the {:a 1 :b 2}
But how can I get the rest of string ie. "{:c 3 :d 4} [1 2 3]"
What's the reader equivalent of rest or drop ?
You can wrap the string in a StringReader, then wrap that in a PushbackReader, then read from that reader multiple times.
NB. the example below uses clojure.edn/read, as that is an edn-only reader meant for dealing with pure data; clojure.core/read is primarily meant for reading code and should never be used with untrusted inputs.
(require '[clojure.edn :as edn])
(def s "{:a 1 :b 2} {:c 3 :d 4} [1 2 3]")
;; Normally one would want to use with-open to close the reader,
;; but here we don't really care and we don't want to accidentally
;; close it before consuming the result:
(let [rdr (java.io.PushbackReader. (java.io.StringReader. s))
sentinel (Object.)] ; ← or just use ::eof as sentinel
(take-while #(not= sentinel %)
(repeatedly #(edn/read {:eof sentinel} rdr))))
;= ({:a 1, :b 2} {:c 3, :d 4} [1 2 3])
ClojureScript version of what should be the accepted answer by https://stackoverflow.com/users/232707/michał-marczyk
(require '[cljs.reader :as rdr])
(require '[cljs.tools.reader.reader-types :as reader-types])
(def s "{:a 1 :b 2} {:c 3 :d 4} [1 2 3]")
(let [pbr (reader-types/string-push-back-reader s)
sentinel ::eof]
(take-while #(not= sentinel %)
(repeatedly #(rdr/read {:eof sentinel} pbr))))
Probably not very idiomatic but straightforward
(->> (str "(" "{:a 1 :b 2} {:c 3 :d 4} [1 2 3]" ")")
(read-string))
then access to individual elements (you can also use brackets)
If you have a list within the string, you can preserve it via options given to read-string-
(def str-list "({:a 1 :b 2} {:c 3 :d 4} [1 2 3])")
(read-string {:read-cond :preserve} str-list)
;;=> ({:a 1 :b 2} {:c 3 :d 4} [1 2 3])
The source for the available options can be found in the doc string the of read function, i.e. (source read)from the REPL.
read-cond has nothing to do with this at all. There are no reader conditionals in any of the example inputs.
:read-cond is too narrow of a name, but it parses the string according to what the question is looking for.