gnu: Add ocaml-jsonm.

* gnu/packages/ocaml.scm (ocaml-jsonm): New variable.

gnu/packages/ocaml.scm

@@ -1642,3 +1642,31 @@ (define-public ocaml-uutf
 Functions are also provided to fold over the characters of UTF encoded OCaml
 string values and to directly encode characters in OCaml Buffer.t values.")
     (license license:isc)))
+
+(define-public ocaml-jsonm
+  (package
+    (name "ocaml-jsonm")
+    (version "1.0.0")
+    (source (origin
+              (method url-fetch)
+              (uri (string-append "http://erratique.ch/software/jsonm/releases/"
+                                  "jsonm-" version ".tbz"))
+              (sha256
+                (base32
+                  "1v3ln6d965lplj28snjdqdqablpp1kx8bw2cfx0m6i157mqyln62"))))
+    (build-system ocaml-build-system)
+    (arguments `(#:tests? #f
+                 #:build-flags (list "build")
+                 #:phases
+                 (modify-phases %standard-phases
+                   (delete 'configure))))
+    (native-inputs `(("opam" ,opam)
+                     ("topkg" ,ocaml-topkg)))
+    (propagated-inputs `(("uutf" ,ocaml-uutf)
+                         ("cmdliner" ,ocaml-cmdliner)))
+    (home-page "http://erratique.ch/software/jsonm")
+    (synopsis "Non-blocking streaming JSON codec for OCaml")
+    (description "Jsonm is a non-blocking streaming codec to decode and encode
+the JSON data format.  It can process JSON text without blocking on IO and
+without a complete in-memory representation of the data.")
+    (license license:isc)))