gnu: Add cl-specialization-store.

* gnu/packages/lisp-xyz.scm (cl-specialization-store,
  ecl-specialization-store, sbcl-specialization-store): New variables.

Signed-off-by: Guillaume Le Vaillant <glv@posteo.net>

gnu/packages/lisp-xyz.scm

@@ -6693,6 +6693,45 @@ ability to store all Common Lisp data types into streams.")
 (define-public ecl-cl-store
   (sbcl-package->ecl-package sbcl-cl-store))
 
+(define-public sbcl-specialization-store
+  (let ((commit "8d39a866a6f24986aad3cc52349e9cb2653496f3")
+        (revision "1"))
+    (package
+      (name "sbcl-specialization-store")
+      (version (git-version "0.0.5" revision commit))
+      (source
+       (origin
+         (method git-fetch)
+         (uri (git-reference
+               (url "https://github.com/markcox80/specialization-store")
+               (commit commit)))
+         (file-name (git-file-name "specialization-store" version))
+         (sha256
+          (base32 "0r0bgb46q4gy72l78s7djkxq8ibb4bb3yh9brsry5lih7br8lhi0"))))
+      (build-system asdf-build-system/sbcl)
+      (native-inputs
+       `(("fiveam" ,sbcl-fiveam)))
+      (inputs
+       `(("alexandria" ,sbcl-alexandria)
+         ("introspect-environment" ,sbcl-introspect-environment)))
+      (home-page "https://github.com/markcox80/specialization-store")
+      (synopsis "Different type of generic function for Common Lisp")
+      (description
+       "SPECIALIZATION-STORE system provides a new kind of function, called
+a store function, whose behavior depends on the types of objects passed to the
+function.")
+      (license license:bsd-2))))
+
+(define-public ecl-specialization-store
+  (package
+    (inherit (sbcl-package->ecl-package sbcl-specialization-store))
+    (arguments
+     ;; TODO: Find why the tests get stuck forever; disable them for now.
+     `(#:tests? #f))))
+
+(define-public cl-specialization-store
+  (sbcl-package->cl-source-package sbcl-specialization-store))
+
 (define-public sbcl-cl-gobject-introspection
   (let ((commit "d0136c8d9ade2560123af1fc55bbf70d2e3db539")
         (revision "1"))