gnu: Add emacs-haskell-snippets.

* gnu/packages/emacs-xyz.scm (emacs-haskell-snippets): New variable.

gnu/packages/emacs-xyz.scm

@@ -21965,3 +21965,40 @@ enables modal editing and composition of commands, too.  It combines ideas of
 other Editors like Vim or Kakoune and tries to align them with regular Emacs
 conventions.")
     (license license:gpl3+)))
+
+(define-public emacs-haskell-snippets
+  ;; The commit below is 5 commits ahead of release, and includes a build fix.
+  (let ((commit "07b0f460b946fd1be26c29652cb0468b47782f3a"))
+    (package
+      (name "emacs-haskell-snippets")
+      (version (git-version "0.1.0" "0" commit))
+      (source
+       (origin
+         (method git-fetch)
+         (uri
+          (git-reference
+           (url "https://github.com/haskell/haskell-snippets")
+           (commit commit)))
+         (file-name (git-file-name name version))
+         (sha256
+          (base32 "0a7y3awi9hcyahggf0ghsdwvsmrhr9yq634wy9lkqjzrm2hqj0ci"))))
+      (build-system emacs-build-system)
+      (arguments
+       `(#:phases
+         (modify-phases %standard-phases
+           (add-after 'install 'install-snippets
+             (lambda* (#:key outputs #:allow-other-keys)
+               (let* ((out (assoc-ref outputs "out"))
+                      (snippets
+                       (string-append
+                        out "/share/emacs/site-lisp/snippets/haskell-mode")))
+                 (mkdir-p snippets)
+                 (copy-recursively "snippets/haskell-mode" snippets)
+                 #t))))))
+      (propagated-inputs
+       `(("emacs-yasnippet" ,emacs-yasnippet)))
+      (home-page "https://github.com/haskell/haskell-snippets")
+      (synopsis "Official collection of YASnippet Haskell snippets for Emacs")
+      (description "Haskell-Snippets is a collection of YASnippet Haskell
+snippets for Emacs.")
+      (license license:expat))))