gnu: Add emacs-rg.

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

Signed-off-by: Efraim Flashner <efraim@flashner.co.il>

gnu/packages/emacs-xyz.scm

@@ -135,6 +135,7 @@
   #:use-module (gnu packages package-management)
   #:use-module (gnu packages perl)
   #:use-module (gnu packages pdf)
+  #:use-module (gnu packages rust-apps)
   #:use-module (gnu packages scheme)
   #:use-module (gnu packages speech)
   #:use-module (gnu packages xiph)
@@ -2779,6 +2780,43 @@ column by drawing a thin line down the length of the editing window.")
      "This Emacs package allows managing multiple grep buffers.")
     (license license:gpl3+)))
 
+(define-public emacs-rg
+  (package
+    (name "emacs-rg")
+    (version "1.8.1")
+    (source
+     (origin
+       (method git-fetch)
+       (uri (git-reference
+             (url "https://github.com/dajva/rg.el.git")
+             (commit version)))
+       (file-name (git-file-name name version))
+       (sha256
+        (base32 "0k7x5z7mh9flwih35cqy8chs54rack3nswdcpw5wcpgv6xim227y"))))
+    (build-system emacs-build-system)
+    (arguments
+     '(#:phases
+       (modify-phases %standard-phases
+         (add-after 'unpack 'hardcode-rg-path
+           ;; Hardcode the path to ripgrep.
+           (lambda _
+             (let ((file "rg.el"))
+               (chmod file #o644)
+               (emacs-substitute-sexps file
+                 ("(defcustom rg-executable" (which "rg")))))))))
+    (propagated-inputs
+     `(("emacs-s" ,emacs-s)
+       ("emacs-wgrep" ,emacs-wgrep)))
+    (inputs
+     `(("ripgrep" ,ripgrep)))
+    (home-page "https://rgel.readthedocs.io/en/latest/")
+    (synopsis "Search tool based on @code{ripgrep}")
+    (description
+     "@code{rg} is an Emacs search package based on the @code{ripgrep} command
+line tool.  It allows one to interactively search based on the editing context
+then refine or modify the search results.")
+    (license license:gpl3+)))
+
 (define-public emacs-inf-ruby
   (package
     (name "emacs-inf-ruby")