gnu: Add vala-language-server.

* gnu/packages/gnome-xyz.scm (vala-language-server): New variable.

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

gnu/packages/gnome-xyz.scm

@@ -6,6 +6,7 @@
 ;;; Copyright © 2020 Jack Hill <jackhill@jackhill.us>
 ;;; Copyright © 2020 Ekaitz Zarraga <ekaitz@elenq.tech>
 ;;; Copyright © 2020 Tobias Geerinckx-Rice <me@tobias.gr>
+;;; Copyright © 2020 Ryan Prior <rprior@protonmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -585,3 +586,36 @@ dark elements.  It supports GNOME, Unity, Xfce, and Openbox.")
       (description "Papirus is a fork of the icon theme Paper with a lot of new icons
 and a few extra features.")
       (license license:gpl3))))
+
+(define-public vala-language-server
+  (package
+    (name "vala-language-server")
+    ;; Note to maintainer: VLS must be built with a Vala toolchain the same
+    ;; version or newer. Therefore when you update this package you may need
+    ;; to update Vala too.
+    (version "0.48")
+    (source (origin
+              (method git-fetch)
+              (uri (git-reference
+                    (url "https://github.com/benwaffle/vala-language-server.git")
+                    (commit version)))
+              (file-name (git-file-name name version))
+              (sha256
+               (base32 "0chgfpci247skrvsiq1l8cas8sj2z6z42dlarka3df3qwxmh0if0"))))
+    (build-system meson-build-system)
+    (arguments '(#:glib-or-gtk? #t))
+    (inputs
+     `(("glib" ,glib)
+       ("json-glib" ,json-glib)
+       ("jsonrpc-glib" ,jsonrpc-glib)
+       ("libgee" ,libgee)
+       ("vala" ,vala-0.48)))
+    (native-inputs
+     `(("pkg-config" ,pkg-config)))
+    (home-page "https://github.com/benwaffle/vala-language-server")
+    (synopsis "Language server for Vala")
+    (description "The Vala language server is an implementation of the Vala
+language specification for the Language Server Protocol (LSP).  This tool is
+used in text editing environments to provide a complete and integrated
+feature-set for programming Vala effectively.")
+    (license license:lgpl2.1+)))