feat(emacs): Install prescient & ivy-prescient

These packages are not in nixpkgs yet (will most likely be added after
the next MELPA import), so they're added here manually.

As both originate from the same source they're added to the same
derivation here by using a custom recipe.

1 files changed, 18 insertions, 1 deletions

diff --git a/emacs.nix b/emacs.nix
index a3e89d37fc..4507ea1646 100644
--- a/emacs.nix
+++ b/emacs.nix
@@ -71,6 +71,23 @@ eglot = with pkgs; emacsPackagesNg.melpaBuild rec {
   };
 };
 
+# prescient & prescient-ivy provide better filtering in ivy/counsel
+prescient = with pkgs; emacsPackagesNg.melpaBuild {
+  pname = "prescient";
+  version = "20180611";
+
+  src = fetchFromGitHub {
+    owner  = "raxod502";
+    repo   = "prescient.el";
+    rev    = "19a2c6b392ca6130dbbcf70cba57ee34d64fe50c";
+    sha256 = "136q785lyhpgyaiysyq4pw11l83sa9h3q57v6papx813gf7rb7v7";
+  };
+
+  recipeFile = writeText "prescient-recipe" ''
+    (prescient :files ("prescient.el" "ivy-prescient.el"))
+  '';
+};
+
 in emacsWithPackages(epkgs:
   # Pinned packages (from unstable):
   (with pkgs; with lib; attrValues pinnedEmacs) ++
@@ -129,5 +146,5 @@ in emacsWithPackages(epkgs:
   ]) ++
 
   # Custom packaged Emacs packages:
-  [ sly sly-company nix-mode eglot pkgs.notmuch ]
+  [ sly sly-company nix-mode eglot prescient pkgs.notmuch ]
 )