From cf2654b2e0dedd31c6ec14458953c85530db8cec Mon Sep 17 00:00:00 2001
From: Eric Sagnes <eric.sagnes@gmail.com>
Date: Mon, 7 Nov 2016 08:34:06 +0900
Subject: either type: improve merge function

---
 lib/types.nix | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

(limited to 'lib/types.nix')

diff --git a/lib/types.nix b/lib/types.nix
index 26523f59f25..9366d394da7 100644
--- a/lib/types.nix
+++ b/lib/types.nix
@@ -333,7 +333,15 @@ rec {
       name = "either";
       description = "${t1.description} or ${t2.description}";
       check = x: t1.check x || t2.check x;
-      merge = mergeOneOption;
+      merge = loc: defs:
+        let
+          defList = map (d: d.value) defs;
+        in
+          if   all (x: t1.check x) defList
+               then t1.merge loc defs
+          else if all (x: t2.check x) defList
+               then t2.merge loc defs
+          else mergeOneOption loc defs;
       typeMerge = f':
         let mt1 = t1.typeMerge (elemAt f'.wrapped 0).functor;
             mt2 = t2.typeMerge (elemAt f'.wrapped 1).functor;
-- 
cgit 1.4.1