From 5973a46a752db79b4da746c5b6fcf3c6e37ff98b Mon Sep 17 00:00:00 2001
From: zimbatm <zimbatm@zimbatm.com>
Date: Wed, 22 Jul 2020 11:29:59 +0200
Subject: [PATCH] oops, add the flattenTree.nix file

---
 flattenTree.nix | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 flattenTree.nix

diff --git a/flattenTree.nix b/flattenTree.nix
new file mode 100644
index 0000000..a535f86
--- /dev/null
+++ b/flattenTree.nix
@@ -0,0 +1,35 @@
+tree:
+let
+  op = sum: path: val:
+    let
+      pathStr = builtins.concatStringsSep "_" path;
+    in
+    if (builtins.typeOf val) != "set" then
+    # ignore that value
+    # builtins.trace "${pathStr} is not of type set"
+      sum
+    else if val ? type && val.type == "derivation" then
+    # builtins.trace "${pathStr} is a derivation"
+    # we used to use the derivation outPath as the key, but that crashes Nix
+    # so fallback on constructing a static key
+      (sum // {
+        "${pathStr}" = val;
+      })
+    else if val ? recurseForDerivations && val.recurseForDerivations == true then
+    # builtins.trace "${pathStr} is a recursive"
+    # recurse into that attribute set
+      (recurse sum path val)
+    else
+    # ignore that value
+    # builtins.trace "${pathStr} is something else"
+      sum
+  ;
+
+  recurse = sum: path: val:
+    builtins.foldl'
+      (sum: key: op sum (path ++ [ key ]) val.${key})
+      sum
+      (builtins.attrNames val)
+  ;
+in
+recurse { } [ ] tree