summaryrefslogtreecommitdiffstats
path: root/krebs/4lib/dns.nix
diff options
context:
space:
mode:
authorlassulus <lass@aidsballs.de>2015-07-28 22:37:28 +0200
committerlassulus <lass@aidsballs.de>2015-07-28 23:23:26 +0200
commit1bf670270c1e87900a908f7e9b949b5502158f4f (patch)
tree3a89e86813805e0d6075d3b01497d681602b45cd /krebs/4lib/dns.nix
parentfa175ca26e533b62f3afc11709ef1689647c558c (diff)
parent06cb4d25ef40773e2cc516e50a9aeec6cbe1d0a8 (diff)
Merge remote-tracking branch 'cd/master' into newmaster2
Diffstat (limited to 'krebs/4lib/dns.nix')
-rw-r--r--krebs/4lib/dns.nix31
1 files changed, 31 insertions, 0 deletions
diff --git a/krebs/4lib/dns.nix b/krebs/4lib/dns.nix
new file mode 100644
index 000000000..b2cf3c24c
--- /dev/null
+++ b/krebs/4lib/dns.nix
@@ -0,0 +1,31 @@
+{ lib, ... }:
+
+let
+ listset = import ./listset.nix { inherit lib; };
+in
+
+with builtins;
+with lib;
+
+rec {
+ # label = string
+
+ # TODO does it make sense to have alias = list label?
+
+ # split-by-provider :
+ # [[label]] -> tree label provider -> listset provider alias
+ split-by-provider = as: providers:
+ foldl (m: a: listset.insert (provider-of a providers) a m) {} as;
+
+ # provider-of : alias -> tree label provider -> provider
+ # Note that we cannot use tree.get here, because path can be longer
+ # than the tree depth.
+ provider-of = a:
+ let
+ go = path: tree:
+ if typeOf tree == "string"
+ then tree
+ else go (tail path) tree.${head path};
+ in
+ go (reverseList (splitString "." a));
+}