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Diffstat (limited to '4lib/krebs/dns.nix')
-rw-r--r-- | 4lib/krebs/dns.nix | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/4lib/krebs/dns.nix b/4lib/krebs/dns.nix new file mode 100644 index 0000000..b2cf3c2 --- /dev/null +++ b/4lib/krebs/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)); +} |