23.05: New way to get the list of tier1 systems

[nixos-qemu-vm-isolation] / lib / tier1.nix

diff --git a/lib/tier1.nix b/lib/tier1.nix
new file mode 100644 (file)
index 0000000..beb5e35
--- /dev/null
+++ b/lib/tier1.nix
@@ -0,0 +1,28 @@
+# Since 168b926435628cb06c4a8cb0f3e6f69f141529f1, we do shenanigans to get the tier1 list.  :(
+
+nixpkgs:
+
+let
+  inherit (nixpkgs) lib;
+  inherit (lib) elemAt foldl' isList splitString;
+  inherit (builtins) readFile;
+
+  lines = splitString "\n";
+
+  between = start: stop: list:
+    let
+      step = state: x:
+        if isNull state && x == start then
+          [ ]
+        else if isList state then
+          if x == stop then { result = state; } else state ++ [ x ]
+        else
+          state;
+    in (foldl' step null list).result;
+
+  strip-quotes = x: elemAt (builtins.match "  \"(.*)\"" x) 0;
+
+  systems-file = "${nixpkgs}/lib/systems/flake-systems.nix";
+
+in map strip-quotes
+(between "  # Tier 1" "  # Tier 2" (lines (readFile systems-file)))