Add config generation

bsc/garlic/experiments/config.nix

@@ -0,0 +1,61 @@
+let
+  lib = import <nixpkgs/lib>;
+
+  inputParams = {
+    # MPI implementation
+    mpi = [
+      "impi"
+      "mpich"
+    ];
+
+    # Gcc compiler
+    gcc = [
+      "gcc9"
+      "gcc7"
+    ];
+
+    # Additional cflags
+    cflags = [
+      ["-O3" "-fnobugs"]
+      ["-Ofast"]
+    ];
+
+    # Which git branches
+#    branches = [
+#      "mpi+seq"
+#      "seq"
+#    ];
+  };
+
+  apps = [
+    "dummy"
+  ];
+
+  # genAttrSets "a" ["hello" "world"]
+  # [ { a = "hello"; } { a = "world"; } ]
+  genAttrSets = (name: arr: (map (x: {${name}=x; })) arr);
+
+  # addAttrSets "a" [1 2] {e=4;}
+  # [ { a = 1; e = 4; } { a = 2; e = 4; } ]
+  addAttrSets = (name: arr: set: (map (x: set // {${name}=x; })) arr);
+
+  # attrToList {a=1;}
+  # [ { name = "a"; value = 1; } ]
+  attrToList = (set: map (name: {name=name; value=set.${name};} ) (builtins.attrNames set));
+
+  # mergeConfig [{e=1;}] {name="a"; value=[1 2]
+  # [ { a = 1; e = 1; } { a = 2; e = 1; } ]
+  mergeConfig = (arr: new: lib.flatten ( map (x: addAttrSets new.name new.value x) arr));
+
+  # genConfigs {a=[1 2]; b=[3 4];}
+  # [ { a = 1; b = 3; } { a = 1; b = 4; } { a = 2; b = 3; } { a = 2; b = 4; } ]
+  genConfigs = (config: lib.foldl mergeConfig [{}] (attrToList config));
+
+
+  # Generates all configs from inputParams
+  allConfigs = (genConfigs inputParams);
+
+in 
+  {
+    inherit allConfigs;
+  }