1 files changed, 32 insertions, 0 deletions
diff --git a/app/Field.hs b/app/Field.hs
new file mode 100644
index 0000000..68baec7
--- /dev/null
+++ b/app/Field.hs
@@ -0,0 +1,32 @@
+module Field
+  ( Field (..),
+    toString,
+    prefix,
+  )
+where
+
+import Data.Aeson qualified as J
+import Data.Aeson.Key qualified as JK
+import Data.Aeson.KeyMap qualified as JM
+import Data.List (intercalate)
+import Data.List.NonEmpty qualified as N
+import Data.Text qualified as T
+
+data Field
+  = Qualified Collection (N.NonEmpty T.Text)
+  | Unqualified (N.NonEmpty T.Text)
+  deriving (Show)
+
+toString :: Field -> String
+toString (Qualified c ks) = intercalate "." (c : map T.unpack (N.toList ks))
+toString (Unqualified ks) = intercalate "." (map T.unpack (N.toList ks))
+
+type Collection = FilePath
+
+prefix :: Field -> J.Value -> J.Value
+prefix (Qualified c ks) = prefix' (T.pack c : N.toList ks)
+prefix (Unqualified ks) = prefix' (N.toList ks)
+
+prefix' :: [T.Text] -> J.Value -> J.Value
+prefix' ks v =
+  foldr ((J.Object .) . JM.singleton) v (map JK.fromText ks)