Improve support for typed values

Using new `mkTyped` constructor, not yet supported by home-manager.
dict is also still broken for now.

data/typed.settings

@@ -0,0 +1,10 @@
+[typed]
+empty-dict=@a{sv} {}
+empty-array-dict=@a{sv} []
+just-str=@ms 'hello'
+ui32=uint32 7
+at-u=@u 5
+empty-arr=@a(dd) []
+just-empty-str=@ms ""
+doubletime=uint32 uint32 7
+var-empty-arr=<@ai []>

output/dconf.nix

@@ -334,7 +334,7 @@ with lib.hm.gvariant;
     };
 
     "org/gnome/shell/world-clocks" = {
-      locations = [];
+      locations = mkArray "v" [];
     };
 
     "org/gnome/software" = {

output/typed.nix

@@ -0,0 +1,22 @@
+# Generated via dconf2nix: https://github.com/nix-commmunity/dconf2nix
+{ lib, ... }:
+
+with lib.hm.gvariant;
+
+{
+  dconf.settings = {
+    "typed" = {
+      at-u = mkTyped "u" 5;
+      doubletime = mkUint32 7;
+      empty-arr = mkArray "(dd)" [];
+      empty-array-dict = mkArray "{sv}" [];
+      empty-dict = mkTyped "a{sv}" {
+      };
+      just-empty-str = mkTyped "ms" "";
+      just-str = mkTyped "ms" "hello";
+      ui32 = mkUint32 7;
+      var-empty-arr = mkVariant (mkArray "i" []);
+    };
+
+  };
+}

output/variant.nix

@@ -13,7 +13,7 @@ with lib.hm.gvariant;
       string = mkVariant "#polari";
       true = mkVariant true;
       tuple = mkVariant (mkTuple [ (mkUint32 2) "ABC" ]);
-      typed = mkVariant [];
+      typed = mkVariant (mkArray "i" []);
       uint32 = mkVariant (mkUint32 2);
       variant = mkVariant (mkVariant 7);
     };

src/DConf.hs

@@ -127,13 +127,37 @@ vVariant = fmap V $ bracket "<" ">" value
 vList :: Parsec Text () Value
 vList = fmap L $ bracket "[" "]" $ commaSeparated $ value
 
+-- https://gitlab.gnome.org/GNOME/glib/-/blob/4607dd77a1944c6b29dff1e76c195f28a8ca12af/docs/reference/glib/gvariant-specification-1.0.rst#type-strings
+typeString :: Parsec Text () String
+typeString = baseType <|> containerType
+  where
+    baseType = choice (map string ["b", "y", "n", "q", "i", "u", "x", "t", "h", "d", "s", "o", "g"])
+    containerType = variantType <|> maybeType <|> arrayType <|> tupleType <|> dictEntryType
+    types = many typeString
+    variantType = string "v"
+    arrayType = do
+      a <- string "a"
+      t <- typeString
+      return (a ++ t)
+    maybeType = do
+      m <- string "m"
+      t <- typeString
+      return (m ++ t)
+    tupleType = do
+      tt <- bracket "(" ")" types
+      return ("(" ++ concat tt ++ ")")
+    dictEntryType = bracket "{" "}" $ do
+      k <- baseType
+      v <- typeString
+      return ("{" ++ k ++ v ++ "}")
+
 vTyped :: Parsec Text () Value
 vTyped = do
   _ <- char '@'
-  _ <- anyChar
-  _ <- anyChar
+  t <- typeString
   _ <- spaces
-  value
+  v <- value
+  return (Ty t v)
 
 vJson :: Parsec Text () Value
 vJson = try $ bracket "'" "'" $ do

src/DConf/Data.hs

@@ -21,6 +21,7 @@ data Value = S Text         -- String
            | I64 Int        -- Int64
            | D Double       -- Double
            | T [Value]      -- Tuple of n-arity
+           | Ty String Value -- Typed value
            | L [Value]      -- List of values
            | V Value        -- Variant
            | R [(Text,Value)] -- Record

src/Nix.hs

@@ -57,6 +57,9 @@ renderValue raw = Nix $ renderValue' raw <> ";"
   needsParen (D x) = x < 0
   needsParen (I32 _) = True
   needsParen (T _) = True
+  -- will be rendered as @[]@
+  needsParen (Ty "as" (L [])) = False
+  needsParen (Ty _ _) = True
   needsParen (V _) = True
   needsParen _ = False
 
@@ -77,6 +80,10 @@ renderValue raw = Nix $ renderValue' raw <> ";"
   renderValue' (I64 v) = "mkInt64 " <> T.pack (show v)
   renderValue' (L  xs) = renderList xs
   renderValue' (T  xs) = "mkTuple " <> renderList xs
+  -- In home-manager, @mkValue []@ emits @\@as []@
+  renderValue' (Ty "as" (L [])) = renderList []
+  renderValue' (Ty ('a':t) (L v)) = "mkArray " <> T.pack (show t) <> " " <> renderList v
+  renderValue' (Ty t v) = "mkTyped " <> T.pack (show t) <> " " <> renderItem v -- TODO: add mkTyped to h-m
   renderValue' (V   v) = "mkVariant " <> renderItem v
   renderValue' (Json v) =
     "''\n" <> mkSpaces 8 <> T.strip v <> "\n" <> mkSpaces 6 <> "''"

test/DConf2NixTest.hs

@@ -140,6 +140,17 @@ prop_dconf2nix_tuples :: Property
 prop_dconf2nix_tuples =
   withTests (10 :: TestLimit) dconf2nixTuples
 
+dconf2nixTyped :: Property
+dconf2nixTyped =
+  let input  = "data/typed.settings"
+      output = "output/typed.nix"
+      root   = Root T.empty
+  in  baseProperty input output root
+
+prop_dconf2nix_typed :: Property
+prop_dconf2nix_typed =
+  withTests (10 :: TestLimit) dconf2nixTyped
+
 dconf2nixUnicode :: Property
 dconf2nixUnicode =
   let input  = "data/unicode.settings"