Move tuple function transformation to Upgrade_0_19

src/ElmFormat/Render/Box.hs

@@ -1063,25 +1063,11 @@ formatExpression' elmVersion context aexpr =
             formatExpression elmVersion context left
 
         AST.Expression.App left args multiline ->
-            case (elmVersion, RA.drop left) of
-                (Elm_0_19_Upgrade, AST.Expression.TupleFunction n) ->
-                    let
-                        forceMultiline =
-                            case (multiline, args) of
-                                (_, []) -> False -- no items; don't split
-                                (AST.FASplitFirst, _) -> True -- all are split
-                                (AST.FAJoinFirst _, [_]) -> False -- only one and it's joined
-                                (AST.FAJoinFirst AST.JoinAll, _) -> False -- all are joined
-                                (AST.FAJoinFirst AST.SplitAll, _:_:_) -> True -- first is joined, but rest are split
-                    in
-                    formatExpression elmVersion context (formatTupleLambda_0_19 n args forceMultiline)
-
-                _ ->
-                    ElmStructure.application
-                      multiline
-                      (formatExpression elmVersion InfixSeparated left)
-                      (fmap (formatPreCommentedExpression elmVersion SpaceSeparated) args)
-                      |> expressionParens SpaceSeparated context
+            ElmStructure.application
+                multiline
+                (formatExpression elmVersion InfixSeparated left)
+                (fmap (formatPreCommentedExpression elmVersion SpaceSeparated) args)
+                |> expressionParens SpaceSeparated context
 
         AST.Expression.If if' elseifs (elsComments, els) ->
             let
@@ -1233,12 +1219,7 @@ formatExpression' elmVersion context aexpr =
             ElmStructure.group True "(" "," ")" multiline $ map (formatCommentedExpression elmVersion SyntaxSeparated) exprs
 
         AST.Expression.TupleFunction n ->
-            case elmVersion of
-                Elm_0_19_Upgrade ->
-                    formatExpression elmVersion context (formatTupleLambda_0_19 n [] False)
-
-                _ ->
-                    line $ keyword $ "(" ++ (List.replicate (n-1) ',') ++ ")"
+            line $ keyword $ "(" ++ (List.replicate (n-1) ',') ++ ")"
 
         AST.Expression.Access expr field ->
             formatExpression elmVersion SpaceSeparated expr -- TODO: does this need a different context than SpaceSeparated?
@@ -1300,54 +1281,6 @@ formatPreCommentedExpression elmVersion context (pre, e) =
     formatCommented' pre' (formatExpression elmVersion context) e'
 
 
-formatTupleLambda_0_19 :: Int -> [(AST.Comments, AST.Expression.Expr)] -> Bool -> AST.Expression.Expr
-formatTupleLambda_0_19 n args forceMultiline =
-    let
-      vars =
-        if n <= 26
-          then fmap (\c -> [c]) (drop (length appliedArgs) $ take n ['a'..'z'])
-          else error (pleaseReport'' "UNEXPECTED TUPLE" "more than 26 elements")
-
-      appliedArgs =
-          take n args
-
-      extraArgs =
-          drop n args
-
-      makeArg varName =
-          ([], noRegion $ AST.Pattern.VarPattern $ AST.LowercaseIdentifier varName)
-
-      makeTupleItem varName =
-          AST.Commented [] (noRegion $ AST.Expression.VarExpr $ AST.Variable.VarRef [] $ AST.LowercaseIdentifier varName) []
-
-      makeInlinedValue (comments, expr) =
-          AST.Commented comments expr []
-
-      tuple =
-          (noRegion $ AST.Expression.Tuple (fmap makeInlinedValue appliedArgs ++ fmap makeTupleItem vars) forceMultiline)
-
-      replacement =
-          case vars of
-              [] ->
-                  tuple
-
-              _ : _ ->
-                  (noRegion $ AST.Expression.Lambda (fmap makeArg vars) [] tuple False)
-    in
-    case extraArgs of
-        [] ->
-            replacement
-
-        _ : _ ->
-            let
-                multiline =
-                    if forceMultiline
-                        then AST.FASplitFirst
-                        else AST.FAJoinFirst AST.JoinAll
-            in
-            noRegion $ AST.Expression.App replacement extraArgs multiline
-
-
 formatRecordLike ::
     (base -> Box) -> (key -> Line) -> String -> (value -> Box)
     -> Maybe (AST.Commented base) -> AST.Sequence (AST.Pair key value)-> AST.Comments -> AST.ForceMultiline

src/ElmFormat/Upgrade_0_19.hs

@@ -10,8 +10,10 @@ import Reporting.Annotation (Located(A))
 
 import qualified Data.Map.Strict as Dict
 import qualified Data.Maybe as Maybe
+import qualified ElmFormat.Version
 import qualified Reporting.Annotation as RA
 import qualified Reporting.Region as Region
+import qualified ReversedList
 
 
 transform :: Expr -> Expr
@@ -90,6 +92,18 @@ transform expr =
 
                 _ -> Nothing
 
+        makeTuple n =
+            let
+                vars =
+                  if n <= 26
+                    then fmap (\c -> [c]) (take n ['a'..'z'])
+                    else error (pleaseReport'' "UNEXPECTED TUPLE" "more than 26 elements")
+            in
+                Lambda
+                    (fmap makeArg vars)
+                    []
+                    (noRegion $ AST.Expression.Tuple (fmap (\v -> Commented [] (makeVarRef v) []) vars) False)
+                    False
     in
     case RA.drop expr of
         VarExpr var ->
@@ -98,6 +112,12 @@ transform expr =
         App (A _ (VarExpr var)) args multiline ->
             Maybe.fromMaybe expr $ fmap (\new -> applyLambda (noRegion new) args multiline) $ replace var
 
+        TupleFunction n ->
+            noRegion $ makeTuple n
+
+        App (A _ (TupleFunction n)) args multiline ->
+            applyLambda (noRegion $ makeTuple n) args multiline
+
         _ ->
             expr
 
@@ -107,6 +127,12 @@ transform expr =
 --
 
 
+pleaseReport'' :: String -> String -> String
+pleaseReport'' what details =
+    "<elm-format-" ++ ElmFormat.Version.asString ++ ": "++ what ++ ": " ++ details ++ " -- please report this at https://github.com/avh4/elm-format/issues >"
+
+
+
 nowhere :: Region.Position
 nowhere =
     Region.Position 0 0
@@ -209,11 +235,30 @@ instance MapExpr LetDeclaration where
           _ -> d
 
 
-inlineVar :: LowercaseIdentifier -> Expr' -> Expr' -> Expr'
-inlineVar name value expr =
+inlineVar :: LowercaseIdentifier -> Bool -> Expr' -> Expr' -> Expr'
+inlineVar name insertMultiline value expr =
+    Maybe.fromMaybe expr $ inlineVar' name insertMultiline value expr
+
+
+inlineVar' :: LowercaseIdentifier -> Bool -> Expr' -> Expr' -> Maybe Expr'
+inlineVar' name insertMultiline value expr =
     case expr of
-        VarExpr (VarRef [] n) | n == name -> value
-        _ -> mapExpr (inlineVar name value) expr
+        VarExpr (VarRef [] n) | n == name -> Just value
+
+        AST.Expression.Tuple terms' multiline ->
+            let
+                step (acc, expand) t@(Commented pre (A _ term) post) =
+                    case inlineVar' name insertMultiline value term of
+                        Nothing -> (ReversedList.push t acc, expand)
+                        Just term' -> (ReversedList.push (Commented pre (noRegion term') post) acc, insertMultiline || expand)
+
+                (terms'', multiline'') = foldl step (ReversedList.empty, multiline) terms'
+            in
+            Just $ AST.Expression.Tuple (ReversedList.toList terms'') multiline''
+
+        -- TODO: handle expanding multiline in contexts other than tuples
+
+        _ -> Just $ mapExpr (inlineVar name insertMultiline value) expr
 
 
 applyLambda :: Expr -> [PreCommented Expr] -> FunctionApplicationMultiline -> Expr
@@ -247,7 +292,7 @@ applyLambda lambda args appMultiline =
 
                 Just mappings ->
                     let
-                        newBody = foldl (\e (name, value) -> mapExpr (inlineVar name value) e) body mappings
+                        newBody = foldl (\e (name, value) -> mapExpr (inlineVar name (appMultiline == FASplitFirst) value) e) body mappings
                         newMultiline =
                             case appMultiline of
                                 FASplitFirst -> FASplitFirst