Remove unnecessary indent for list comprehensions in do blocks

CHANGELOG.md

@@ -1,3 +1,7 @@
+## Unreleased
+
+* Remove unnecessary indentation from list comprehensions
+
 ## Ormolu 0.7.5.0
 
 * Switched to `ghc-lib-parser-9.10`, with the following new syntactic features/behaviors:

data/examples/declaration/value/function/comprehension/transform-monad-out.hs

@@ -5,14 +5,14 @@ quux' xs ys =
   [ ( x,
       y
     )
-    | x <- xs,
-      y <- ys,
-      then group by
-        -- First comment
-        ( x
-            + y
-        )
-      using
-        -- Second comment
-        groupWith -- Third comment
+  | x <- xs,
+    y <- ys,
+    then group by
+      -- First comment
+      ( x
+          + y
+      )
+    using
+      -- Second comment
+      groupWith -- Third comment
   ]

data/examples/declaration/value/function/comprehension/transform-multi-line1-out.hs

@@ -4,9 +4,9 @@ foo' xs ys =
   [ ( x,
       y
     )
-    | x <- xs,
-      y <- ys,
-      then
-        -- First comment
-        reverse -- Second comment
+  | x <- xs,
+    y <- ys,
+    then
+      -- First comment
+      reverse -- Second comment
   ]

data/examples/declaration/value/function/comprehension/transform-multi-line2-out.hs

@@ -4,13 +4,13 @@ bar' xs ys =
   [ ( x,
       y
     )
-    | x <- xs,
-      y <- ys,
-      then
-        -- First comment
-        sortWith
-      by
-        ( x
-            + y -- Second comment
-        )
+  | x <- xs,
+    y <- ys,
+    then
+      -- First comment
+      sortWith
+    by
+      ( x
+          + y -- Second comment
+      )
   ]

data/examples/declaration/value/function/comprehension/transform-multi-line3-out.hs

@@ -4,9 +4,9 @@ baz' xs ys =
   [ ( x,
       y
     )
-    | x <- xs,
-      y <- ys,
-      then group using
-        -- First comment
-        permutations -- Second comment
+  | x <- xs,
+    y <- ys,
+    then group using
+      -- First comment
+      permutations -- Second comment
   ]

data/examples/declaration/value/function/comprehension/transform-multi-line4-out.hs

@@ -4,14 +4,14 @@ quux' xs ys =
   [ ( x,
       y
     )
-    | x <- xs,
-      y <- ys,
-      then group by
-        -- First comment
-        ( x
-            + y
-        )
-      using
-        -- Second comment
-        groupWith -- Third comment
+  | x <- xs,
+    y <- ys,
+    then group by
+      -- First comment
+      ( x
+          + y
+      )
+    using
+      -- Second comment
+      groupWith -- Third comment
   ]

data/examples/declaration/value/function/list-comprehensions-out.hs

@@ -4,26 +4,31 @@ bar x y = [(a, b) | a <- x, even a, b <- y, a != b]
 
 barbaz x y z w =
   [ (a, b, c, d) -- Foo
-    | a <-
-        x, -- Bar
-      b <- y, -- Baz
-      any even [a, b],
-      c <-
-        z
-          * z ^ 2, -- Bar baz
-      d <-
-        w
-          + w, -- Baz bar
-      all
-        even
-        [ a,
-          b,
-          c,
-          d
-        ]
+  | a <-
+      x, -- Bar
+    b <- y, -- Baz
+    any even [a, b],
+    c <-
+      z
+        * z ^ 2, -- Bar baz
+    d <-
+      w
+        + w, -- Baz bar
+    all
+      even
+      [ a,
+        b,
+        c,
+        d
+      ]
   ]
 
 a = do
+  d <-
+    [ x + 1
+    | x <- b
+    ]
+
   [ c
     | c <- d
     ]

data/examples/declaration/value/function/list-comprehensions.hs

@@ -22,5 +22,10 @@ barbaz x y z w = [
   ]
 
 a = do
+  d <-
+    [ x + 1
+      | x <- b
+        ]
+
   [ c
       | c <- d ]

data/examples/declaration/value/function/parallel-comprehensions-complex-out.hs

@@ -10,26 +10,26 @@ baz x y z w =
       i,
       j
     )
-    | a <- -- Foo 1
-        x, -- Foo 2
-      b <- -- Bar 1
-        y, -- Bar 2
+  | a <- -- Foo 1
+      x, -- Foo 2
+    b <- -- Bar 1
+      y, -- Bar 2
+    a
+      `mod` b -- Value
+      == 0
+  | c <- -- Baz 1
+      z
+        * z -- Baz 2
+        -- Baz 3
+  | d <- w -- Other
+  | e <- x * x -- Foo bar
+  | f <- -- Foo baz 1
+      y + y -- Foo baz 2
+  | h <- z + z * w ^ 2 -- Bar foo
+  | i <- -- Bar bar 1
       a
-        `mod` b -- Value
-        == 0
-    | c <- -- Baz 1
-        z
-          * z -- Baz 2
-          -- Baz 3
-    | d <- w -- Other
-    | e <- x * x -- Foo bar
-    | f <- -- Foo baz 1
-        y + y -- Foo baz 2
-    | h <- z + z * w ^ 2 -- Bar foo
-    | i <- -- Bar bar 1
-        a
-          + b, -- Bar bar 2
-          -- Bar bar 3
-      j <- -- Bar baz 1
-        a + b -- Bar baz 2
+        + b, -- Bar bar 2
+        -- Bar bar 3
+    j <- -- Bar baz 1
+      a + b -- Bar baz 2
   ]

src/Ormolu/Printer/Meat/Declaration/Value.hs

@@ -443,7 +443,7 @@ p_stmt' s placer render = \case
           | isOneLineSpan (mkSrcSpan (srcSpanEnd loc) (srcSpanStart l)) = placer (unLoc f)
           | otherwise = Normal
     switchLayout [loc, l] $
-      placeHanging placement (located f (render s))
+      placeHanging placement (located f (render N))
   ApplicativeStmt {} -> notImplemented "ApplicativeStmt" -- generated by renamer
   BodyStmt _ body _ _ -> located body (render s)
   LetStmt _ binds -> do
@@ -851,6 +851,9 @@ p_hsExpr' isApp s = \case
     space
     located hswc_body p_hsType
 
+-- | Print a list comprehension.
+--
+-- BracketStyle should be N except in a do-block, which must be S or else it's a parse error.
 p_listComp :: BracketStyle -> GenLocated SrcSpanAnnL [ExprLStmt GhcPs] -> R ()
 p_listComp s es = sitcc (vlayout singleLine multiLine)
   where
@@ -860,17 +863,18 @@ p_listComp s es = sitcc (vlayout singleLine multiLine)
       txt "]"
     multiLine = do
       txt "[" >> space
-      sitcc body
-      newline
-      inciIf (s == S) (txt "]")
+      (if s == S then sitcc else id) $ do
+        body
+        newline
+        txt "]"
 
     body = located es p_body
     p_body xs = do
       let (stmts, yield) =
             case xs of
               [] -> error $ "list comprehension unexpectedly had no expressions"
               _ -> (init xs, last xs)
-      located yield p_stmt
+      sitcc $ located yield p_stmt
       breakpoint
       txt "|"
       space