Remove unnecessary indentation from list comprehensions

tweag · Jun 12, 2024 · 5c816de · 5c816de
1 parent 27ec3fb
commit 5c816de
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Showing 12 changed files with 157 additions and 122 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -6,6 +6,9 @@
 * Don't require a trailing newline in `.ormolu` files. [Issue
   1122](https://github.com/tweag/ormolu/issues/1122).
 
+* Remove unnecessary indentation from list comprehensions. [Issue
+  966](https://github.com/tweag/ormolu/issues/966).
+
 ## Ormolu 0.7.5.0
 
 * Switched to `ghc-lib-parser-9.10`, with the following new syntactic features/behaviors:

diff --git a/data/examples/declaration/value/function/comprehension/transform-monad-out.hs b/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
   ]
diff --git a/data/examples/declaration/value/function/comprehension/transform-multi-line1-out.hs b/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
   ]
diff --git a/data/examples/declaration/value/function/comprehension/transform-multi-line2-out.hs b/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
+      )
   ]
diff --git a/data/examples/declaration/value/function/comprehension/transform-multi-line3-out.hs b/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
   ]
diff --git a/data/examples/declaration/value/function/comprehension/transform-multi-line4-out.hs b/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
   ]
diff --git a/data/examples/declaration/value/function/list-comprehensions-out.hs b/data/examples/declaration/value/function/list-comprehensions-out.hs
@@ -4,35 +4,40 @@ 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
     ]
 
 trans =
   [ x
-    | x <- xs,
-      then
-        reverse,
-      then
-        reverse
+  | x <- xs,
+    then
+      reverse,
+    then
+      reverse
   ]
diff --git a/data/examples/declaration/value/function/list-comprehensions.hs b/data/examples/declaration/value/function/list-comprehensions.hs
@@ -22,6 +22,11 @@ barbaz x y z w = [
   ]
 
 a = do
+  d <-
+    [ x + 1
+      | x <- b
+        ]
+
   [ c
       | c <- d ]
 

diff --git a/data/examples/declaration/value/function/parallel-comprehensions-complex-out.hs b/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
   ]
diff --git a/expected-failures/hlint.txt b/expected-failures/hlint.txt
@@ -14,8 +14,8 @@ src/Extension.hs
   Please, consider reporting the bug.
 src/Hint/Bracket.hs
 @@ -265,8 +265,11 @@
-                 let y = noLocA $ HsApp EpAnnNotUsed a1 (nlHsPar a2),
-                 let r = Replace Expr (toSSA e) [("a", toSSA a1), ("b", toSSA a2)] "a (b)"
+               let y = noLocA $ HsApp EpAnnNotUsed a1 (nlHsPar a2),
+               let r = Replace Expr (toSSA e) [("a", toSSA a1), ("b", toSSA a2)] "a (b)"
              ]
 -         ++ [ (suggest "Redundant bracket" (reLoc x) (reLoc y) [r]) {ideaSpan -- Special case of (v1 . v2) <$> v3
 -                                                                     = locA locPar}
@@ -24,9 +24,9 @@ src/Hint/Bracket.hs
 +                  =
 +                    locA locPar
 +                }
-               | L _ (OpApp _ (L locPar (HsPar _ _ o1@(L locNoPar (OpApp _ _ (isDot -> True) _)) _)) o2 v3) <- [x],
-                 varToStr o2 == "<$>",
-                 let y = noLocA (OpApp EpAnnNotUsed o1 o2 v3) :: LHsExpr GhcPs,
+             | L _ (OpApp _ (L locPar (HsPar _ _ o1@(L locNoPar (OpApp _ _ (isDot -> True) _)) _)) o2 v3) <- [x],
+               varToStr o2 == "<$>",
+               let y = noLocA (OpApp EpAnnNotUsed o1 o2 v3) :: LHsExpr GhcPs,
 
   Formatting is not idempotent.
   Please, consider reporting the bug.
diff --git a/src/Ormolu/Printer/Meat/Declaration/Data.hs b/src/Ormolu/Printer/Meat/Declaration/Data.hs
@@ -239,8 +239,8 @@ p_conDecl singleRecCon ConDeclH98 {..} =
 
     conNameWithContextSpn =
       [ RealSrcSpan real Strict.Nothing
-        | EpaSpan (RealSrcSpan real _) <-
-            mapMaybe (matchAddEpAnn AnnForall) con_ext
+      | EpaSpan (RealSrcSpan real _) <-
+          mapMaybe (matchAddEpAnn AnnForall) con_ext
       ]
         <> fmap getLocA con_ex_tvs
         <> maybeToList (fmap getLocA con_mb_cxt)