Take the fixities of lens' operators into account

CHANGELOG.md

@@ -15,7 +15,7 @@
 - HIndent now assumes no extensions are enabled by default ([#728]).
 - All modules except for `HIndent` are now private, and the minimum necessary definitions are exposed from the module ([#729]).
 - HIndent now prints all `do` expressions in a unified style  ([#739]).
-- HIndent now formats operators based on their fixities ([#741]).
+- HIndent now formats operators based on their fixities ([#741], [#742]).
 
 ### Fixed
 
@@ -351,6 +351,7 @@ This version is accidentally pushlished, and is the same as 5.3.3.
 [@uhbif19]: https://github.com/uhbif19
 [@toku-sa-n]: https://github.com/toku-sa-n
 
+[#742]: https://github.com/mihaimaruseac/hindent/pull/742
 [#741]: https://github.com/mihaimaruseac/hindent/pull/741
 [#739]: https://github.com/mihaimaruseac/hindent/pull/739
 [#731]: https://github.com/mihaimaruseac/hindent/pull/731

TESTS.md

@@ -2659,6 +2659,17 @@ f =
     - ffffffffffffffff / -ggggggggggggg
 ```
 
+Lens operators
+
+```haskell
+updateUsr usr =
+  usr
+    & userFirstName .~ "newfirst"
+    & userLastName .~ "newlast"
+    & userEmail .~ "newemail"
+    & userPassword .~ "newpass"
+```
+
 ### Primitive type values
 
 `Char`

hindent.cabal

@@ -41,6 +41,7 @@ library
       HIndent.CommandlineOptions
       HIndent.Config
       HIndent.Error
+      HIndent.Fixity
       HIndent.GhcLibParserWrapper.GHC.Hs
       HIndent.Language
       HIndent.LanguageExtension

src/HIndent/Fixity.hs

@@ -0,0 +1,67 @@
+-- | Operator fixities.
+--
+-- It is very difficult to take operators' fixities into account as fixity
+-- information is not stored in an AST. While `ghc-lib-parser-ex` provides
+-- `fixitiesFromModule`, it is almost useless as operators are usually imported
+-- from other modules.
+--
+-- Ormolu is trying to resolve this issue by examing Hackage, but doing the same
+-- way in HIndent is not so easy.
+module HIndent.Fixity
+  ( fixities
+  ) where
+
+import GHC.Types.Fixity
+import Language.Haskell.GhclibParserEx.Fixity
+
+-- | Operator fixities that HIndent supports.
+fixities :: [(String, Fixity)]
+fixities = baseFixities <> lensFixities
+
+-- | Fixities of operators defined in lens package.
+lensFixities :: [(String, Fixity)]
+lensFixities =
+  concat
+    [ infixr_
+        4
+        [ ".~"
+        , "%~"
+        , "+~"
+        , "-~"
+        , "*~"
+        , "//~"
+        , "^~"
+        , "^^~"
+        , "**~"
+        , "||~"
+        , "<>~"
+        , "&&~"
+        , "<.~"
+        , "?~"
+        , "<?~"
+        , "%@~"
+        , ".@~"
+        ]
+    , infix_
+        4
+        [ ".="
+        , "%="
+        , "+="
+        , "-="
+        , "*="
+        , "//="
+        , "^="
+        , "^^="
+        , "**="
+        , "||="
+        , "<>="
+        , "&&="
+        , "<.="
+        , "?="
+        , "<?="
+        , "%@="
+        , ".@="
+        ]
+    , infixr_ 2 ["<^"]
+    , infixl_ 1 ["&"]
+    ]

src/HIndent/ModulePreprocessing.hs

@@ -18,6 +18,7 @@ import Data.Maybe
 import GHC.Hs
 import GHC.Types.SrcLoc
 import Generics.SYB hiding (GT, typeOf, typeRep)
+import HIndent.Fixity
 import HIndent.GhcLibParserWrapper.GHC.Hs
 import HIndent.ModulePreprocessing.CommentRelocation
 import Language.Haskell.GhclibParserEx.Fixity
@@ -49,7 +50,7 @@ modifyASTForPrettyPrinting m = relocateComments (beforeRelocation m) allComments
 -- | This function modifies the given module AST to apply fixities of infix
 -- operators defined in the 'base' package.
 fixFixities :: HsModule' -> HsModule'
-fixFixities = applyFixities baseFixities
+fixFixities = applyFixities fixities
 
 -- | This function sets an 'LGRHS's end position to the end position of the
 -- last RHS in the 'grhssGRHSs'.

src/HIndent/Pretty.hs

@@ -40,14 +40,14 @@ import GHC.Types.SrcLoc
 import GHC.Unit.Module.Warnings
 import HIndent.Applicative
 import HIndent.Config
+import HIndent.Fixity
 import HIndent.Pretty.Combinators
 import HIndent.Pretty.Import
 import HIndent.Pretty.NodeComments
 import HIndent.Pretty.Pragma
 import HIndent.Pretty.SigBindFamily
 import HIndent.Pretty.Types
 import HIndent.Printer
-import Language.Haskell.GhclibParserEx.Fixity hiding (fixity)
 import Language.Haskell.GhclibParserEx.GHC.Hs.Expr
 import Text.Show.Unicode
 #if MIN_VERSION_ghc_lib_parser(9,6,1)
@@ -1774,7 +1774,7 @@ instance Pretty InfixApp where
             error
               "The number of the sum of operants and operators should be odd."
       prettyOps _ = error "Too short list."
-      findFixity o = fromMaybe defaultFixity $ lookup (varToStr o) baseFixities
+      findFixity o = fromMaybe defaultFixity $ lookup (varToStr o) fixities
       allOperantsAndOperatorsLeftAssoc = reverse $ rhs : op : collect lhs
         where
           collect :: LHsExpr GhcPs -> [LHsExpr GhcPs]