diff --git a/source/library/Language/Haskell/Brittany/Internal/Components/OpTree.hs b/source/library/Language/Haskell/Brittany/Internal/Components/OpTree.hs
index c008191..c3f18ad 100644
--- a/source/library/Language/Haskell/Brittany/Internal/Components/OpTree.hs
+++ b/source/library/Language/Haskell/Brittany/Internal/Components/OpTree.hs
@@ -99,10 +99,11 @@ balanceOpTree allowUnqualify = \case
             (warns, OpKnown paren locO locC fixity c cs)
           Right t -> (warns, t)
           Left moreWarns ->
-            ( warns
-                ++ [ LayoutWarning ("Fixity of operator not known: " ++ w)
-                   | w <- moreWarns
-                   ]
+            ( (  warns
+              ++ [ LayoutWarning ("Fixity of operator not known: " ++ w)
+                 | w <- moreWarns
+                 ]
+              )
             , x
             )
  where
@@ -255,9 +256,17 @@ hardcodedFixity allowUnqualify = \case
   "!<<."      -> Just $ Fixity NoSourceText 8 InfixL
   ">=>"       -> Just $ Fixity NoSourceText 1 InfixR
   "<=<"       -> Just $ Fixity NoSourceText 1 InfixR
+  "&&&"       -> Just $ Fixity NoSourceText 3 InfixR
+  "<$!>"      -> fixity InfixL 4
 
+  "~"         -> fixity InfixN 4
+  "~~"        -> fixity InfixN 4
   ":~:"       -> Just $ Fixity NoSourceText 4 InfixN
   ":~~:"      -> Just $ Fixity NoSourceText 4 InfixN
+  ":+:"       -> fixity InfixR 5
+  ":*:"       -> fixity InfixR 6
+  ":.:"       -> fixity InfixR 7
+  ":|"        -> fixity InfixR 5
 
   -- non-base from random sources.
   "<|"        -> Just $ Fixity NoSourceText 5 InfixR
@@ -269,7 +278,126 @@ hardcodedFixity allowUnqualify = \case
   ":?"        -> Just $ Fixity NoSourceText 7 InfixN
   ":-"        -> Just $ Fixity NoSourceText 9 InfixR
   ".:"        -> Just $ Fixity NoSourceText 9 InfixR
-  ".="        -> Just $ Fixity NoSourceText 8 InfixR
+  "$!!"       -> fixity InfixR 0
+  "<$!!>"     -> fixity InfixL 4
+
+  -- lens, not complete!
+  "<|"        -> fixity InfixR 5
+  "|>"        -> fixity InfixL 5
+  "%~"        -> fixity InfixR 4
+  ".~"        -> fixity InfixR 4
+  "?~"        -> fixity InfixR 4
+  "<.~"       -> fixity InfixR 4
+  "<?~"       -> fixity InfixR 4
+  "+~"        -> fixity InfixR 4
+  "*~"        -> fixity InfixR 4
+  "-~"        -> fixity InfixR 4
+  "//~"       -> fixity InfixR 4
+  "^~"        -> fixity InfixR 4
+  "^^~"       -> fixity InfixR 4
+  "**~"       -> fixity InfixR 4
+  "||~"       -> fixity InfixR 4
+  "&&~"       -> fixity InfixR 4
+  ".="        -> fixity InfixN 4
+  "%="        -> fixity InfixN 4
+  "?="        -> fixity InfixN 4
+  "+="        -> fixity InfixN 4
+  "-="        -> fixity InfixN 4
+  "*="        -> fixity InfixN 4
+  "//="       -> fixity InfixN 4
+  "^="        -> fixity InfixN 4
+  "^^="       -> fixity InfixN 4
+  "**="       -> fixity InfixN 4
+  "&&="       -> fixity InfixN 4
+  "||="       -> fixity InfixN 4
+  "<~"        -> fixity InfixR 2
+  "<.="       -> fixity InfixN 4
+  "<?="       -> fixity InfixN 4
+  "<>~"       -> fixity InfixR 4
+  "<>="       -> fixity InfixN 4
+  "^.."       -> fixity InfixL 8
+  "^?"        -> fixity InfixL 8
+  "^?!"       -> fixity InfixL 8
+  "^@.."      -> fixity InfixL 8
+  "^@?"       -> fixity InfixL 8
+  "^@?!"      -> fixity InfixL 8
+  "^."        -> fixity InfixL 8
+  "^@."       -> fixity InfixL 8
+  "<."        -> fixity InfixR 9
+  ".>"        -> fixity InfixR 9
+  "<.>"       -> fixity InfixR 9
+  "@@~"       -> fixity InfixR 4
+  "@@="       -> fixity InfixR 4
+  "&~"        -> fixity InfixL 1
+  "??"        -> fixity InfixL 1
+
+
+  -- certain other operators
+  -- "%."        -> Just $ Fixity NoSourceText _ _
+  -- "%=="       -> Just $ Fixity NoSourceText _ _
+  -- "%=>%"      -> Just $ Fixity NoSourceText _ _
+  -- "&*"        -> Just $ Fixity NoSourceText _ _
+  -- "&/"        -> Just $ Fixity NoSourceText _ _
+  -- "&="        -> Just $ Fixity NoSourceText _ _
+  -- "-->"       -> Just $ Fixity NoSourceText _ _
+  -- ".*?"       -> fixity _ _
+  -- ".+."       -> fixity _ _
+  -- ".-."       -> fixity _ _
+  ".&."       -> fixity InfixR 1
+  ".&&."      -> fixity InfixR 1
+  ".||."      -> fixity InfixR 1
+  "==>"       -> fixity InfixR 0
+  "=/="       -> fixity InfixN 4
+  "==="       -> fixity InfixN 4
+  ".:!"       -> fixity InfixL 9
+  ".:?"       -> fixity InfixL 9
+  -- ".:>"       -> fixity _ _
+  -- ".:>?"      -> fixity _ _
+  "<.>"       -> fixity InfixR 7
+  "</>"       -> fixity InfixR 5
+  "<?>"       -> fixity InfixL 9
+  -- "~"         -> fixity _ _
+  "==="       -> fixity InfixN 4
+  "!?"        -> fixity InfixL 9
+  "%=="       -> fixity InfixN 3
+  ".*"        -> fixity InfixR 8
+  ".**"       -> fixity InfixR 8
+  ".***"      -> fixity InfixR 8
+  ":?-"       -> fixity InfixN 1
+  "::-"       -> fixity InfixN 0
+  "&!"        -> fixity InfixL 1
+  
+  -- quickcheck (-state-machine)
+  ":&&"       -> fixity InfixL 9
+  ":||"       -> fixity InfixL 9
+  ":&&:"      -> fixity InfixL 9
+  ":=>"       -> fixity InfixL 9
+  ":=="       -> fixity InfixL 9
+  ":/="       -> fixity InfixL 9
+  ":<"        -> fixity InfixL 9
+  ":<="       -> fixity InfixL 9
+  ":>"        -> fixity InfixL 9
+  ":>="       -> fixity InfixL 9
+  ":->"       -> fixity InfixL 9
+
+  -- servant
+  ":>"        -> fixity InfixR 4
+  ":<|>"      -> fixity InfixR 3
+  ":-"        -> fixity InfixL 0
+
+  -- postgresql-simple
+  ":."        -> fixity InfixR 3 -- this has wildly different fixities in different libraries
+
+  -- ?
+  -- ":-:"       -> fixity _ _
+  -- ":."        -> fixity _ _
+  -- ":/:"       -> fixity _ _
+  -- "::->"      -> fixity _ _
+  -- ":<:"       -> fixity _ _
+  -- ":<=:"      -> fixity _ _
+  -- ":=:"       -> fixity _ _
+  -- ":>:"       -> fixity _ _
+  -- ":>=:"      -> fixity _ _
 
   str         -> case (Safe.headMay str, Safe.lastMay str) of
     (Just '\'', _) -> hardcodedFixity False (drop 1 str)
@@ -277,3 +405,4 @@ hardcodedFixity allowUnqualify = \case
     (Just c, _) | Data.Char.isAlpha c && allowUnqualify -> hardcodedFixity False
       $ dropWhile (\x -> (Data.Char.isAlpha x || x == '.')) str
     _ -> Nothing
+  where fixity a b = Just (Fixity NoSourceText b a)