Fix some hlint warnings

programs/AttrDemo.hs

@@ -30,9 +30,9 @@ ui =
     vBox [ str "This text uses the global default attribute."
          , withAttr (attrName "foundFull") $
            str "Specifying an attribute name means we look it up in the attribute tree."
-         , (withAttr (attrName "foundFgOnly") $
-           str ("When we find a value, we merge it with its parent in the attribute")
-           <=> str "name tree all the way to the root (the global default).")
+         , withAttr (attrName "foundFgOnly") $
+           str "When we find a value, we merge it with its parent in the attribute"
+           <=> str "name tree all the way to the root (the global default)."
          , withAttr (attrName "missing") $
            str "A missing attribute name just resumes the search at its parent."
          , withAttr (attrName "general" <> attrName "specific") $
@@ -42,7 +42,7 @@ ui =
          , withAttr (attrName "foundFgOnly") $
            str "... or only what you want to change and inherit the rest."
          , str "Attribute names are assembled with the Monoid append operation to indicate"
-         , str "hierarchy levels, e.g. \"window\" <> \"title\"."
+         , str "hierarchy levels, e.g. attrName \"window\" <> attrName \"title\"."
          , str " "
          , withAttr (attrName "linked") $
            str "This text is hyperlinked in terminals that support hyperlinking."

programs/CroppingDemo.hs

@@ -27,7 +27,7 @@ import qualified Graphics.Vty as V
 
 example :: Widget n
 example =
-    border $
+    border
     (txt "Example" <=> txt "Widget")
 
 mkExample :: Widget n -> Widget n

programs/LayerDemo.hs

@@ -12,13 +12,10 @@ import Control.Monad (void)
 import qualified Graphics.Vty as V
 
 import qualified Brick.Types as T
-import Brick.Types (locationRowL, locationColumnL, Widget)
+import Brick.Types (locationRowL, locationColumnL, Location(..), Widget)
 import qualified Brick.Main as M
 import qualified Brick.Widgets.Border as B
 import qualified Brick.Widgets.Center as C
-import Brick.Types
-  ( Location(..)
-  )
 import Brick.Widgets.Core
   ( translateBy
   , str

programs/ViewportScrollbarsDemo.hs

@@ -130,7 +130,7 @@ appEvent _ = return ()
 
 theme :: AttrMap
 theme =
-    attrMap V.defAttr $
+    attrMap V.defAttr
     [ (scrollbarAttr,       fg V.white)
     , (scrollbarHandleAttr, fg V.brightYellow)
     ]

src/Brick/AttrMap.hs

@@ -47,7 +47,7 @@ import qualified Data.Semigroup as Sem
 import Control.DeepSeq
 import Data.Bits ((.|.))
 import qualified Data.Map as M
-import Data.Maybe (catMaybes)
+import Data.Maybe (mapMaybe)
 import Data.List (inits)
 import GHC.Generics (Generic)
 
@@ -150,7 +150,7 @@ attrMapLookup :: AttrName -> AttrMap -> Attr
 attrMapLookup _ (ForceAttr a) = a
 attrMapLookup (AttrName []) (AttrMap theDefault _) = theDefault
 attrMapLookup (AttrName ns) (AttrMap theDefault m) =
-    let results = catMaybes $ (\n -> M.lookup n m) <$> (AttrName <$> (inits ns))
+    let results = mapMaybe (\n -> M.lookup (AttrName n) m) (inits ns)
     in foldl combineAttrs theDefault results
 
 -- | Set the default attribute value in an attribute map.

src/Brick/BorderMap.hs

@@ -1,6 +1,5 @@
 {-# LANGUAGE DeriveFunctor #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
-{-# LANGUAGE TemplateHaskell #-}
 {-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE DeriveAnyClass #-}
 module Brick.BorderMap

src/Brick/Forms.hs

@@ -281,7 +281,7 @@ newForm :: [s -> FormFieldState s e n]
 newForm mkEs s =
     let es = mkEs <*> pure s
     in Form { formFieldStates = es
-            , formFocus       = focusRing $ concat $ formFieldNames <$> es
+            , formFocus       = focusRing $ concatMap formFieldNames es
             , formState       = s
             , formConcatAll   = vBox
             }
@@ -482,7 +482,7 @@ renderRadio lb check rb val name label foc cur =
         csr = if foc then putCursor name (Location (1,0)) else id
     in clickable name $
        addAttr $ csr $
-       txt $ T.concat $
+       txt $ T.concat
        [ T.singleton lb
        , if isSet then T.singleton check else " "
        , T.singleton rb <> " " <> label
@@ -664,7 +664,7 @@ allFieldsValid = null . invalidFields
 -- force the user to repair invalid inputs before moving on from a form
 -- editing session.
 invalidFields :: Form s e n -> [n]
-invalidFields f = concat $ getInvalidFields <$> formFieldStates f
+invalidFields f = concatMap getInvalidFields (formFieldStates f)
 
 -- | Manually indicate that a field has invalid contents. This can be
 -- useful in situations where validation beyond the form element's
@@ -695,8 +695,8 @@ setFieldValid v n form =
 getInvalidFields :: FormFieldState s e n -> [n]
 getInvalidFields (FormFieldState st _ _ fs _ _) =
     let gather (FormField n validate extValid _ _) =
-            if (not extValid || (isNothing $ validate st)) then [n] else []
-    in concat $ gather <$> fs
+            if not extValid || isNothing (validate st) then [n] else []
+    in concatMap gather fs
 
 -- | Render a form.
 --

src/Brick/Keybindings/KeyDispatcher.hs

@@ -172,7 +172,7 @@ buildKeyDispatcherPairs ks conf = pairs
     where
         pairs = mkPair <$> handlers
         mkPair h = (khBinding h, h)
-        handlers = concat $ keyHandlersFromConfig conf <$> ks
+        handlers = concatMap (keyHandlersFromConfig conf) ks
 
 keyHandlersFromConfig :: (Ord k)
                       => KeyConfig k

src/Brick/Types.hs

@@ -1,5 +1,4 @@
 -- | Basic types used by this library.
-{-# LANGUAGE TemplateHaskell #-}
 {-# LANGUAGE RankNTypes #-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 module Brick.Types

src/Brick/Widgets/Border/Style.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE DeriveAnyClass #-}
 -- | This module provides styles for borders as used in terminal

src/Brick/Widgets/Core.hs

@@ -691,9 +691,9 @@ renderBox br ws =
           paddedImages = padImage <$> rewrittenImages
 
       cropResultToContext $ Result (concatenatePrimary br paddedImages)
-                            (concat $ cursors <$> allTranslatedResults)
-                            (concat $ visibilityRequests <$> allTranslatedResults)
-                            (concat $ extents <$> allTranslatedResults)
+                            (concatMap cursors allTranslatedResults)
+                            (concatMap visibilityRequests allTranslatedResults)
+                            (concatMap extents allTranslatedResults)
                             newBorders
 
 catDynBorder
@@ -1430,10 +1430,10 @@ viewport vpname typ p =
 
       -- If the rendering state includes any scrolling requests for this
       -- viewport, apply those
-      reqs <- lift $ gets $ (^.rsScrollRequestsL)
+      reqs <- lift $ gets (^.rsScrollRequestsL)
       let relevantRequests = snd <$> filter (\(n, _) -> n == vpname) reqs
       when (not $ null relevantRequests) $ do
-          mVp <- lift $ gets $ (^.viewportMapL.to (M.lookup vpname))
+          mVp <- lift $ gets (^.viewportMapL.to (M.lookup vpname))
           case mVp of
               Nothing -> error $ "BUG: viewport: viewport name " <> show vpname <> " absent from viewport map"
               Just vp -> do
@@ -1451,7 +1451,7 @@ viewport vpname typ p =
       -- If the sub-rendering requested visibility, update the scroll
       -- state accordingly
       when (not $ null $ initialResult^.visibilityRequestsL) $ do
-          mVp <- lift $ gets $ (^.viewportMapL.to (M.lookup vpname))
+          mVp <- lift $ gets (^.viewportMapL.to (M.lookup vpname))
           case mVp of
               Nothing -> error $ "BUG: viewport: viewport name " <> show vpname <> " absent from viewport map"
               Just vp -> do
@@ -1464,7 +1464,7 @@ viewport vpname typ p =
 
       -- If the size of the rendering changes enough to make the
       -- viewport offsets invalid, reset them
-      mVp <- lift $ gets $ (^.viewportMapL.to (M.lookup vpname))
+      mVp <- lift $ gets (^.viewportMapL.to (M.lookup vpname))
       vp <- case mVp of
           Nothing -> error $ "BUG: viewport: viewport name " <> show vpname <> " absent from viewport map"
           Just v -> return v

src/Brick/Widgets/Internal.hs

@@ -12,10 +12,9 @@ import Lens.Micro ((^.), (&), (%~))
 import Lens.Micro.Mtl ((%=))
 import Control.Monad.State.Strict
 import Control.Monad.Reader
-import Data.Maybe (fromMaybe)
+import Data.Maybe (fromMaybe, mapMaybe)
 import qualified Data.Map as M
 import qualified Data.Set as S
-import Data.Maybe (catMaybes)
 import qualified Graphics.Vty as V
 
 import Brick.Types
@@ -63,7 +62,7 @@ renderFinal aMap layerRenders (w, h) chooseCursor rs =
                       }
 
         layersTopmostFirst = reverse layerResults
-        pic = V.picForLayers $ uncurry V.resize (w, h) <$> (^.imageL) <$> layersTopmostFirst
+        pic = V.picForLayers $ V.resize w h <$> (^.imageL) <$> layersTopmostFirst
 
         -- picWithBg is a workaround for runaway attributes.
         -- See https://github.com/coreyoconnor/vty/issues/95
@@ -91,7 +90,7 @@ cropImage :: Context n -> V.Image -> V.Image
 cropImage c = V.crop (max 0 $ c^.availWidthL) (max 0 $ c^.availHeightL)
 
 cropCursors :: Context n -> [CursorLocation n] -> [CursorLocation n]
-cropCursors ctx cs = catMaybes $ cropCursor <$> cs
+cropCursors ctx cs = mapMaybe cropCursor cs
     where
         -- A cursor location is removed if it is not within the region
         -- described by the context.
@@ -105,7 +104,7 @@ cropCursors ctx cs = catMaybes $ cropCursor <$> cs
                ]
 
 cropExtents :: Context n -> [Extent n] -> [Extent n]
-cropExtents ctx es = catMaybes $ cropExtent <$> es
+cropExtents ctx es = mapMaybe cropExtent es
     where
         -- An extent is cropped in places where it is not within the
         -- region described by the context.

src/Brick/Widgets/List.hs

@@ -1,8 +1,6 @@
 {-# LANGUAGE TupleSections #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE TemplateHaskell #-}
-{-# LANGUAGE DeriveFunctor #-}
-{-# LANGUAGE DeriveFoldable#-}
 {-# LANGUAGE DeriveTraversable #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE FlexibleInstances #-}

tests/List.hs

@@ -4,7 +4,6 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TemplateHaskell #-}
-{-# LANGUAGE TypeSynonymInstances #-}
 module List
   ( main
   )

tests/Main.hs

@@ -112,5 +112,5 @@ return []
 
 main :: IO ()
 main =
-  (all id <$> sequenceA [$quickCheckAll, List.main, Render.main])
+  (and <$> sequenceA [$quickCheckAll, List.main, Render.main])
   >>= bool exitFailure exitSuccess

tests/Render.hs

@@ -1,5 +1,4 @@
 {-# LANGUAGE CPP #-}
-{-# LANGUAGE TypeApplications #-}
 module Render
   ( main
   )