Minor changes

Author: MonoidMusician

src/DOM/Util/TextCursor.purs

@@ -6,9 +6,8 @@ module DOM.Util.TextCursor
     , isCursor, cursorAtStart, cursorAtEnd
     , isSelection, selectionAtStart, selectionAtEnd
     , selectAll, moveCursorToStart, moveCursorToEnd
-    , appendLeft, appendRight
     , modifySelected, modifyAll
-    , insert
+    , appendl, appendr, insert
     ) where
 
 import Prelude
@@ -114,12 +113,8 @@ _after = _Newtype <<< prop (SProxy :: SProxy "after")
 
 -- | Lens for traversing/setting all three fields.
 _all :: Traversal' TextCursor String
-_all = wander trav
-    where
-        -- Monomorphic traverse
-        trav :: forall m. Applicative m => (String -> m String) -> TextCursor -> m TextCursor
-        trav f (TextCursor { before, selected, after }) =
-            mkTextCursor <$> f before <*> f selected <*> f after
+_all = wander \f (TextCursor { before, selected, after }) ->
+    mkTextCursor <$> f before <*> f selected <*> f after
 
 -- | Test whether the cursor or selection touches the start.
 atStart :: TextCursor -> Boolean
@@ -187,14 +182,6 @@ moveCursorToEnd tc = TextCursor
     , after: ""
     }
 
--- | Prepend a string, on the left.
-appendLeft :: String -> TextCursor -> TextCursor
-appendLeft s tc = over _before (s <> _) tc
-
--- | Append a string, on the right.
-appendRight :: TextCursor -> String -> TextCursor
-appendRight tc s = over _after (_ <> s) tc
-
 -- | Modify just the selected region with an endomorphism.
 modifySelected :: (String -> String) -> TextCursor -> TextCursor
 modifySelected = over _selected
@@ -204,8 +191,17 @@ modifySelected = over _selected
 modifyAll :: (String -> String) -> TextCursor -> TextCursor
 modifyAll = over _all
 
+-- | Prepend a string, on the left.
+appendl :: String -> TextCursor -> TextCursor
+appendl s tc = over _before (s <> _) tc
+
+-- | Append a string, on the right.
+appendr :: TextCursor -> String -> TextCursor
+appendr tc s = over _after (_ <> s) tc
+
 -- | Insert a string at the cursor position. If text is selected, the insertion
 -- | will be part of the selection. Otherwise it is inserted before the cursor.
+-- Preserves normalization
 -- check:
 --     length (insert insertion textcursor)
 --  == length insertion + length textcursor

src/DOM/Util/TextCursor/Element.purs

@@ -8,7 +8,6 @@ module DOM.Util.TextCursor.Element
 
 import Prelude
 import Data.Maybe (Maybe(Just))
-import Data.Tuple (Tuple(Tuple))
 import Data.String (length, splitAt)
 import Data.Lens (Lens', (.~))
 import Control.Monad.Eff (Eff)
@@ -34,20 +33,20 @@ import DOM.Util.TextCursor.Element.HTML
 
 -- | Helper to split a `String` at a specific position without worrying about
 -- | `Nothing`.
-splitAtTuple :: Int -> String -> Tuple String String
-splitAtTuple i s = case splitAt i s of
-    Just {before, after} -> Tuple before after
-    _ | i > 0     -> Tuple s ""
-      | otherwise -> Tuple "" s
+splitAtRec :: Int -> String -> { before :: String, after :: String }
+splitAtRec i s = case splitAt i s of
+    Just split    -> split
+    _ | i > 0     -> { before: s, after: "" }
+      | otherwise -> { before: "", after: s }
 
 -- | Get the `TextCursor` from a `TextCursorElement`.
 textCursor :: forall eff. TextCursorElement -> Eff ( dom :: DOM | eff ) TextCursor
 textCursor element = do
     val <- value element
     start <- selectionStart element
     end <- selectionEnd element
-    let (Tuple prior after) = splitAtTuple end val
-    let (Tuple before selected) = splitAtTuple start prior
+    let { before: prior, after } = splitAtRec end val
+    let { before, after: selected } = splitAtRec start prior
     pure $ TextCursor
         { before
         , selected

src/DOM/Util/TextCursor/Monoid.purs

@@ -3,7 +3,7 @@ module DOM.Util.TextCursor.Monoid where
 import Prelude
 import DOM.Util.TextCursor
     ( TextCursor, empty
-    , appendLeft, appendRight
+    , appendl, appendr
     , isCursor, content
     )
 import Data.Monoid (class Monoid)
@@ -20,10 +20,10 @@ instance rightmostMonoid :: Monoid Rightmost where mempty = Rightmost empty
 
 instance leftmostSemigroup :: Semigroup Leftmost where
     append (Leftmost l) (Leftmost r)
-        | isCursor l = Leftmost (content l `appendLeft` r)
-        | otherwise  = Leftmost (l `appendRight` content r)
+        | isCursor l = Leftmost (content l `appendl` r)
+        | otherwise  = Leftmost (l `appendr` content r)
 
 instance rightmostSemigroup :: Semigroup Rightmost where
     append (Rightmost l) (Rightmost r)
-        | isCursor r = Rightmost (l `appendRight` content r)
-        | otherwise  = Rightmost (content l `appendLeft` r)
+        | isCursor r = Rightmost (l `appendr` content r)
+        | otherwise  = Rightmost (content l `appendl` r)