Perf: Do not split source into lines at every fix

src/Lint/Fix.elm

@@ -77,7 +77,8 @@ fix : List Fix -> String -> String
 fix fixes sourceCode =
     fixes
         |> List.sortBy (rangePosition >> negate)
-        |> List.foldl applyFix sourceCode
+        |> List.foldl applyFix (String.lines sourceCode)
+        |> String.join "\n"
 
 
 rangePosition : Fix -> Int
@@ -101,6 +102,86 @@ rangePosition fix_ =
     row * 1000000 + column
 
 
+comparePosition : { row : Int, column : Int } -> { row : Int, column : Int } -> Order
+comparePosition a b =
+    let
+        order : Order
+        order =
+            compare a.row b.row
+    in
+    case order of
+        EQ ->
+            compare a.column b.column
+
+        _ ->
+            order
+
+
+applyFix : Fix -> List String -> List String
+applyFix fix_ lines =
+    lines
+        |> (case fix_ of
+                Replacement range replacement ->
+                    applyReplace range replacement
+
+                Removal range ->
+                    applyReplace range ""
+
+                InsertAt position insertion ->
+                    applyReplace { start = position, end = position } insertion
+           )
+
+
+applyReplace : Range -> String -> List String -> List String
+applyReplace range replacement lines =
+    let
+        linesBefore : List String
+        linesBefore =
+            lines
+                |> List.take (range.start.row - 1)
+
+        linesAfter : List String
+        linesAfter =
+            lines
+                |> List.drop range.end.row
+
+        startLine : String
+        startLine =
+            getRowAtLine lines (range.start.row - 1)
+
+        startLineBefore : String
+        startLineBefore =
+            String.slice 0 (range.start.column - 1) startLine
+
+        endLine : String
+        endLine =
+            getRowAtLine lines (range.end.row - 1)
+
+        endLineAfter : String
+        endLineAfter =
+            String.dropLeft (range.end.column - 1) endLine
+    in
+    List.concat
+        [ linesBefore
+        , startLineBefore ++ replacement ++ endLineAfter |> String.lines
+        , linesAfter
+        ]
+
+
+getRowAtLine : List String -> Int -> String
+getRowAtLine lines rowIndex =
+    case lines |> Array.fromList |> Array.get rowIndex of
+        Just line ->
+            if String.trim line /= "" then
+                line
+
+            else
+                ""
+
+        Nothing ->
+            ""
+
+
 
 -- UTILITARIES FOR WORKING WITH RANGES
 
@@ -144,134 +225,3 @@ mergeRanges a b =
                     a.end
     in
     { start = start, end = end }
-
-
-comparePosition : { row : Int, column : Int } -> { row : Int, column : Int } -> Order
-comparePosition a b =
-    let
-        order : Order
-        order =
-            compare a.row b.row
-    in
-    case order of
-        EQ ->
-            compare a.column b.column
-
-        _ ->
-            order
-
-
-applyFix : Fix -> String -> String
-applyFix fix_ source =
-    source
-        |> (case fix_ of
-                Replacement range replacement ->
-                    applyReplace range replacement
-
-                Removal range ->
-                    applyReplace range ""
-
-                InsertAt position insertion ->
-                    applyReplace { start = position, end = position } insertion
-           )
-
-
-applyReplace : Range -> String -> String -> String
-applyReplace range replacement source =
-    if range.start.row == range.end.row then
-        applySingleLineReplace
-            range
-            replacement
-            source
-
-    else
-        applyMultiLineReplace
-            range
-            replacement
-            source
-
-
-applySingleLineReplace : Range -> String -> String -> String
-applySingleLineReplace range replacement source =
-    let
-        lines : List String
-        lines =
-            String.lines source
-
-        linesBefore : String
-        linesBefore =
-            lines
-                |> List.take (range.start.row - 1)
-                |> String.join "\n"
-
-        linesAfter : String
-        linesAfter =
-            lines
-                |> List.drop range.end.row
-                |> String.join "\n"
-
-        line : String
-        line =
-            getRowAtLine lines (range.start.row - 1)
-
-        lineBefore : String
-        lineBefore =
-            String.slice 0 (range.start.column - 1) line
-
-        lineAfter : String
-        lineAfter =
-            String.dropLeft (range.end.column - 1) line
-    in
-    linesBefore ++ "\n" ++ lineBefore ++ replacement ++ lineAfter ++ "\n" ++ linesAfter
-
-
-applyMultiLineReplace : Range -> String -> String -> String
-applyMultiLineReplace range replacement source =
-    let
-        lines : List String
-        lines =
-            String.lines source
-
-        linesBefore : String
-        linesBefore =
-            lines
-                |> List.take (range.start.row - 1)
-                |> String.join "\n"
-
-        linesAfter : String
-        linesAfter =
-            lines
-                |> List.drop range.end.row
-                |> String.join "\n"
-
-        startLine : String
-        startLine =
-            getRowAtLine lines (range.start.row - 1)
-
-        startLineBefore : String
-        startLineBefore =
-            String.slice 0 (range.start.column - 1) startLine
-
-        endLine : String
-        endLine =
-            getRowAtLine lines (range.end.row - 1)
-
-        endLineAfter : String
-        endLineAfter =
-            String.dropLeft (range.end.column - 1) endLine
-    in
-    linesBefore ++ "\n" ++ startLineBefore ++ replacement ++ endLineAfter ++ "\n" ++ linesAfter
-
-
-getRowAtLine : List String -> Int -> String
-getRowAtLine lines rowIndex =
-    case lines |> Array.fromList |> Array.get rowIndex of
-        Just line ->
-            if String.trim line /= "" then
-                line
-
-            else
-                ""
-
-        Nothing ->
-            ""