🔥 Use just isFoldableAtBufferRow

src/display-buffer.coffee

@@ -413,8 +413,8 @@ class DisplayBuffer extends Model
   isFoldedAtScreenRow: (screenRow) ->
     @largestFoldContainingBufferRow(@bufferRowForScreenRow(screenRow))?
 
-  foldableBufferRowsForBufferRowRange: (startRow, endRow) ->
-    @tokenizedBuffer.foldableRowsForRowRange(startRow, endRow)
+  isFoldableAtBufferRow: (row) ->
+    @tokenizedBuffer.isFoldableAtRow(row)
 
   # Destroys the fold with the given id
   destroyFoldWithId: (id) ->

src/text-editor-presenter.coffee

@@ -600,8 +600,14 @@ class TextEditorPresenter
 
     if endRow > startRow
       bufferRows = @model.bufferRowsForScreenRows(startRow, endRow - 1)
-      foldableBufferRows = @model.foldableBufferRowsForBufferRowRange(bufferRows[0], bufferRows[bufferRows.length - 1])
+      previousBufferRow = -1
+      foldable = false
       for bufferRow, i in bufferRows
+         # don't compute foldability more than once per buffer row
+        if previousBufferRow isnt bufferRow
+          foldable = @model.isFoldableAtBufferRow(bufferRow)
+          previousBufferRow = bufferRow
+
         if bufferRow is lastBufferRow
           softWrapped = true
         else
@@ -611,7 +617,6 @@ class TextEditorPresenter
         screenRow = startRow + i
         line = @model.tokenizedLineForScreenRow(screenRow)
         decorationClasses = @lineNumberDecorationClassesForRow(screenRow)
-        foldable = foldableBufferRows.has(bufferRow)
         blockDecorationsBeforeCurrentScreenRowHeight = @lineTopIndex.pixelPositionAfterBlocksForRow(screenRow) - @lineTopIndex.pixelPositionBeforeBlocksForRow(screenRow)
         blockDecorationsHeight = blockDecorationsBeforeCurrentScreenRowHeight
         if screenRow % @tileSize isnt 0

src/text-editor.coffee

@@ -2939,8 +2939,7 @@ class TextEditor extends Model
   #
   # Returns a {Boolean}.
   isFoldableAtBufferRow: (bufferRow) ->
-    # @languageMode.isFoldableAtBufferRow(bufferRow)
-    @foldableBufferRowsForBufferRowRange(bufferRow, bufferRow).has(bufferRow)
+    @displayBuffer.isFoldableAtBufferRow(bufferRow)
 
   # Extended: Determine whether the given row in screen coordinates is foldable.
   #
@@ -2953,9 +2952,6 @@ class TextEditor extends Model
     bufferRow = @displayBuffer.bufferRowForScreenRow(screenRow)
     @isFoldableAtBufferRow(bufferRow)
 
-  foldableBufferRowsForBufferRowRange: (startRow, endRow) ->
-    @displayBuffer.foldableBufferRowsForBufferRowRange(startRow, endRow)
-
   # Extended: Fold the given buffer row if it isn't currently folded, and unfold
   # it otherwise.
   toggleFoldAtBufferRow: (bufferRow) ->

src/tokenized-buffer.coffee

@@ -282,15 +282,6 @@ class TokenizedBuffer extends Model
 
     row - increment
 
-  foldableRowsForRowRange: (startRow, endRow) ->
-    scanStartRow = @buffer.previousNonBlankRow(startRow) ? startRow
-    scanStartRow-- while scanStartRow > 0 and @tokenizedLineForRow(scanStartRow).isComment()
-    scanEndRow = @buffer.nextNonBlankRow(endRow) ? endRow
-    foldableRows = new Set
-    for row in [scanStartRow..scanEndRow] by 1 when @isFoldableAtRow(row)
-      foldableRows.add(row)
-    foldableRows
-
   isFoldableAtRow: (row) ->
     if @largeFileMode
       false

src/tokenized-line.coffee

@@ -33,7 +33,6 @@ class TokenizedLine
   endOfLineInvisibles: null
   lineIsWhitespaceOnly: false
   firstNonWhitespaceIndex: 0
-  foldable: false
 
   constructor: (properties) ->
     @id = idCounter++