Add backwardsScan function

spec/text-buffer-spec.coffee

@@ -992,7 +992,7 @@ describe "TextBuffer", ->
       runs ->
         expect(buffer.isModified()).toBeFalsy()
 
-  describe ".getLines()", ->
+  describe "::getLines()", ->
     it "returns an array of lines in the text contents", ->
       filePath = require.resolve('./fixtures/sample.js')
       fileContents = readFileSync(filePath, 'utf8')
@@ -1005,7 +1005,7 @@ describe "TextBuffer", ->
         expect(buffer.getLines().length).toBe fileContents.split("\n").length
         expect(buffer.getLines().join('\n')).toBe fileContents
 
-  describe ".change(range, string)", ->
+  describe "::change(range, string)", ->
     changeHandler = null
 
     beforeEach ->
@@ -1122,7 +1122,7 @@ describe "TextBuffer", ->
       buffer.change([0, 0], "hello")
       expect(buffer.lineForRow(0)).toBe "var quicksort = function () {"
 
-  describe ".setText(text)", ->
+  describe "::setText(text)", ->
     beforeEach ->
       filePath = require.resolve('./fixtures/sample.js')
       buffer = new TextBuffer({filePath, load: true})
@@ -1147,7 +1147,7 @@ describe "TextBuffer", ->
       expect(event.oldRange).toEqual expectedPreRange
       expect(event.newRange).toEqual [[0, 0], [1, 14]]
 
-  describe ".setTextViaDiff(text)", ->
+  describe "::setTextViaDiff(text)", ->
     beforeEach ->
       filePath = require.resolve('./fixtures/sample.js')
       buffer = new TextBuffer({filePath, load: true})
@@ -1216,7 +1216,7 @@ describe "TextBuffer", ->
         buffer.setTextViaDiff(newText)
         expect(buffer.getText()).toBe newText
 
-  describe ".save()", ->
+  describe "::save()", ->
     saveBuffer = null
 
     afterEach ->
@@ -1311,7 +1311,7 @@ describe "TextBuffer", ->
         expect(buffer.isInConflict()).toBeFalsy()
         expect(buffer.getText()).toBe(fileContents)
 
-  describe ".saveAs(path)", ->
+  describe "::saveAs(path)", ->
     [filePath, saveAsBuffer] = []
 
     afterEach ->
@@ -1359,7 +1359,7 @@ describe "TextBuffer", ->
       waitsFor ->
         changeHandler.callCount > 0
 
-  describe ".getTextInRange(range)", ->
+  describe "::getTextInRange(range)", ->
     beforeEach ->
       filePath = require.resolve('./fixtures/sample.js')
       buffer = new TextBuffer({filePath, load: true})
@@ -1399,25 +1399,47 @@ describe "TextBuffer", ->
       it "clips the range to the end of the buffer", ->
         expect(buffer.getTextInRange([[12], [13, Infinity]])).toBe buffer.lineForRow(12)
 
-  describe ".scan(regex, fn)", ->
+  describe "::scan(regex, fn)", ->
     beforeEach ->
-      filePath = require.resolve('./fixtures/sample.js')
-      buffer = new TextBuffer({filePath, load: true})
+      buffer = new TextBuffer(filePath: require.resolve('./fixtures/sample.js'))
+      buffer.loadSync()
 
-      waitsFor ->
-        buffer.loaded
+    it "calls the given function with the information about each match", ->
+      matches = []
+      buffer.scan /current/g, (match) -> matches.push(match)
+      expect(matches.length).toBe 5
 
-    it "retunrns lineText and lineTextOffset", ->
+      expect(matches[0].matchText).toBe 'current'
+      expect(matches[0].range).toEqual [[3, 31], [3, 38]]
+      expect(matches[0].lineText).toBe '    var pivot = items.shift(), current, left = [], right = [];'
+      expect(matches[0].lineTextOffset).toBe 0
+
+      expect(matches[1].matchText).toBe 'current'
+      expect(matches[1].range).toEqual [[5, 6], [5, 13]]
+      expect(matches[1].lineText).toBe '      current = items.shift();'
+      expect(matches[1].lineTextOffset).toBe 0
+
+  describe "::backwardsScan(regex, fn)", ->
+    beforeEach ->
+      buffer = new TextBuffer(filePath: require.resolve('./fixtures/sample.js'))
+      buffer.loadSync()
+
+    it "calls the given function with the information about each match in backwards order", ->
       matches = []
-      buffer.scan /current/, (match) ->
-        matches.push(match)
-      expect(matches.length).toBe 1
+      buffer.backwardsScan /current/g, (match) -> matches.push(match)
+      expect(matches.length).toBe 5
 
-      expect(matches[0].matchText).toEqual 'current'
-      expect(matches[0].lineText).toEqual '    var pivot = items.shift(), current, left = [], right = [];'
+      expect(matches[0].matchText).toBe 'current'
+      expect(matches[0].range).toEqual [[6, 56], [6, 63]]
+      expect(matches[0].lineText).toBe '      current < pivot ? left.push(current) : right.push(current);'
       expect(matches[0].lineTextOffset).toBe 0
 
-  describe ".scanInRange(range, regex, fn)", ->
+      expect(matches[1].matchText).toBe 'current'
+      expect(matches[1].range).toEqual [[6, 34], [6, 41]]
+      expect(matches[1].lineText).toBe '      current < pivot ? left.push(current) : right.push(current);'
+      expect(matches[1].lineTextOffset).toBe 0
+
+  describe "::scanInRange(range, regex, fn)", ->
     beforeEach ->
       filePath = require.resolve('./fixtures/sample.js')
       buffer = new TextBuffer({filePath, load: true})
@@ -1535,7 +1557,7 @@ describe "TextBuffer", ->
 
         expect(ranges.length).toBe 2
 
-  describe ".backwardsScanInRange(range, regex, fn)", ->
+  describe "::backwardsScanInRange(range, regex, fn)", ->
     beforeEach ->
       filePath = require.resolve('./fixtures/sample.js')
       buffer = new TextBuffer({filePath, load: true})
@@ -1606,7 +1628,7 @@ describe "TextBuffer", ->
         expect(ranges[0]).toEqual [[6,34], [6,41]]
         expect(ranges[1]).toEqual [[6,6], [6,13]]
 
-  describe ".characterIndexForPosition(position)", ->
+  describe "::characterIndexForPosition(position)", ->
     beforeEach ->
       filePath = require.resolve('./fixtures/sample.js')
       buffer = new TextBuffer({filePath, load: true})
@@ -1630,7 +1652,7 @@ describe "TextBuffer", ->
         expect(buffer.characterIndexForPosition([2])).toBe 13
         expect(buffer.characterIndexForPosition([3])).toBe 20
 
-  describe ".positionForCharacterIndex(position)", ->
+  describe "::positionForCharacterIndex(position)", ->
     beforeEach ->
       filePath = require.resolve('./fixtures/sample.js')
       buffer = new TextBuffer({filePath, load: true})
@@ -1653,7 +1675,7 @@ describe "TextBuffer", ->
         expect(buffer.positionForCharacterIndex(13)).toEqual [2, 0]
         expect(buffer.positionForCharacterIndex(20)).toEqual [3, 0]
 
-  describe ".usesSoftTabs()", ->
+  describe "::usesSoftTabs()", ->
     beforeEach ->
       filePath = require.resolve('./fixtures/sample.js')
       buffer = new TextBuffer({filePath, load: true})
@@ -1669,7 +1691,7 @@ describe "TextBuffer", ->
       buffer.setText("")
       expect(buffer.usesSoftTabs()).toBeUndefined()
 
-  describe ".isEmpty()", ->
+  describe "::isEmpty()", ->
     beforeEach ->
       filePath = require.resolve('./fixtures/sample.js')
       buffer = new TextBuffer({filePath, load: true})
@@ -1730,7 +1752,7 @@ describe "TextBuffer", ->
       runs ->
         expect(contentsModifiedHandler).toHaveBeenCalledWith(false)
 
-  describe ".append(text)", ->
+  describe "::append(text)", ->
     beforeEach ->
       filePath = require.resolve('./fixtures/sample.js')
       buffer = new TextBuffer({filePath, load: true})

src/text-buffer.coffee

@@ -654,6 +654,16 @@ class TextBuffer
       result.lineTextOffset = 0
       iterator(result)
 
+  # Scans for text in the buffer _backwards_, calling a function on each match.
+  #
+  # regex - A {RegExp} representing the text to find.
+  # iterator - A {Function} that's called on each match.
+  backwardsScan: (regex, iterator) ->
+    @backwardsScanInRange regex, @getRange(), (result) =>
+      result.lineText = @lineForRow(result.range.start.row)
+      result.lineTextOffset = 0
+      iterator(result)
+
   # Replace all matches of regex with replacementText
   #
   # regex - A {RegExp} representing the text to find.