Shift-double-click expands the selection over the clicked word

Also factored `get(Beginning|End)OfCurrentWordBufferPosition` methods out of `moveTo(Beginning|End)OfWord` on Cursor. They are used by a `getCurrentWordBufferRange` method, which Selection now uses to find the range of the current word.

src/app/cursor.coffee

@@ -1,6 +1,7 @@
 {View} = require 'space-pen'
 Anchor = require 'anchor'
 Point = require 'point'
+Range = require 'range'
 _ = require 'underscore'
 
 module.exports =
@@ -93,19 +94,37 @@ class Cursor extends View
     @setBufferPosition(nextPosition or @editor.getEofPosition())
 
   moveToBeginningOfWord: ->
+    @setBufferPosition(@getBeginningOfCurrentWordBufferPosition())
+
+  moveToEndOfWord: ->
+    @setBufferPosition(@getEndOfCurrentWordBufferPosition())
+
+  getBeginningOfCurrentWordBufferPosition: (options = {}) ->
+    allowPrevious = options.allowPrevious ? true
+    position = null
     bufferPosition = @getBufferPosition()
     range = [[0,0], bufferPosition]
     @editor.backwardsTraverseRegexMatchesInRange @wordRegex, range, (match, matchRange, { stop }) =>
-      @setBufferPosition matchRange.start
+      position = matchRange.start
+      if not allowPrevious and matchRange.end.isLessThan(bufferPosition)
+        position = bufferPosition
       stop()
+    position
 
-  moveToEndOfWord: ->
+  getEndOfCurrentWordBufferPosition: (options = {}) ->
+    allowNext = options.allowNext ? true
+    position = null
     bufferPosition = @getBufferPosition()
     range = [bufferPosition, @editor.getEofPosition()]
-
     @editor.scanRegexMatchesInRange @wordRegex, range, (match, matchRange, { stop }) =>
-      @setBufferPosition matchRange.end
+      position = matchRange.end
+      if not allowNext and matchRange.start.isGreaterThan(bufferPosition)
+        position = bufferPosition
       stop()
+    position
+
+  getCurrentWordBufferRange: ->
+    new Range(@getBeginningOfCurrentWordBufferPosition(allowPrevious: false), @getEndOfCurrentWordBufferPosition(allowNext: false))
 
   moveToEndOfLine: ->
     { row } = @getBufferPosition()

src/app/editor.coffee

@@ -140,7 +140,10 @@ class Editor extends View
         else
           @setCursorScreenPosition(screenPosition)
       else if clickCount == 2
-        @compositeSelection.getLastSelection().selectWord()
+        if e.shiftKey
+          @compositeSelection.getLastSelection().expandOverWord()
+        else
+          @compositeSelection.getLastSelection().selectWord()
       else if clickCount >= 3
         @compositeSelection.getLastSelection().selectLine()
 

src/app/selection.coffee

@@ -160,21 +160,10 @@ class Selection extends View
     @retainSelection = false
 
   selectWord: ->
-    row = @cursor.getScreenPosition().row
-    column = @cursor.getScreenPosition().column
+    @setBufferRange(@cursor.getCurrentWordBufferRange())
 
-    { row, column } = @cursor.getBufferPosition()
-
-    line = @editor.buffer.lineForRow(row)
-    leftSide = line[0...column].split('').reverse().join('') # reverse left side
-    rightSide = line[column..]
-
-    regex = /^\w*/
-    startOffset = -regex.exec(leftSide)?[0]?.length or 0
-    endOffset = regex.exec(rightSide)?[0]?.length or 0
-
-    range = new Range([row, column + startOffset], [row, column + endOffset])
-    @setBufferRange range
+  expandOverWord: ->
+    @setBufferRange(@getBufferRange().union(@cursor.getCurrentWordBufferRange()))
 
   selectLine: (row=@cursor.getBufferPosition().row) ->
     rowLength = @editor.buffer.lineForRow(row).length