Fix lint warnings: prefer single quoted strings

lib/nerdtree/path.vim

@@ -37,7 +37,7 @@ endfunction
 
 " FUNCTION: Path.bookmarkNames() {{{1
 function! s:Path.bookmarkNames()
-    if !exists("self._bookmarkNames")
+    if !exists('self._bookmarkNames')
         call self.cacheDisplayString()
     endif
     return self._bookmarkNames
@@ -87,22 +87,22 @@ function! s:Path.changeToDir()
     endif
 
     try
-        if g:NERDTreeUseTCD && exists(":tcd") == 2
-            execute "tcd " . dir
+        if g:NERDTreeUseTCD && exists(':tcd') == 2
+            execute 'tcd ' . dir
             call nerdtree#echo("Tab's CWD is now: " . getcwd())
         else
-            execute "cd " . dir
-            call nerdtree#echo("CWD is now: " . getcwd())
+            execute 'cd ' . dir
+            call nerdtree#echo('CWD is now: ' . getcwd())
         endif
     catch
-        throw "NERDTree.PathChangeError: cannot change CWD to " . dir
+        throw 'NERDTree.PathChangeError: cannot change CWD to ' . dir
     endtry
 endfunction
 
 " FUNCTION: Path.compareTo() {{{1
 "
 " Compares this Path to the given path and returns 0 if they are equal, -1 if
-" this Path is "less than" the given path, or 1 if it is "greater".
+" this Path is 'less than' the given path, or 1 if it is 'greater'.
 "
 " Args:
 " path: the path object to compare this to
@@ -188,7 +188,7 @@ endfunction
 " dest: the location to copy this dir/file to
 function! s:Path.copy(dest)
     if !s:Path.CopyingSupported()
-        throw "NERDTree.CopyingNotSupportedError: Copying is not supported on this OS"
+        throw 'NERDTree.CopyingNotSupportedError: Copying is not supported on this OS'
     endif
 
     call s:Path.createParentDirectories(a:dest)
@@ -199,10 +199,10 @@ function! s:Path.copy(dest)
         let cmd_prefix = (self.isDirectory ? g:NERDTreeCopyDirCmd : g:NERDTreeCopyFileCmd)
     endif
 
-    let cmd = cmd_prefix . " " . escape(self.str(), self._escChars()) . " " . escape(a:dest, self._escChars())
+    let cmd = cmd_prefix . ' ' . escape(self.str(), self._escChars()) . ' ' . escape(a:dest, self._escChars())
     let success = system(cmd)
     if v:shell_error != 0
-        throw "NERDTree.CopyError: Could not copy ''". self.str() ."'' to: '" . a:dest . "'"
+        throw "NERDTree.CopyError: Could not copy '". self.str() ."' to: '" . a:dest . "'"
     endif
 endfunction
 
@@ -286,7 +286,7 @@ endfunction
 " Returns a string that specifies how the path should be represented as a
 " string
 function! s:Path.displayString()
-    if self.cachedDisplayString ==# ""
+    if self.cachedDisplayString ==# ''
         call self.cacheDisplayString()
     endif
 
@@ -295,7 +295,7 @@ endfunction
 
 " FUNCTION: Path.edit() {{{1
 function! s:Path.edit()
-    exec "edit " . self.str({'format': 'Edit'})
+    exec 'edit ' . self.str({'format': 'Edit'})
 endfunction
 
 " FUNCTION: Path.extractDriveLetter(fullpath) {{{1
@@ -306,7 +306,7 @@ function! s:Path.extractDriveLetter(fullpath)
         if a:fullpath =~ '^\(\\\\\|\/\/\)'
             "For network shares, the 'drive' consists of the first two parts of the path, i.e. \\boxname\share
             let self.drive = substitute(a:fullpath, '^\(\(\\\\\|\/\/\)[^\\\/]*\(\\\|\/\)[^\\\/]*\).*', '\1', '')
-            let self.drive = substitute(self.drive, '/', '\', "g")
+            let self.drive = substitute(self.drive, '/', '\', 'g')
         else
             let self.drive = substitute(a:fullpath, '\(^[a-zA-Z]:\).*', '\1', '')
         endif
@@ -413,7 +413,7 @@ endfunction
 " FUNCTION: Path.getSortKey() {{{1
 " returns a key used in compare function for sorting
 function! s:Path.getSortKey()
-    if !exists("self._sortKey") || g:NERDTreeSortOrder !=# g:NERDTreeOldSortOrder
+    if !exists('self._sortKey') || g:NERDTreeSortOrder !=# g:NERDTreeOldSortOrder
         " Look for file metadata tags: [[timestamp]], [[extension]], [[size]]
         let metadata = []
         for tag in g:NERDTreeSortOrder
@@ -501,7 +501,7 @@ function! s:Path.ignore(nerdtree)
         endfor
 
         for Callback in g:NERDTree.PathFilters()
-            let Callback = type(Callback) == type(function("tr")) ? Callback : function(Callback)
+            let Callback = type(Callback) == type(function('tr')) ? Callback : function(Callback)
             if Callback({'path': self, 'nerdtree': a:nerdtree})
                 return 1
             endif
@@ -637,8 +637,8 @@ function! s:Path.readInfoFromDisk(fullpath)
 
     let fullpath = s:Path.WinToUnixPath(a:fullpath)
 
-    if getftype(fullpath) ==# "fifo"
-        throw "NERDTree.InvalidFiletypeError: Cant handle FIFO files: " . a:fullpath
+    if getftype(fullpath) ==# 'fifo'
+        throw 'NERDTree.InvalidFiletypeError: Cant handle FIFO files: ' . a:fullpath
     endif
 
     let self.pathSegments = filter(split(fullpath, '/'), '!empty(v:val)')
@@ -650,7 +650,7 @@ function! s:Path.readInfoFromDisk(fullpath)
         let self.isDirectory = 0
         let self.isReadOnly = filewritable(a:fullpath) ==# 0
     else
-        throw "NERDTree.InvalidArgumentsError: Invalid path = " . a:fullpath
+        throw 'NERDTree.InvalidArgumentsError: Invalid path = ' . a:fullpath
     endif
 
     let self.isExecutable = 0
@@ -700,7 +700,7 @@ endfunction
 " Renames this node on the filesystem
 function! s:Path.rename(newPath)
     if a:newPath ==# ''
-        throw "NERDTree.InvalidArgumentsError: Invalid newPath for renaming = ". a:newPath
+        throw 'NERDTree.InvalidArgumentsError: Invalid newPath for renaming = '. a:newPath
     endif
 
     call s:Path.createParentDirectories(a:newPath)
@@ -742,7 +742,7 @@ endfunction
 " value associated with 'truncateTo'. A '<' is prepended.
 function! s:Path.str(...)
     let options = a:0 ? a:1 : {}
-    let toReturn = ""
+    let toReturn = ''
 
     if has_key(options, 'format')
         let format = options['format']
@@ -883,13 +883,13 @@ function! s:Path.WinToUnixPath(pathstr)
     let toReturn = a:pathstr
 
     "remove the x:\ of the front
-    let toReturn = substitute(toReturn, '^.*:\(\\\|/\)\?', '/', "")
+    let toReturn = substitute(toReturn, '^.*:\(\\\|/\)\?', '/', '')
 
     "remove the \\ network share from the front
-    let toReturn = substitute(toReturn, '^\(\\\\\|\/\/\)[^\\\/]*\(\\\|\/\)[^\\\/]*\(\\\|\/\)\?', '/', "")
+    let toReturn = substitute(toReturn, '^\(\\\\\|\/\/\)[^\\\/]*\(\\\|\/\)[^\\\/]*\(\\\|\/\)\?', '/', '')
 
     "convert all \ chars to /
-    let toReturn = substitute(toReturn, '\', '/', "g")
+    let toReturn = substitute(toReturn, '\', '/', 'g')
 
     return toReturn
 endfunction