mark-sexp marks more than sexp within comment blocks

[vellvisher]

Example code with cursor as []:

  // []Start my application.  
  public func application(

Hit C-M-SPC, C-M-@ or mark-sexp, marked region in between []

  // [Start my application.  
  public] func application(

Expected (eg from objc-mode)

  // [Start] my application.  
  public func application(

[taku0]

mark-sexp and forward/backward-sexp assume the point is not in a comment or string. We can define some reasonable behavior for such situation. forward-sexp-function is not defined for fundamental-mode nor text-mode. So we must define what is a expected behavior:

• marking a word
• marking from the point to the end of the comment/string
• marking the whole comment/string
• marking a word or balanced brackets (what if the brackets is not balanced?)
• marking a Swift token or balanced brackets