- It can detect macros that take rest parameters named body, then highlight and indent them correctly.
- It uses R5RS's grammar & mz-specific extensions to highlight numbers correctly -- even weird ones, like
[(+ a b])
"\x61b \t c\u0064\n"
You can check out more at http://arclanguage.org/item?id=10147 or http://bitbucket.org/fallintothis/arc-vim. It hasn't changed much since I first submitted it, though I've noticed it fails to highlight 0-argument function names like queue and new-fnid. Been meaning to fix that for awhile.