code: def count_values(tokens):
      
      ntoks = 0
      for tok in tokens:
          if tok in ('=', '/', '$', '&'):
              if ntoks > 0 and tok == '=':
                  ntoks -= 1
              break
          elif tok in whitespace + ',':
              continue
          else:
              ntoks += 1
  
      return ntoks
docs: Identify the number of values ahead of the current token.