a1b2f4e0893cdcc34b6bd58a6474582b8afc96e3
   1<start> and <end> can take one of these forms:
   2
   3- number
   4+
   5If <start> or <end> is a number, it specifies an
   6absolute line number (lines count from 1).
   7+
   8
   9- /regex/
  10+
  11This form will use the first line matching the given
  12POSIX regex.  If <end> is a regex, it will search
  13starting at the line given by <start>.
  14+
  15
  16- +offset or -offset
  17+
  18This is only valid for <end> and will specify a number
  19of lines before or after the line given by <start>.
  20
  21+
  22If ``:<regex>'' is given in place of <start> and <end>, it denotes the range
  23from the first funcname line that matches <regex>, up to the next
  24funcname line.