This form will use the first line matching the given
POSIX regex. If <start> is a regex, it will search from the end of
the previous `-L` range, if any, otherwise from the start of file.
+If <start> is ``^/regex/'', it will search from the start of file.
If <end> is a regex, it will search
starting at the line given by <start>.
+
+
If ``:<regex>'' is given in place of <start> and <end>, it denotes the range
from the first funcname line that matches <regex>, up to the next
-funcname line.
+funcname line. ``:<regex>'' searches from the end of the previous `-L` range,
+if any, otherwise from the start of file.
+``^:<regex>'' searches from the start of file.