locations in LPeg messages on errors in grammars

lpegerr1.lua

local lpeg = require 'lpeg'

equalcount = lpeg.P{
  "S";   -- initial rule name
  S = "a" * lpeg.V"B" + "b" * lpeg.V"A" + "",
  A = "a" * lpeg.V"S" + "b" * lpeg.V"A" * lpeg.V"A",
  -- , '1' added to produce error
  B = "b", '1' * lpeg.V"S" + "a" * lpeg.V"B" * lpeg.V"B",
} * -1

lpegerr1.out

lua: lpeg-locations.lua:3: rule 'B' is not a pattern
stack traceback:
        [C]: in function 'P'
        lpeg-locations.lua:3: in main chunk
        [C]: ?

lpegerr2.lua

local lpeg = require 'lpeg'

equalcount = lpeg.P{
  "S";   -- initial rule name
  S = "a" * lpeg.V"B" + "b" * lpeg.V"A" + "",
  -- ++++ added to produce error
  A = "a" * lpeg.V"S++++" + "b" * lpeg.V"A" * lpeg.V"A",
  B = "b" * lpeg.V"S" + "a" * lpeg.V"B" * lpeg.V"B",
} * -1

lpegerr2.out

lua: lpeg-locations.lua:3: rule 'S++++' undefined in given grammar
stack traceback:
        [C]: in function 'P'
        lpeg-locations.lua:3: in main chunk
        [C]: ?