Fix MoonScript line numbers in error messages, for FAR Manager environment

fix_reverse_moonscript_lines.lua

--luacheck: globals lpeg debug.traceback_ ;new_globals debug.traceback
--luacheck: ignore 231/S
if select(2,...)>1 then return end --runonce

-- modified from https://github.com/leafo/moonscript/blob/master/moonscript/util.lua#L34
require"moonscript.util".pos_to_line = function(str, pos)
  local line = 1
  for _ in string.sub(str,1,pos):gmatch("\n") do
    line = line + 1
  end
  return line
end

-- modified from https://github.com/leafo/moonscript/blob/master/moonscript/errors.moon#L44
local rewrite_traceback
rewrite_traceback = function(text, err, thread)
  local line_tables = require("moonscript.line_tables")
  local V, S, Ct, C
  V, S, Ct, C = lpeg.V, lpeg.S, lpeg.Ct, lpeg.C
  local header_text = "stack traceback:"
  local Header, Line = V("Header"), V("Line")
  local Break = lpeg.S("\n")
  local g = lpeg.P({
    Header,
    Header = header_text * Break * Ct(Line ^ 1),
    Line = "\t" * C((1 - Break) ^ 0) * (Break + -1)
  })
  local cache = { }
  -- added ----------------
  local reverse_line_number = require"moonscript.errors".reverse_line_number
  local level = thread and 0 or 1
  local function getFullName (short_src, line)
    line = tonumber(line)
    repeat
      local info = debug.getinfo(unpack({thread,level,"Sl"}, thread and 1 or 2))
      if info and info.short_src==short_src then
        if info.currentline==line or info.linedefined==line
           or info.currentline==-1 and info.linedefined<line and info.lastlinedefined>=line then
          return info.source:match"^@(.+)"
        end
      end
      level = level+1
    until not info
    --far.Message("Unable to reverse traceback line", "MoonScript", nil, "w")--debug
  end
  local concat = table.concat
  -- enhanced ---------------
  local function rev (str,fname,line,trail)
    local fullname = fname and getFullName(fname,line)
    local tbl = fullname and line_tables["@" .. fullname]
    local rev_line = tbl and reverse_line_number(fullname, tbl, line, cache)
    return rev_line and str:gsub(":"..line..trail, (":%s (%s)%s"):format(rev_line, line, trail))
  end
  local function rewrite_single (trace)
    return trace
      :gsub('^((.-):(%d+)(:))', rev)
      :gsub('(: in function <(.-):(%d+)(>))$', rev)
  end
  -------------------------
  err = err and rewrite_single(err)
  local match = g:match(text)
  if not (match) then
    return nil
  end
  for i, trace in ipairs(match) do
    match[i] = rewrite_single(trace)
  end
  local parts = {
    err,
    header_text,
    "\t" .. concat(match, "\n\t")
  }
  if not err then table.remove(parts,1) end
  return concat(parts, "\n")
end

debug.traceback_ = debug.traceback_ or debug.traceback -- save original
-- based on https://github.com/leafo/moonscript/blob/master/bin/moon.moon#L83
function debug.traceback (...)
  local thread,err,level = ...
  if type(thread)~="thread" then
    thread,err,level = nil,...
  end
  if level~=nil and type(level)~="number" then
    far.Message("Unexpected traceback level type: "..type(level))
    level = nil
  end
  if select("#",...)>(thread and 1 or 0) and type(err)~="string" then
    -- standard traceback function behavior
    return err
  end
  if not thread then
    level = level and level+1 or 2
  end
  local trace = debug.traceback_(unpack({thread, "", level}, thread and 1 or 2))
  local util = require"moonscript.util"
  --local errors = require"moonscript.errors"
  --local truncated = errors.truncate_traceback(util.trim(trace))
  local truncated = util.trim(trace)
  return rewrite_traceback(util.trim(truncated), err, thread)
    or table.concat({ err, util.trim(trace) }, "\n")
end