ComputerCraft Tutorial: logging_API_0_4

--############################
-- logging API
-- version 0.4c
-- http://hevohevo.hatenablog.com/

-- ### how to use
--[[
os.loadAPI("logging")

-- default logfile name is "mylog"
logging.forward() -- turtle.fowrard() and logging
logging.back()
logging.up()
logging.down()
logging.turnRight()
logging.turnLeft()

-- change logfile
logging.changeLogfile("mylog2")

-- write a log forcibly
logging.write("-- my message!!")

-- createLoggedFunc(function, succeeded_log, *failed_log)
-- return a function which writes succeeded/failed msg to a logfile
-- if you omit "failed_log" argument, succeeded_log is written in true/false cases
myRefuel = logging.createLoggedFunc(turtle.refuel, "turtle.refuel()")
myRefuel()

-- make a reverted log file, and return start position by running REV_FILE
logging.forward()
logging.turnRight()
logging.up()

local rev_filename = logging.makeRevFile()
shell.run(rev_filename)
--]]

-- ###########################
-- config
LOG_FILE = "mylog"
REV_FILE = "myrev"

TRANS_TBL = {}
TRANS_TBL["turtle.forward()"] = "turtle.back()"
TRANS_TBL["turtle.back()"] = "turtle.forward()"
TRANS_TBL["turtle.up()"] = "turtle.down()"
TRANS_TBL["turtle.down()"] = "turtle.up()"
TRANS_TBL["turtle.turnRight()"] = "turtle.turnLeft()"
TRANS_TBL["turtle.turnLeft()"] = "turtle.turnRight()"


-- ###########################
-- functions
function write(message)
  local fh = fs.open(LOG_FILE, "a")
  fh.writeLine(message)
  fh.close()
end

function backupFile(filename, tail_str)
  local tail_str = tail_str or "-bak"
  if fs.exists(filename) then
    fs.delete(filename..tail_str)
    fs.move(filename, filename..tail_str)
    return true
  else
    return false, "File doesn't exist"
  end
end

local function readTrans(filename, trans_tbl)
  local fh = fs.open(filename, 'r')
  local tmp_tbl = {}
  repeat
    local line = fh.readLine()
    local tLine = TRANS_TBL[line]
    if tLine then
      table.insert(tmp_tbl, tLine)
    end
  until not line
  fh.close()
  return tmp_tbl
end

local function reverseWrite(my_array, filename)
  local fh = fs.open(filename, 'a')
  for i=#my_array,1,-1 do
    if my_array[i] then fh.writeLine(my_array[i]) end
  end
  fh.close()
end

function makeRevFile(log_filename, rev_filename)
  local log_filename = log_filename or LOG_FILE
  local rev_filename = rev_filename or REV_FILE
  reverseWrite(readTrans(log_filename, TRANS_TBL), rev_filename)
  return rev_filename
end

-- return a function which writes succeeded/failed msg to a logfile
function createLoggedFunc(func, succeeded_log, failed_log)
  failed_log = failed_log or succeeded_log
  return function(...)
    local status, error_msg = func(...)
    if status then
      write(succeeded_log)
    else
      write(failed_log)
    end
    return status, error_msg
  end
end

-- redefine six movement functions in Turtle API
forward = createLoggedFunc(turtle.forward, "turtle.forward()", "-- turtle.forward()")
back = createLoggedFunc(turtle.back, "turtle.back()", "-- turtle.back()")
up = createLoggedFunc(turtle.up, "turtle.up()", "-- turtle.up()")
down = createLoggedFunc(turtle.down, "turtle.down()", "-- turtle.down()")
turnRight = createLoggedFunc(turtle.turnRight, "turtle.turnRight()")
turnLeft = createLoggedFunc(turtle.turnLeft, "turtle.turnLeft()")