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-- Persistence library:

--   Memorize data for current function

--   memory.save(tab) and tab=memory.load()

--

--   The data will be stored in file called

--     .dat

--   in the lua directory

--

-- Example 1:

--

--  -- Load initial values or set defaults

--  arg = memory.load({picX=320,picY=200,scale=0})

--  -- Run an inputbox

--  OK,arg.picX,arg.picY,arg.scale = inputbox("Image Size")",

--    "Width",    arg.picX,  1,2048,0,

--    "Height",   arg.picY,  1,2048,0,

--    "Scale",    arg.scale, 0,1,0);

--  if OK == true then

--    -- Save the selected values

--    memory.save(arg)

--  end

-- Example 2:

--

--  -- Load initial values or set defaults

--  arg = memory.load({x=320,y=200,scale=0})

--  picX=arg.x

--  picY=arg.y

--  scale=arg.scale

--  -- Run an inputbox

--  OK,picX,picY,scale = inputbox("Image Size")",

--    "Width",    picX,  1,2048,0,

--    "Height",   picY,  1,2048,0,

--    "Scale",    scale, 0,1,0);

--  if OK == true then

--    -- Save the selected values

--    memory.save({x=picX,y=picY,scale=scale})

--  end

memory =

{

  serialize = function(o)

    if type(o) == "number" then

      return tostring(o)

    elseif type(o) == "string" then

      return string.format("%q", o)

    --elseif type(o) == "table" then

    --  io.write("{\n")

    --  for k,v in pairs(o) do

    --    io.write("  ", k, " = ")

    --    memory.serialize(v)

    --    io.write(",\n")

    --  end

    --  io.write("}\n")

    else

      error("cannot serialize a " .. type(o))

    end

  end;

  -- Return a string identifying the calling function.

  -- Pass 1 for parent, 2 for grandparent etc.

  callername = function(level)

    local w

    local last_slash

    local info = debug.getinfo(level+1,"Sn")

    local caller=tostring(info.name)

    -- Function name if possible

    if (caller~="nil") then

      return caller

    end

    -- Otherwise, get file name, without extension

    -- Get part after directory name

    last_slash=0

    while true do

      local pos = string.find(info.source, "/", last_slash+1)

      if (pos==nil) then break end

      last_slash=pos

    end

    while true do

      local pos = string.find(info.source, "\\", last_slash+1)

      if (pos==nil) then break end

      last_slash=pos

    end

    caller=string.sub(info.source, last_slash+1)

    -- Remove file extension

    if (string.sub(caller,-4, -1)==".lua") then

      caller=string.sub(caller, 1, -5)

    end

    return caller

  end;

  -- Memorize some parameters.

  save = function(o)

    local caller=memory.callername(2)

    --for k, v in pairs(o) do

    --    messagebox(tostring(k))

    --    messagebox(tostring(v))

    --end

    local f, e = io.open(caller..".dat", "w");

    if (f ~= nil) then

      f:write("Entry {\n")

      for k, v in pairs(o) do

        if (type(v)=="number") then

          f:write("  "..k.."="..memory["serialize"](v)..",\n")

        end

      end

      f:write("}\n")

      f:close()

    end

  end;

  -- Recover some saved parameters.

  load = function(o)

    local caller=memory.callername(2)

    local i

    function Entry (b)

      -- Adds (or replaces) values in arg with those from b

      for k, v in pairs(b) do

        o[k]=v

      end

    end

    local f = (loadfile(caller..".dat"))

    if (f ~= nil) then

      f()

    end

    return o

  end;

}

return memory