file.lua

   1 -- primitives for saving to file and loading from file
   2 function file_exists(filename)
   3   local infile = App.open_for_reading(filename)
   4   if infile then
   5     infile:close()
   6     return true
   7   else
   8     return false
   9   end
  10 end
  11
  12 function load_from_disk(State)
  13   local infile = App.open_for_reading(State.filename)
  14   State.lines = load_from_file(infile)
  15   if infile then infile:close() end
  16 end
  17
  18 function load_from_file(infile)
  19   local result = {}
  20   if infile then
  21     local infile_next_line = infile:lines()  -- works with both Lua files and LÖVE Files (https://www.love2d.org/wiki/File)
  22     while true do
  23       local line = infile_next_line()
  24       if line == nil then break end
  25       table.insert(result, {data=line})
  26     end
  27   end
  28   if #result == 0 then
  29     table.insert(result, {data=''})
  30   end
  31   return result
  32 end
  33
  34 function save_to_disk(State)
  35   local outfile = App.open_for_writing(State.filename)
  36   if not outfile then
  37     error('failed to write to "'..State.filename..'"')
  38   end
  39   for _,line in ipairs(State.lines) do
  40     outfile:write(line.data)
  41     outfile:write('\n')
  42   end
  43   outfile:close()
  44 end
  45
  46 -- for tests
  47 function load_array(a)
  48   local result = {}
  49   local next_line = ipairs(a)
  50   local i,line,drawing = 0, ''
  51   while true do
  52     i,line = next_line(a, i)
  53     if i == nil then break end
  54     table.insert(result, {data=line})
  55   end
  56   if #result == 0 then
  57     table.insert(result, {data=''})
  58   end
  59   return result
  60 end
  61
  62 function is_absolute_path(path)
  63   local os_path_separator = package.config:sub(1,1)
  64   if os_path_separator == '/' then
  65     -- POSIX systems permit backslashes in filenames
  66     return path:sub(1,1) == '/'
  67   elseif os_path_separator == '\\' then
  68     if path:sub(2,2) == ':' then return true end  -- DOS drive letter followed by volume separator
  69     local f = path:sub(1,1)
  70     return f == '/' or f == '\\'
  71   else
  72     error('What OS is this? LÖVE reports that the path separator is "'..os_path_separator..'"')
  73   end
  74 end
  75
  76 function is_relative_path(path)
  77   return not is_absolute_path(path)
  78 end