Memory-mapped files and more

There's a very early implementation at http://www.equi4.com/lux/lxyzlib.c (even the name has not been decided).

A little trial:

  local m=mmfile('testfile')
  print(m, tag(m))
  print(format("%d %x %d", mminfo(m)))
  print(mmsub(m))
  print(mmsub(m, 3))
  print(mmsub(m, -3))
  print(mmsub(m, 3, 6))
  print(mmsub(m, 3, -6))
  print(mmsub(m, -100, 100))

The output is:

  userdata(8): 0x82f1a10  8
  4012b000 28 3
  Wed Jan 31 17:15:34 PST 2001
  d Jan 31 17:15:34 PST 2001
  001
  d Ja
  d Jan 31 17:15:34 PST
  Wed Jan 31 17:15:34 PST 2001

The latest build includes MD5 and Zlib's compression + checksums. These operate on mem maps, and can therefore be used with Lua strings as well as memory-mapped files (or any other data structure). A ZIP archive scanner has been coded as example, it does not use file I/O.

-jcw