Re: file proxy?

[Tom N Harris <telliamed@...>]

On 2/12/2010 12:13 PM, spir wrote:
> Hello,
>
> I'm looking for a way to "subtype" Lua files, for file objects to
> hold additional attributes. It seems I cannot directly set attributes
> on Lua Files, since they are userdata. Is there a way to write a
> custom file type that delegates file methods to an actual Lua file
> (open in mode 'r')? My trials using __index with a table or function
> launch errors like:

One way would be a global table for file attributes with the file 
handles as weak keys.

FileAttributes = setmetatable({}, {__mode="k"})
function setfileattr(F,K,V)
  local FAT = FileAttributes[F] or {}
  FAT[K] = V
  FileAttributes[F] = FAT -- in case a new table is created
end
function getfileattr(F,K)
  return (FileAttributes[F] or {})[K]
end

--
- tom
telliamed@whoopdedo.org