Re: Proposal: Virtualization of Filesystem Operations for Lua 5.2.

[Georg Lehner <jorge-lua@...>]

Hello!

On 11/02/11 21:02, Luiz Henrique de Figueiredo wrote:
> > - open(path,"d+") creates a directory
> > - open(path,"d"[,attributes]) returns an iterator over the directory path,
> >    returning filenames of existing files matching the attributes table
> >      
> Interesting but perhaps it is not a good idea to overload open when mkdir
> exists and also readdir etc.
>    
mkdir and readdir seem not to exist in the core Lua libraries - at least 
I did not find them.

I tried not to add new functions, to keep the interface small - however 
I have no strong opinion
with respect to splitting file and directory manipulation into different 
functiongroups or
maintain them merged together.

I like the io.lines(path) functionality for iterating over files, so I 
guessed iterating over
directories should operate in a similar way, hence open(path,"d") 
returns an iterator.  It could
also be named readdir(path) or anything similar of course.

Note:  My proposal, and the Proof-Of-Concept module are named "fs" and 
containd all functions for
file and directory manipulation:  fs.open(), fs.close(), fs.flush(), 
fs.read(), fs.write(), ...

io.write() or os.remove() would not necessarily go away,  they would 
rather be wrapped eventually
inside fs.write(), fs.remove().


> > - remove(path) also removes (empty) directories
> >      
> os.remove already does that, at least under POSIX. I don't know about Windows.
>
> Perhaps your proposal can be first fleshed out as a working library
> so that we evaluate it...
>
>    
Thats why I offer a Proof-Of-Concept module for the higher level 
(fs.lua) and the lower level
functions (fsio.lua), see:

http://sw.magma.com.ni/LuaFs

Writing a module which reads/writes/iterates over a Lua table should be 
trivial too and could
illustriate some points, e.g. persistence of tables simply by a 
recursive file copy operation.
Somebody interested?


Regards,

    Jorge-León