Re: New project LuaCURL v1.0 is up

[Rici Lake <lua@...>]

On 27-Jun-05, at 1:57 PM, Alexander Marinov wrote:

> LuaCURL is CURL 7.14.0 binding to Lua 5.x
> Home Page: http://luacurl.luaforge.net
> Download: http://luaforge.net/projects/luacurl/

Cool!

> Here is an example how it works:
>
> require("luacurl")
>
> c=curl.new()
>
> c:setopt(curl.OPT_WRITEFUNCTION, function (stream, buffer)
> 	if stream:write(buffer) then
> 		return string.len(buffer);
> 	end
> end);

Just off the top of my head, and without even having looked at your
implementation, I would personally recommend a slightly simpler API:

c:setopt("writefunction", function...
c:setopt("writedata", ..

There is no real point introducing option objects (which I'll
bet end up being integers); you could implement this with a
simple internal table which used the option names as keys
(and I would be tempted to use some sort of functional as
a value, presumably wrapped in a static structure
wrapped in a lightuserdata, since function pointers are
not coercible to void*'s); the functional would then
do whatever argument coercion was necessary, and then
issue the internal setopt.)

Actually, though, there is a good argument for a different type
of binding for the writefunction/writedata options. A more
Lua-like binding would be similar to LuaLDAP, where the perform
function returns a generator (a "future", if you prefer), and
the caller can do whatever they want with the resulting strings.

Consider an API something like this:

function geturl(url)
  local c = curl.new():setopt("url", url)
                      :setopt("connecttimeout", 15)

  local chunks = {}
  for chunk in c:perform() do
    table.insert(chunks, chunk)
  end
  if c:error() then
    -- handle the error
   else
    c:close()
    return table.concat(chunks)
  end
end

or

function saveurl(url, filename, progfn)
  local c = curl.new():setopt("url", url)
                      :setopt("connecttimeout", 15)
  if progfn then
    c:setopt("progressfunction", progfn)
  end
  c:setopt("noprogress", not progfn)

  local f = io.open(filename, "w")
  for chunk in c:perform() do
    f:write(chunk)
  end
  if c:error() then
    -- handle the error
    -- somehow delete the file
   else
    f:close()
  end
  c:close()
end

(The : trick only requires setopt to return self. I personally
like the style but others may disagree. Another approach to
the multitude of options would be to model them as a pseudo-table,
allowing both read and write access.)

> c:perform();
> c:close();

I presume the garbage collector would take care of closing?

> Please send me feedback with suggestions how to improve it, bug 
> reports etc.

Thanks, again. Looks like it will be very useful.