[Date Prev][Date Next][Thread Prev][Thread Next]
[Date Index]
[Thread Index]
- Subject: Re: Accessing table entries with iterators
- From: Javier Guerra <javier@...>
- Date: Mon, 16 Jan 2006 17:14:24 -0500
On Monday 16 January 2006 3:59 pm, Henderson, Michael D wrote:
> The PIL says, "With proper iterators, we can traverse almost anything,
> and do it in a readable fashion." I guess that I'm just not
> understanding iterators.
>
> If I have an entry like the following
>
> entry = { timestamp = "2006/01/16 132155"
> , { "cpu" , 42.3 }
> , { "fan" , 5823 }
> , { "aaa" , "bbb" }
> };
>
.... snip......
>
> Which leads me to another question. Is there a better way to write this?
i like to write coroutine iterators (UNTESTED):
function get_iter (t)
return coroutine.wrap (function ()
if not t.timestamp then
error ("missing timestamp")
end
for _, v in ipairs (t) do
if (type (v) ~= "table" or not (v[1] and v[2])) then
error ("bad entry")
end
coroutine.yield (v[1], v[2])
end
end)
end
might be a bit slower than a handcoded state machine, but much easier to read
i wonder why you want the timestamp test in the iterator..., maybe it would be
better in the iterator factory:
function get_iter (t)
if not t.timestamp then
error ("missing timestamp")
end
return coroutine.wrap (function ()
for _, v in ipairs (t) do
if (type (v) ~= "table" or not (v[1] and v[2])) then
error ("bad entry")
end
coroutine.yield (v[1], v[2])
end
end)
end
--
Javier
Attachment:
pgpjs9Sf0WULb.pgp
Description: PGP signature