Re: Syntax and redundancy
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- Subject: Re: Syntax and redundancy
- From: Rici Lake <lua@...>
- Date: 2005年8月30日 11:45:15 -0500
On 30-Aug-05, at 11:22 AM, Chris Marrin wrote:
I would do it like this:
local l = { }
... fill the list
local p = l
while p ~= nil do
...
p = p.next
end
Any nicer ways?
Write an iterator function.
do
local function nextlist(field, l)
return l and l[field]
end
function eachlist(l, field)
field = field or "next"
return nextlist, field, {[field] = l}
end
end
list = {"a", next = {"b", next = {"c"}}}
for l in eachlist(list) do print(l[1]) end
-- maybe I didn't want to use "next"
list = {"a", parent = {"b", parent = {"c"}}}
for l in eachlist(list, "parent") do print(l[1]) end
Whether that's nicer or not depends on your perspective, I guess. The
redundant table constructor is a bit irritating, and in any event it's
going to be somewhat slower than the while loop. On the other hand,
it's a nice simple syntax which makes it easy to see what's going on.
(Open to being criticised for doing the Lua equivalent of Boyko's DO
macro)
R
- References:
- Syntax and redundancy, Gavin Wraith
- Re: Syntax and redundancy, Philippe Lhoste
- Re: Syntax and redundancy, Rob Kendrick
- Re: Syntax and redundancy, David Olofson
- Re: Syntax and redundancy, Rici Lake
- Re: Syntax and redundancy, Aaron Brown
- Re: Syntax and redundancy, Adrian Perez
- Re: Syntax and redundancy, Rici Lake
- Re: Syntax and redundancy, Adrian Perez
- Re: Syntax and redundancy, Chris Marrin