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Wim Couwenberg wrote:
Also, it seems like it would be more efficient to use a table directly for a couple of reasons. First, the special code that must have been in place to handle a table directly would be faster than having to make a function call every time.
I did a simple test. I timed the following scripts in 4.0.1, 5.0.2 and 5.1-alpha: 

Lua 4.0.1 version:

    local t = {}
    for i = 1, 1e4 do t[i] = i*i end

    for i = 1, 1e4 do
      for k, v in t do end
    end

Lua 5.0.2 and 5.1-alpha version:

    local t = {}
    for i = 1, 1e4 do t[i] = i*i end

    for i = 1, 1e4 do
      for k, v in pairs(t) do end
    end

results:

Lua 4.0.1: ~7.3 seconds
Lua 5.0.2: ~15.2 seconds
Lua 5.1-alpha: ~16.1 seconds
That makes sense. In the first version, some implicit functions are being executed, which are faster than explicitly calling pairs(). Seems like a 2x improvement in this sort of thing is A Good Thing (tm). 


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