深拷贝，只需要对table类型进行递归拷贝即可，其他类型直接用赋值拷贝或浅拷贝。
还有，拷贝后的table应与原table具有相同的元表，and元表不需要递归拷贝。
function deepcopy( src )
local lookup_table = {}
local function _copy( object )
if type(object) ~= "table" then
return object
elseif lookup_table[object] then
return lookup_table[object]
end
<span class="kd">local</span> <span class="n">new_table</span> <span class="o">=</span> <span class="p">{}</span>
<span class="n">lookup_table</span><span class="p">[</span><span class="n">object</span><span class="p">]</span> <span class="o">=</span> <span class="n">new_table</span>
<span class="k">for</span> <span class="n">k</span><span class="p">,</span><span class="n">v</span> <span class="k">in</span> <span class="nb">pairs</span><span class="p">(</span><span class="n">object</span><span class="p">)</span> <span class="k">do</span>
<span class="c1">--table的key可以是任意基本类型，所以不仅需要对value进行递归拷贝，也要对key进行递归拷贝</span>
<span class="n">new_table</span><span class="p">[</span><span class="n">_copy</span><span class="p">(</span><span class="n">k</span><span class="p">)]</span> <span class="o">=</span> <span class="n">_copy</span><span class="p">(</span><span class="n">v</span><span class="p">)</span>
<span class="k">end</span>
<span class="c1">--设置元表</span>
<span class="k">return</span> <span class="nb">setmetatable</span><span class="p">(</span><span class="n">new_table</span><span class="p">,</span> <span class="nb">getmetatable</span><span class="p">(</span><span class="n">object</span><span class="p">))</span>
<span class="k">end</span>
<span class="k">return</span> <span class="n">_copy</span><span class="p">(</span><span class="n">src</span><span class="p">)</span>
end
local t = {a=3}
local tt = {
t1 = t,
t2 = t
}
local tcopy = deepcopy(tt)
print(t)
print(tt.t1, tt.t2)
print(tcopy.t1, tcopy.t2)
–输出
–table: 0074D710
–table: 0074D710 table: 0074D710
–table: 0074CAA0 table: 0074CAA0
–可以看到，tt里面的t1和t2其实是同一个table，所以进行深拷贝的时候要保持这种联系，而不是在深拷贝后里面变成两个独立的table，使用了lookup_table来保存已经拷贝过的对象。
–而且使用lookup_table还避免了下面这种情况
t.b = t – 有个索引指向自己，如果不用lookup_table的话保存的话会进入死循环
local t1 = deepcopy(t)
print(t.b, t1.b)
print(t, t1)
–输出
–table: 007EAEA8 table: 007ED1B8
–table: 007EAEA8 table: 007ED1B8