正如其他人所说,这在很大程度上取决于您对等效性的定义。
如果你希望这是真的:
local t1 = {[{}] = {1}, [{}] = {2}}
local t2 = {[{}] = {1}, [{}] = {2}}
assert( table_eq(t1, t2) )
如果这样做,那么每次 t1 中的键是一个表时,您都必须
检查它与 t2 中每个表键的等价性,并通过以下方式尝试它们
一。这是一种方法(为了可读性而省略了元表内容)。
function table_eq(table1, table2)
local avoid_loops = {}
local function recurse(t1, t2)
-- compare value types
if type(t1) ~= type(t2) then return false end
-- Base case: compare simple values
if type(t1) ~= "table" then return t1 == t2 end
-- Now, on to tables.
-- First, let's avoid looping forever.
if avoid_loops[t1] then return avoid_loops[t1] == t2 end
avoid_loops[t1] = t2
-- Copy keys from t2
local t2keys = {}
local t2tablekeys = {}
for k, _ in pairs(t2) do
if type(k) == "table" then table.insert(t2tablekeys, k) end
t2keys[k] = true
end
-- Let's iterate keys from t1
for k1, v1 in pairs(t1) do
local v2 = t2[k1]
if type(k1) == "table" then
-- if key is a table, we need to find an equivalent one.
local ok = false
for i, tk in ipairs(t2tablekeys) do
if table_eq(k1, tk) and recurse(v1, t2[tk]) then
table.remove(t2tablekeys, i)
t2keys[tk] = nil
ok = true
break
end
end
if not ok then return false end
else
-- t1 has a key which t2 doesn't have, fail.
if v2 == nil then return false end
t2keys[k1] = nil
if not recurse(v1, v2) then return false end
end
end
-- if t2 has a key which t1 doesn't have, fail.
if next(t2keys) then return false end
return true
end
return recurse(table1, table2)
end
assert( table_eq({}, {}) )
assert( table_eq({1,2,3}, {1,2,3}) )
assert( table_eq({1,2,3, foo = "fighters"}, {["foo"] = "fighters", 1,2,3}) )
assert( table_eq({{{}}}, {{{}}}) )
assert( table_eq({[{}] = {1}, [{}] = {2}}, {[{}] = {1}, [{}] = {2}}) )
assert( table_eq({a = 1, [{}] = {}}, {[{}] = {}, a = 1}) )
assert( table_eq({a = 1, [{}] = {1}, [{}] = {2}}, {[{}] = {2}, a = 1, [{}] = {1}}) )
assert( not table_eq({1,2,3,4}, {1,2,3}) )
assert( not table_eq({1,2,3, foo = "fighters"}, {["foo"] = "bar", 1,2,3}) )
assert( not table_eq({{{}}}, {{{{}}}}) )
assert( not table_eq({[{}] = {1}, [{}] = {2}}, {[{}] = {1}, [{}] = {2}, [{}] = {3}}) )
assert( not table_eq({[{}] = {1}, [{}] = {2}}, {[{}] = {1}, [{}] = {3}}) )