【高级技巧】递归护栏：递归遍历的层级上限与降级

local function deepWalk(tbl, visit, depth, maxDepth, visited)
    depth = depth or 0
    visited = visited or {}
    if depth > (maxDepth or 32) then
        return visit("层数超限", nil, depth)
    end
    if type(tbl) ~= "table" then
        return visit(nil, tbl, depth)
    end
    if visited[tbl] then
        return visit("循环引用", nil, depth)
    end
    visited[tbl] = true
    for k, v in pairs(tbl) do
        if type(v) == "table" then
            deepWalk(v, visit, depth + 1, maxDepth, visited)
        else
            visit(k, v, depth)
        end
    end
end

local function dumpGear(actor, gearTree)
    actor = getplayerbyname(actor)
    deepWalk(gearTree, function(k, v, depth)
        local pad = string.rep("  ", depth)
        if k == "循环引用" or k == "层数超限" then
            sendmsg(actor, 1, pad .. "[" .. k .. "]")
        else
            sendmsg(actor, 1, pad .. tostring(k) .. " = " .. tostring(v))
        end
    end)
end