Behavior Tree 用 Lua 实现一个最简行为树

local SELECTOR = 1
local SEQUENCE = 2
local CONDITION = 3
local ACTION = 4

local function Traverse(node, ...)
    local t = node.type
    if t == SELECTOR then
        for i=1, #node do
            if Traverse(node[i], ...) then
                return true
            end
        end
        return false
    elseif t == SEQUENCE then
        for i=1, #node do
            if not Traverse(node[i], ...) then
                return false
            end
        end
        return true
    elseif t == CONDITION then
        for i=1, #node do
            if not node[i](...) then
                return false
            end
        end
        return true
    elseif t == ACTION then
        for i=1, #node do
            node[i](...)
        end
        return true
    end
end

local root =
{
    type = SELECTOR,
    {
        type = SEQUENCE,
        {
            type = CONDITION,
            function(i,j) return math.random() > i end,
            function(i,j) return math.random() < j end,
        },
        {
            type = ACTION,
            function() print("random") end,
        },
    },
    {
        type = ACTION,
        function() print("idle") end,
    },
}

local input1 = 0.2
local input2 = 0.7
Traverse(root, input1, input2)

有没有比 C++ 代码简单一万倍，有没有？ 

https://github.com/hangj/BehaviorTree