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lua

其他-Lua 3d表缺少对象永久性(键值与表数据不一致)

(其他 - Lua 3d table lacks object permanence (key values do not consistently match to table data))

发布于 2020-12-02 22:57:51

因此,我在Lua方面遇到了一个奇怪的问题,我使用以下函数从名为Cube的全局3D“数组”中进行设置,读取和写入。但是,似乎每次读取或写入此“数组”时,尽管Cube是全局变量,但数据仅存储在该函数使用的实例上,不能说我以前从未遇到过,非常奇怪。

-- stole this one from: https://stackoverflow.com/questions/27976526/using-a-coordinate-pair-as-a-key-in-a-lua-table
-- basically the intended use is to store a 2d table of block information for the level the turtle is on

function setUpLevel()
    local test = {_props = {}}
    local mt = {}


    local function coord2index(x, z)
        return ((x-1) * xMax) + z
    end

    mt.__index = function(s, k)
        if s._props[coord2index(k[1], k[2])] ~= nil then
            return s._props[coord2index(k[1], k[2])]
        end
    end

    mt.__newindex = function(s, k, v)
    s._props[coord2index(k[1], k[2])] = v 
    end
    mt.__call = function (t, k)
        if type(k) == "table" then print "Table" end
    end

    setmetatable(test, mt)
    return test
    --test[{1,2}] = 5
end

function setupCube()
    local cube = {}
    cube[relY]=setUpLevel()
    return cube
end

Cube = setupCube()

function readCubeData(x,y,z)
    if (Cube[y]==nil) then
        return nil
    end
    -- debug
    return Cube[y][{x,z}]
end

function storeCubeData(x,y,z,data)
    if (readCubeData(x,y,z)==nil) then
        Cube[y]=setUpLevel()
    end



    Cube[y][{x,z}]=data
    data= readCubeData(x,y,z)
    print (x,",",y,",",z,":",readCubeData(x,y,z))
    sleep(.5)
end

输出示例:

中的print语句storeCubeData()将提供的正确输出(顺序无关紧要,仅将数据对应到x,y,z值) 该图显示了在storeCubeData()中使用时readCubeData()函数的输出

但是下面的打印语句 start()

function start()
    detectAndStore()
    print("=============")
    sleep(1)
    data= readCubeData(0,relY,1)
    print (0,",",relY,",",1,":",readCubeData(0,relY,1))
    sleep(.5)
    data= readCubeData(-1,relY,0)
    print (-1,",",relY,",",0,":",readCubeData(-1,relY,0))
    sleep(.5)
    data= readCubeData(0,y,-1)
    print (0,",",relY,",",-1,":",readCubeData(0,relY,-1))
    sleep(.5)
    data= readCubeData(1,y,0)
    print (1,",",relY,",",0,":",readCubeData(1,relY,0))
    sleep(.5)
end
start()

会产生一个输出 start()函数的输出,错误的输出,x,y,z值与应该包含在其中的数据之间的不匹配

这只是悲剧性的错误,x,y,z值未指向正确的值,并且表也不打算在相同的x,y,z位置重复。我真的无法为我的生命解决这个问题

Questioner
Percy Jackson
Viewed
0
Alexander Mashin 2020-12-04 09:43:13

错误在if (readCubeData(x,y,z)==nil) thenstoreCubeData(x,y,z,data)每当你尝试在其中存储新信息时,你都将覆盖整个“级别”。应该是if (Cube [y] == nil) then整个if语句可以进一步简化为Cube [y] = Cube [y] or setUpLevel ()

另外,if s._props[coord2index(k[1], k[2])] ~= nil then没有必要;功能可以定义为本地;并且hash函数coord2index将导致冲突(例如coord2index (1, 5) == coord2index (2, -5)if xMax == 10),因此将其替换为@Egor Skriptunoff所说的。