使用布尔值表对 lua 表进行排序

Question

我搜索了高低，并试图在不同的阶段实现这一目标。 我正在尝试对基于另一个表值的几个表进行排序。我尝试通过播种 k, v 来对这些表进行排序，其中 v 是布尔值。

这是我到目前为止所得到的。提前感谢您的帮助。

function byInstallsField(x,y) 
  -- cant seem to make sens out of the sorting 
  if x.installed then return true
  elseif y.installed == false then return false
  end
end

-- var is the index passed into the function
-- pRect:new is a custom lib for rect' drawing  

playerRect[ var ] = pRect:new(_W  + dimesion_for_rect * var, 0, 
                              dimesion_for_rect, 
                              dimesion_for_rect, 
                              3 ) -- _x, _y , _hieght, _width, round 

playerRect.installed = inst;
table.sort( playerRect, byInstallsField )

downloadedImage[ var ] = fb_friends:new(var, imageOnFile, 
                                        playerRect[ var ].x, 
                                        playerRect[ var ].y,
                                        0.25, 0.25, 0, dimesion_for_rect - 5)
downloadedImage[ var ].id = var
downloadedImage.installed = inst 
table.sort( downloadedImage, byInstallsField )

我希望对 playerRect 和下载的图像表进行排序的结果，以便安装的 that = true 将引导数组..

播放器 1.installed = true ，播放器 2.installed = true ，播放器 3.installed = false

Answer 1

给table.sort的比较函数必须满足严格排序关系。特别是，给定a 和b，如果byInstall(a, b) 为真，那么byInstall(b, a) 必须返回假。

这是一个简单的例子：

local player = {
  {"alice", installed = false},
  {"bob", installed = true},
  {"carol", installed = true},
  {"dave", installed = true},
  {"matthew", installed = false},
  {"steve", installed = true},
}

function byInstall(first, second)
  return first.installed and not second.installed
end

table.sort(player, byInstall)

排序后，installed = true 的子表将被组合在一起。表player 将如下所示：

{
  {
    "steve",
    installed = true
  },
  {
    "dave",
    installed = true
  },
  {
    "carol",
    installed = true
  },
  {
    "bob",
    installed = true
  },
  {
    "matthew",
    installed = false
  },
  {
    "alice",
    installed = false
  }
}