czlc · January 4, 2018 07:59 · Jan 4, 2018 · Jan 4, 2018
diff --git a/test.md → luacs.md b/test.md → luacs.md
diff --git a/test.md b/test.md
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+# Lua 代码风格指南
+
+## 格式化
+
+* 行首使用4字母缩进（Lua 推荐的是2字母）
+* 行长度不要超过80个字符
+* 不要用分号避免换行
+```lua
+-- bad
+local whatever = 'sure';
+a = 1; b = 2
+
+-- good
+local whatever = 'sure'
+a = 1
+b = 2
+```
+* 不要因为代码块较短，就写成一行
+```lua
+-- bad
+local print_table = function(t) for _,v in ipairs(t) do print(v) end end
+
+-- good
+local print_table = function(t) 
+    for _,v in ipairs(t) do 
+        print(v) 
+    end 
+end
+```
+* `{`，`}`，及所有运算符前后应留一个空格
+```lua
+-- bad
+local test={one=1}
+local thing=1
+thing = thing-1
+thing = thing*1
+thing = 'string'..'s'
+
+--good
+local test = { one = 1 }
+local thing = 1
+thing = thing - 1
+thing = thing * 1
+thing = 'string' .. 's'
+```
+* `(`， `)` 前后不留空格
+* 逗号后空一格
+* 代码块之间留一个空行
+```lua
+-- bad
+if thing then
+  -- ...stuff...
+end
+function derp()
+  -- ...stuff...
+end
+local wat = 7
+
+-- good
+if thing then
+  -- ...stuff...
+end
+
+function derp()
+  -- ...stuff...
+end
+
+local wat = 7
+```
+* 字符串推荐使用双引号(")
+
+## 命名规则
+
+* 作用范围越大的变量、函数，名字应该越具体（即越长）
+
+* 文件、变量、函数名称遵循`snake_case`规则
+
+>> https://en.wikipedia.org/wiki/Snake_case
+
+```lua
+-- bad
+local OBJEcttsssss = {}
+local thisIsMyObject = {}
+local this-is-my-object = {}
+
+local c = function()
+  -- ...stuff...
+end
+
+-- good
+local this_is_my_object = {}
+
+local function do_that_thing()
+  -- ...stuff...
+end
+```
+
+* 常量名称使用全大写字母，单词之间用下划线分隔
+```lua
+--good
+local MAX_COUNT = 200
+```
+
+* 下划线开头的变量名保留给lua内部使用，如`_G` 和 `_ENV`
+
+* 使用单下划线表示忽略的变量
+```lua
+--good
+for _, name in pairs(names) do
+  -- ...stuff...
+end
+```
+
+* 类、模块名称遵循`PascalCase`规则
+>> https://en.wikipedia.org/wiki/PascalCase
+
+```lua
+-- bad
+local date      = require('date')
+local mongo_obj = require "mongo_obj"
+
+-- good
+local Date     = require('date')
+local MongoObj = require "mongo_obj"
+```
+
+## 特性
+
+* 不要使用隐式类型转换
+```lua
+local input_value = '4'
+
+-- bad
+local total_score = review_score .. ''
+local val = input_value * 1
+
+-- good
+local total_score = tostring(review_score)
+local val = tonumber(input_value)
+```
+
+* 除了错误处理分支，尽量不用`debug`库
+
+## 变量
+
+* 变量声明时总是使用`local`, 避免产生全局变量
+* 不要定义不使用的变量；忽略的变量命名为`_`；
+* 不要使用未定义变量
+* 在作用域的顶部给变量赋值，避免随用随取
+
+```lua
+-- bad
+for _, item in ipairs(items) do
+    if item.score > player:get_score() then
+        -- do something
+    end
+end
+
+-- good
+local score = player:get_score()
+for _, item in ipairs(items) do
+    if item.score > score then
+        -- do something
+    end
+end
+```
+
+* 合理减小变量的作用域
+```lua
+-- bad
+local v, x, y, z
+if condition then
+  x = u2*v3-u3*v2
+  y = u3*v1-u1*v3
+  z = u1*v2-u2*v1
+  v = {x,y,z}
+end
+
+-- good
+local v
+if condition then
+  local x = u2*v3-u3*v2
+  local y = u3*v1-u1*v3
+  local z = u1*v2-u2*v1
+  v = {x,y,z}
+end
+```
+
+## 函数
+
+* 函数声明时总是使用`local`, 避免产生全局函数
+```lua
+-- bad
+function foo()
+    -- stuff
+end
+
+-- good
+local function foo()
+    -- stuff
+end
+```
+
+* 优先使用函数语法；避免产生匿名函数
+```lua
+-- bad
+local nope = function(name, options)
+  -- ...stuff...
+end
+
+-- good
+local function yup(name, options)
+  -- ...stuff...
+end
+```
+
+* 早失败，早返回; 减少嵌套层次；
+```lua
+-- bad
+local function is_good_name(name)
+    if #name >= 3 then
+        if #name <= 30 then
+            if not string.match(name, "%u") then
+                return true
+            end
+        end
+    end
+
+    return false
+end
+
+-- good
+local function is_good_name(name, options, args)
+    if #name < 3 or #name > 30 or string.match(name, "%u") then
+        return false
+    end
+
+    return true
+end
+```
+
+* 函数循环复杂度尽量低于10，不应超过15
+>> 循环复杂度定义: https://zh.wikipedia.org/wiki/%E5%BE%AA%E7%92%B0%E8%A4%87%E9%9B%9C%E5%BA%A6
+
+## 类
+* 建议优先使用`OOP`模式设计系统
+* 类的私有成员函数名字使用下划线开头
+* 模块不要直接返回非基类
+* 类的对象应使用同一个元表
+```lua
+-- bad
+-- foo.lua
+local mt = {}
+function mt:_do_foo()
+    -- stuff
+end
+
+function mt:foo()
+    -- stuff
+    self:_do_foo()
+    -- stuff
+end
+
+local M = {}
+function M.new_obj()
+    local obj = {
+        -- stuff
+    }
+    return setmetatable(obj, {__index=mt})
+end
+return M
+
+-- good
+-- foo.lua
+local mt = {}
+mt.__index = mt
+function mt:_do_foo()
+    -- stuff
+end
+function mt:foo()
+    -- stuff
+    self:_do_foo()
+    -- stuff
+end
+
+local M = {}
+function M.new_obj()
+    local obj = {
+        -- stuff
+    }
+    return setmetatable(obj, mt)
+end
+return M
+```
+
+* 外部不要直接访问/修改类的成员变量； 如果外部需要频繁访问类的成员变量，需要考虑一下类的内聚性。
+```lua
+-- bad
+local obj = new_obj()
+print(obj.score)
+obj.score = 5
+
+-- good
+local obj = new_obj()
+print(obj:get_score())
+obj:set_score(5)
+```
+
+## 模块
+
+* 模块总是返回一个`table`
+* 建议模块内待返回的`table`使用`local M = {}`声明方式
+
+## 头文件
+
+* 通过`require`引用的模块，应该按照通用性由高到底排序
+* 通用模块、业务模块、服务内模块之间应使用空行分隔
+
+```lua
+-- bad
+local RoomApi = require "room_api"
+local RoomConst = require "war_room.const"
+local Env = require "global"
+local Date = require "date"
+local Log = require "log"
+
+-- good
+local Log  = require "log"
+local Date = require "date"
+
+local RoomApi   = require "room_api"
+local RoomConst = require "war_room.const"
+
+local Env = require "global"
+```
+
+
+## skynet
+
+* 不要在循环中调用别的服务；`call`和`send`都应避免
+```lua
+-- bad
+for _, item in ipairs(items) do
+    Skynet.call(addr, "lua", "add_item", {item_id=item.item_id})
+end
+
+-- good
+local request = {}
+for _, item in ipairs(items) do
+    table.insert(request, {item_id=item.item_id})
+end
+Skynet.call(addr, "lua", "add_items", request)
+```
+
+* 不要在循环中进行`io`操作
+
+## 参考
+
+1. [Lua Style [email protected]](http://lua-users.org/wiki/LuaStyleGuide)
+2. [Lua Style [email protected]/Olivine-Labs](https://github.com/Olivine-Labs/lua-style-guide/blob/master/README.md)
+