lua高级

生产者-消费者

function producer()
    return coroutine.create(
    function (salt)
        local t = { 1, 2, 3 }
        for i = 1, #t do
            salt =
            coroutine.yield(t[i] + salt)
        end
    end
    )
end


function consumer(prod)
    local salt = 10
    while true do
        local running, product =
        coroutine.resume(prod, salt)
        salt = salt * salt
        if running then
            print(product or "END!")
        else
            break
        end
    end
end
consumer(producer())

结果：
11
102
10003
END!
[Finished in 0.5s]

面向对象的调用

function createFoo(name)
    local data = { name = name }
    local obj = {}

    function obj.SetName(name)
        data.name = name
    end

    function obj.GetName()
        return data.name
    end

    return obj
end
o = createFoo("Sam")
print("name:", o.GetName())
o.SetName("Lucy")
print("name:", o.GetName())
print("name:", o.GetName())

结果：
name: Sam
name: Lucy
name: Lucy
[Finished in 0.1s]

lua中的setmetatable

local t = {}
local t2 = { a = " and ", b = "Li Lei", c = "Han Meimei" }
local m = { __index = t2}
setmetatable(t, m) --设表m为表t的元表

print(t.b,t.a,t.c)

结果：
Li Lei and Han Meimei
[Finished in 0.1s]

lua中的正则表达式

local uri = "http://aaaa.api.bbbb.com/user_pic/get?b_auto_id=1111&user_id=2222"
local pmatch = string.gmatch( uri,"/?([%l%d-_]+)/?" )
for w in pmatch do 
    print(w)
end

http
aaaa
api
bbbb
com
user_pic
get
b_auto_id
1111
user_id
2222
[Finished in 0.1s]

local s = "hello world from lua"
local d = "hello = world, from= lua"
for w in string.gmatch(d, "%a+%s*=%s*%a+") do
    print(w)   --匹配0个或者多个空白符
end
--
hello = world
from= lua
[Finished in 0.1s]
------
local s = "hello world from lua"
local d = "hello = world, from = lua"
for w in string.gmatch(d, "%a = %a") do
    print(w)
end

--
o = w
m = l
[Finished in 0.1s]
local s = "hello world from lua"
local d = "hello = world, from = lua"
for w in string.gmatch(d, "%a+ = %a+") do
    print(w)
end
---
hello = world
from = lua
[Finished in 0.1s]

table的赋值

local a = {} 
a.b = {}   -- 不能加local，会报错的，否则就相当于有创建了一个新的表，
table.insert(a.b,33) --table中a对应的v为一个数组{33,22,44}
table.insert(a.b,22) 
-- a.m = c 
table.insert(a.b,44) 

for k,v in pairs(a.b) do 
 print(k,v) 
end 

结果：

1   33
2   22
3   44

求一个数组中的值对应的个数

local result = {}

local object = {23,22,33,23,55,66,23} 

for i=1,#object do   -- 因为要返回的result是个空表，让数组object中的值作为一个新表result的k，那么                      相同key对应的v可以汇集起来
    result[object[i]] = (result[object[i]] or 0) + 1   -- 相同的k默认为1，如果相同的key遍历2次就增加一个
end 
print(result[23])
--
结果：3