Lua chapter 6

一个简单的迭代器示例

--迭代工厂函数

function value(t)

local i = 0;

return

function()

i = i+1;

return t[i];

end;

end;

t = {10,20,30};

iter = value(t);

while true do

local element = iter();

if element == nil  then

break;

end;

print("Element: " .. element);

end;

print();

--  另一种写法

for element in value(t) do

print("Element: " .. element);

end;

2、输出所有单词

function allword()

local line = io.read();

local pos = 1;

return

function()

local s, e = string.find(line, "%w+", pos);

if s then

pos = e + 1;

return string.sub(line, s, e);

end;

end;

end;

for word in allword() do

print(word);

end;

Lua chapter 6