Lua 5.3 迭代器的简单示例

创建”closure”模式的”iterator”

function allowrds()

    local line = io.read()

    local pos =

    return function ()

        while line do

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

            if s then

                pos = e +

                return string.sub(line, s, e)

            else

                line = io.read()

                pos =

            end

        end

        return nil

    end

end

for word in allowrds() do

    print(word)

end

结果运行现象：

创建”complex state iterator”模式的”iterator”

function iter(state)

    while state.line do

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

        if s then

            state.pos = e +

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

        else

            state.line = io.read()

            state.pos =

        end

    end

    return nil

end

function allowrds()

    local state = {line = io.read(), pos = }

    return iter, state

end

for word in allowrds() do

    print(word)

end

结果运行现象：