How to use ngx.OK ngx.DONE ngx.AGAIN ngx.ERROR ?

[wendal]

In "Nginx API for Lua" -- "Core constants", there are 4 constants .
But there are no any infomation ahout how to use them.

So, how to use them ? Are they as same as NGX_OK/NGX_AGAIN/NGX_DONE/NGX_ERROR ??

[agentzh]

They take the same values of NGX_OK, NGX_AGAIN, NGX_DONE, and NGX_ERROR. But now only ngx.exit() only take two of these values, i.e., NGX_OK and NGX_ERROR. I'll add a quick note to README. Thanks for reminding us.