co2

co2 is an extended replacement for the lua (inbuilt) coroutine library. It was conceived mostly because of my constant frustration that coroutine.resume acts like pcall, and not a normal call.

Differences between co2 and coroutine

The functionality provided by co2 differs from the coroutine library in a few significant ways:

• co2.resume propagates errors properly. When an error occurs in a coroutine, coroutine.resume acts like pcall and returns it, co2.resume instead throws a new error in the calling coroutine.
• co2.presume implements the coroutine.resume semantics.
• co2.xpresume is the xpcall version of co2.resume. Call co2.xpresume with a coroutine, a handler, and the arguments to resume the coroutine with. In case of an error, the handler is called with the error message, and the coroutine that errored.
• It comes with an integrated traceback utility co2.traceback. This traceback combines both the traceback of the supplied coroutine, and the calling coroutine. Mostly useful when combined with co2.xpresume.

Using this library

The best way to obtain this library is via luarocks. Alternatively, you can use this library by placing the contents of the src directory in a location on your lua load path.

Once installed, you can require the co2 library as follows:

local co2 = require "co2"

Running the tests

You can run the provided unit tests using the busted test framework. When installed you can run busted tests from the root of this repository.