From ComputerCraft Wiki
|Pauses the currently executing coroutine and passes control to its parent. The parent is the coroutine that started this coroutine by calling coroutine.resume on it. The parent regains control by coroutine.resume returning; the child becomes suspended (and can therefore be resumed by coroutine.resume). If parameters var1, var2, etc. are passed, those values appear in the return value from coroutine.resume in the parent. If the call to coroutine.resume that next resumes the child coroutine has parameters, those parameters are returned from the call to this function.|
|Syntax||coroutine.yield([var1], [var2], …)|
|Returns||[var3], [var4], …|
Please see Coroutine (API) for a worked example of using all the coroutine functions.