title: Haskell: TVar: orElse
body: <p>Is the "else" part of <a href="http://www.haskell.org/ghc/docs/6.12.1/html/libraries/base/GHC-Conc.html#v%3aorElse"><code>orElse</code></a> called when a transaction is retried due to another transaction writing to a <code>TVar</code> it had read, or only when <a href="http://www.haskell.org/ghc/docs/6.12.1/html/libraries/base/GHC-Conc.html#v%3aretry"><code>retry</code></a> is explicitly called?</p>