Wouldn't be nice to have such function?
I wanted to translate a thread example written in Ruby and realized
that it's impossible to write that function using MVar primitives
provided; and no module seems to provide an equivalent using
another kind of concurrent variable. I had to simulate mutexes with
MVar (Maybe [MVar ()]) instead of MVar (). I guess that this function
should be possible to implement on plain MVars.
The semantics is obvious: if the variable is empty, return Nothing,
else take its value and return Just it.
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__("< Marcin Kowalczyk * [EMAIL PROTECTED] http://qrczak.ids.net.pl/
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QRCZAK 5? X- R tv-- b+>++ DI D- G+ e>++++ h! r--%>++ y-
