On Sunday, July 8, 2012 12:03:34 AM UTC+2, Charles Oliver Nutter wrote: > > * Exceptions as non-exceptional or moderately-exceptional method results > > In this case I'm specifically thinking about Ruby's tendency to > propagate errno values as exceptions; EAGAIN/EWOULDBLOCK for example > are thrown from nonblocking IO methods when there's no data available. > > You will probably say "that's a horrible use for exceptions" and I > agree. But there are a couple reasons why it's nicer too: > - using return value sigils requires you to propagate them back out > through many levels of calls > - exception-handling is cleaner in code than having all your errno > handling logic spliced into regular program flow > > In any case, the cost of generating a stack trace for potentially > every non-blocking IO call is obviously too high. In JRuby, we default > to having EAGAIN/EWOULDBLOCK exceptions not generate a stack trace, > and you must pass a flag for them to do so. The justification is that > these exceptions are almost always used to branch back to the top of a > nonblocking IO loop, so the backtrace is useless. >
That's also the approach used in Scala for non local returns from closures and breaks [1] [2]. -jason [1] https://github.com/scala/scala/blob/master/src/library/scala/util/control/NoStackTrace.scala [2] https://github.com/scala/scala/blob/master/src/library/scala/util/control/ControlThrowable.scala
_______________________________________________ mlvm-dev mailing list mlvm-dev@openjdk.java.net http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev
