Re: [Haskell-cafe] does try force evaluation of IO value

No, it won't force the return value. To do that, use evaluate http://hackage.haskell.org/packages/archive/base/latest/doc/html/Control-Exc eption-Base.html#g:7 But what is happening when exception is raised when consuming value from result of "try" ? try has signature try :: Exception e => IO a -> IO (Either e a) so it must return either exception value either evaluated value and must not raise exceptions, but how can "try" return (Right a) wthout making sure that action will not raise any exception ?