Re: [Haskell-cafe] is the evaluation order deterministic when using applicative with IO

On Fri, Mar 16, 2012 at 12:30:13PM +0100, Twan van Laarhoven wrote:

If you want to avoid the side effects of boolTest2 when boolTest1 returns true, you will need to implement a monadic or, something like

orM ma mb = do a <- ma if a then return True else mb

Note also that it is *not possible* to have this short-circuiting behavior using only Applicative. The structure of an Applicative computation is always fixed up front, and cannot depend on intermediate values. -Brent