8 Apr
2010
8 Apr
'10
3:38 p.m.
On 04/08/10 13:10, Jonathan Cast wrote:
The equational law relating<$> to<*> for Applicative instances is
f<$> a = return f<*> a
We analogously have
a<$$> f = a<**> return f
as well. So the analogy between<$$> and<**> holds.
This parallelism also suggests to me that <$$> should be placed (only) in Control.Applicative, which is where <*>, <$>, and <**> reside. Yeah, I know that's annoying... -Isaac