Philip Scott wrote:
Thanks John,
Every module can have its own definition for each name, such as the operator (+). So in your module (eg. module Main, or module DateValueSeries), you can go ahead and define your own (+). The major caveat is making sure you don't conflict with the default (+), which lives in module Prelude, which is normally automatically brought into scope.
That actually quite nicely solves the problem... it feels almost a little too easy, after spending the evening getting my mind wrapped up with Arrows :)
why has no one mentioned: you most likely don't need to understand Arrows? I'm pretty good with Haskell, and Arrows are still somewhat confusing to me. Why? Most problems I've worked with in Haskell have had more-idiomatic solutions than Arrows. (examples include: Monad; Functor; Applicative; just plain functions; plain old lack of type-class abstraction.) It's not so easy or useful to understand any abstraction/class without using at least two or three useful examples/instances of it first. -Isaac