[Haskell-beginners] Type classes and synonyms

Tony Morris tonymorris at gmail.com
Sat Nov 21 18:11:21 EST 2009

If you don't yet understand Arrows, then what compels you to conclude
that there are more idiomatic solutions (than what you don't yet
Just sayin'

Isaac Dupree wrote:
> 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
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Tony Morris

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