At 14:05 02/08/04 -0700, John Meacham wrote:
You might be interested in my BooleanAlgebra class, which replaces the
various boolean operators from the prelude with overloaded versions
with various useful instances.
The really nice thing is the instance for Bool is exactly the same as
the prelude ve
On Mon, Aug 02, 2004 at 10:54:33PM +0200, [EMAIL PROTECTED] wrote:
> The operators can be also defined as follows:
>(.&.) f g x = (f x) && (g x)
>(.|.) f g x = (f x) || (g x)
>
> It is clear from these definitions, that the operators are ternary
> operators.
>
> As operators are essential
On Wed, Jul 07, 2004 at 01:18:54PM +0100, Graham Klyne wrote:
There's a pattern of higher-order function usage I find myself repeatedly
wanting to use, exemplified by the following:
[[
-- combineTest :: (Bool->Bool->Bool) -> (a->Bool) -> (a->Bool) ->
(a->Bool)
combineTest :: (b->c->d) -> (a->b)
On Thu, Jul 08, 2004 at 08:36:57PM -0400, David Menendez wrote:
> Conor T McBride writes:
> >
> >infixl 9 <%> -- my name for <# -- others have other names
> >class Idiom i where
> > idi :: x -> i x
> > (<%>) :: i (s -> t) -> i s -> i t
> >
> > I call them idioms because it's li
At 14:45 07/07/04 -0400, Andrew Pimlott wrote:
This can be seen as liftM2 on the reader monad ((->) r):
(.&.) = liftM2 (&&)
Thanks to those who pointed out this.
I think the ((->) r) reader monad is one of those I've yet to fully grasp.
#g
--
At 14:45 07/07/04 -0400, Andrew Pimlott wrote:
> -- comb
Conor T McBride writes:
> As some of you know, I like them a lot too. In fact, if you have a
> return-like thing and an ap-like thing, you can make fmap as well.
> (Note that the return for the environment monad is none other than
> S's best friend K.)
>
> So I got hacking, a little while ago...
On Thu, Jul 08, 2004 at 03:47:08PM +1000, Bernard James POPE wrote:
> I use almost exactly the same thing in my code. And I nearly came
> up with the same names as you! (I have .&&. and .||.)
>
> I find them very useful in guards:
>
>foo x y
> | (this .&&. that) x = ...
>
> I don't beli
Hi folks
Iavor S. Diatchki wrote:
hi,
you can use the reader (environment monad) for this.
lately i have been using 2 combinators to do things like that (thanks to
Thomas Hallgren for showing me this):
-- a nicer name for fmap (or liftM if one prefers)
(#) :: Functor f => (a -> b) -> f a -> f b
On Wed, Jul 07, 2004 at 01:18:54PM +0100, Graham Klyne wrote:
> There's a pattern of higher-order function usage I find myself repeatedly
> wanting to use, exemplified by the following:
>
> [[
> -- combineTest :: (Bool->Bool->Bool) -> (a->Bool) -> (a->Bool) -> (a->Bool)
> combineTest :: (b->c->d)
hi,
you can use the reader (environment monad) for this.
combineTest c t1 t2 = liftM2 c t1 t2
lately i have been using 2 combinators to do things like that (thanks to
Thomas Hallgren for showing me this):
-- a nicer name for fmap (or liftM if one prefers)
(#) :: Functor f => (a -> b) -> f a ->
On Wed, Jul 07, 2004 at 01:18:54PM +0100, Graham Klyne wrote:
> There's a pattern of higher-order function usage I find myself repeatedly
> wanting to use, exemplified by the following:
>
> [[
> -- combineTest :: (Bool->Bool->Bool) -> (a->Bool) -> (a->Bool) -> (a->Bool)
> combineTest :: (b->c->d)
There's a pattern of higher-order function usage I find myself repeatedly
wanting to use, exemplified by the following:
[[
-- combineTest :: (Bool->Bool->Bool) -> (a->Bool) -> (a->Bool) -> (a->Bool)
combineTest :: (b->c->d) -> (a->b) -> (a->c) -> a -> d
combineTest c t1 t2 = \a -> c (t1 a) (t2 a)
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