On Thu, Feb 01, 2007 at 09:12:02AM -0800, David Roundy wrote:
> On Wed, Jan 31, 2007 at 09:28:30PM +0300, Bulat Ziganshin wrote:
> > Next, i don't think that ability to use any functions in view buy
> > something important. pattern guards can be used for arbitrary
> > functions, or such function ca
for (Coord x y) where y>0
> (Polar (-y) (-pi/2))for (Coord x y) where y<0
>
> of course, my syntax is cumbersome. that is important is that view
> definition should be explicit (no arbitrary functions), it should
> mention all possible altern
Hello Arie,
Thursday, February 1, 2007, 2:08:33 PM, you wrote:
> The ability to reason about your program is vital in about every part of
> the programming cycle, and is one of the things that make Haskell work.
when i say what i don't use reasoning, you can trust me :)
> Another of those thing
Bulat Ziganshin wrote:
> ok, i can live without it. i mean reasoning :)
>
> i guess that anything more complex than Turing machine makes reasoning
> harder. 18 years ago Haskell fathers chosen to simpilfy language in
> order to make reasoning easier. may be now we can change this
> decision? that
Hello J.,
Thursday, February 1, 2007, 1:36:33 AM, you wrote:
> Yes - you've reiterated Wadler's original design, with an automatic
> problems with equational reasoning raised by this approach.
ok, i can live without it. i mean reasoning :)
i guess that anything more complex than Turing machine
On 1/31/07, Bulat Ziganshin <[EMAIL PROTECTED]> wrote:
i hope that now my idea is clear
Yes - you've reiterated Wadler's original design, with an automatic
creation of a type class. Erwig and Peyton-Jones, _Pattern Guards and
Transformational Patterns_
(http://research.microsoft.com/~simonpj/
rd x y) where y<0
of course, my syntax is cumbersome. that is important is that view
definition should be explicit (no arbitrary functions), it should
mention all possible alternatives and provide a way to use the same
constructor name both for construction of new values and matching
existing on
On Wed, Jan 31, 2007 at 05:53:08PM +0300, Bulat Ziganshin wrote:
> something like this:
>
> data Coord = Coord Float Float
> view of Coord = Polar Float Float where
> Polar r d= Coord (r*d) (r+d)-- construction
> Coord x y | x/=0 || y/=0 = Polar (x*y) (x+y)-
Hello Simon,
Monday, January 22, 2007, 5:57:27 PM, you wrote:
> adding "view patterns" to Haskell.
many of us was attracted to Haskell because it has clear and simple
syntax. but many Hugs/GHC extensions done by independent developers
differ in the syntax they used, because these developers eith
