On Mon, Oct 31, 2011 at 3:19 PM, John Lask jvl...@hotmail.com wrote:
On 1/11/2011 1:35 AM, Captain Freako wrote:
you need to study ArrowLoop and understand that.
Thanks, John.
I'm working my way through Hughes' suggested exercise in `Programming
with Arrows', to wit:
The reader who finds
Hi John,
I'm trying to use the GHCI debugger on this code:
20 instance ArrowLoop SF where
21 loop (SF f) = SF $ \as -
22 let (bs, cs) = unzip (f (zip as (stream cs))) in bs
23 where stream ~(x:xs) = x : stream xs
24
25 swap :: (a,b) - (b,a)
26 swap (x,y) = (y,x)
in
Try
swap p = (snd p, fst p)
or, equivalently
swap ~(x,y) = (y,x)
-- ryan
On Tue, Nov 1, 2011 at 1:30 PM, Captain Freako capn.fre...@gmail.comwrote:
Hi John,
I'm trying to use the GHCI debugger on this code:
20 instance ArrowLoop SF where
21 loop (SF f) = SF $ \as -
22
Never mind, I misread the code, 'zip' and the lazy definition of stream
should add the necessary laziness.
-- ryan
On Tue, Nov 1, 2011 at 3:36 PM, Ryan Ingram ryani.s...@gmail.com wrote:
Try
swap p = (snd p, fst p)
or, equivalently
swap ~(x,y) = (y,x)
-- ryan
On Tue, Nov 1, 2011
I can't comment on using ghci debugger to observe evaluation. I have in
the past used hood (http://hackage.haskell.org/package/hood) and found
it both convenient and useful when trying to observe evaluation order.
On 2/11/2011 7:00 AM, Captain Freako wrote:
Hi John,
I'm trying to use the
First, let's lay out our definitions:
unzip [] = ([], [])
unzip ((x,y):xys) = (x:xs, y:ys) where (xs,ys) = unzip xys
zip [] _ = []
zip _ [] = []
zip (x:xs) (y:ys) = (x,y) : zip xs ys
map _ [] = []
map f (x:xs) = f x : map f xs
stream ~(a:as) = a : stream as
-- equivalently
stream xs = head xs
Hi John,
Thanks for all your help.
I've been studying your suggested code:
type FilterAu b c = Automaton (-) b c
liftAu :: ((x,FilterState s)-(y,FilterState s)) - FilterState s -
FilterAu x y
liftAu f s0 = proc x - do
rec (y,s') - arr f - (x,s)
s - delay s0 - s'
returnA
On 1/11/2011 1:35 AM, Captain Freako wrote:
you need to study ArrowLoop and understand that. In the code
rec (y,s')- arr f - (x,s)
s- delay s0 - s'
the state is 'captured' in the recursive binding. i.e. just like in real
circuits the output state s is threaded back as an input.
The
