[reactive] First draft of reactive-tetris

[Peter Verswyvelen]

Just to be curious, what would be the definition of withSubs? Something like
withSubs :: [a] -> Event b -> Event (b,a)
withSubs xs = (fmap.fmap) head . stateE xs tail

Haven't tested it, still actively learning reactive...

2008/11/18 Conal Elliott <conal at conal.net>

> Also, a less forgetful version of subs might be useful:
>
>      withSubs xs e :: [a] -> Event b -> Event (b,a)
>
> and then
>
>     subs xs e  = snd <$> withSubs xs e
>
> or, if you like,
>
>     subs = (fmap.fmap.fmap) snd withSubs
>
> Btw, you can read the three fmaps directly from the signature of withSubs
> (two arrows plus one Event on the way to the pair).
>
>   - Conal
>
>
> On Tue, Nov 18, 2008 at 10:11 AM, Conal Elliott <conal at conal.net> wrote:
>
>> Cool!  Thanks to quicksilver for the insight on and elegant definition of
>> subs.
>>
>> How about one of the following terser variations on the randomEvent def:
>>
>>     randomEvent std e = subs (randoms g) e
>>
>>     randomEvent std = subs (randoms g)
>>
>>     randomEvent = subs . randoms
>>
>>
>>   - Conal
>>
>> 2008/11/18 Creighton Hogg <wchogg at gmail.com>
>>
>>>
>>> Being a dirty schlub & replying to myself, it turns out there is a way to
>>> substitute an infinite list into an Event as we've talked about this on
>>> #haskell this morning.
>>>
>>> subs xs e :: [a] -> Event b -> Event a
>>> subs xs e = head <$> accumE xs (tail <$ e)
>>>
>>> so then we can very easily do
>>>
>>> randomEvent :: (RandomGen g,Random b) => g -> Event a -> Event b
>>> randomEvent std e = let vals = randoms g in subs vals e
>>>
>>> Cool!
>>> Now I just need to change my Tetris to do that instead of messing with a
>>> Behavior.
>>>
>>>
>>>
>>>
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>>>
>>>
>>
>
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