Question on `runState'

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Question on `runState'

David Banas-2

In this excerpt from the `StateArrow' page:

runState :: Arrow a => StateArrow s a e b -> a (e, s) (b, s)Source

what's the significance of having written "StateArrow s a e b", instead of "StateArrow s a b c"?


Thanks,

-db



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Re: Question on `runState'

Conrad Parker
On 17 October 2011 23:59, Captain Freako <[hidden email]> wrote:
> In this excerpt from the `StateArrow' page:
>
> runState :: Arrow a => StateArrow s a e b -> a (e, s) (b, s)Source
>
> what's the significance of having written "StateArrow s a e b", instead of
> "StateArrow s a b c"?

In the context of that page, do you think e might stand for something?

btw. what's the URL?

Conrad.

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Re: Question on `runState'

David Fox-7
On Mon, Oct 17, 2011 at 5:32 PM, Conrad Parker <[hidden email]> wrote:

> On 17 October 2011 23:59, Captain Freako <[hidden email]> wrote:
>> In this excerpt from the `StateArrow' page:
>>
>> runState :: Arrow a => StateArrow s a e b -> a (e, s) (b, s)Source
>>
>> what's the significance of having written "StateArrow s a e b", instead of
>> "StateArrow s a b c"?
>
> In the context of that page, do you think e might stand for something?
>
> btw. what's the URL?

http://hackage.haskell.org/packages/archive/arrows/0.4.1.2/doc/html/Control-Arrow-Transformer-State.html

I think maybe b is for beginning and e is for end?

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