Send Beginners mailing list submissions to
[email protected]
To subscribe or unsubscribe via the World Wide Web, visit
http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
or, via email, send a message with subject or body 'help' to
[email protected]
You can reach the person managing the list at
[email protected]
When replying, please edit your Subject line so it is more specific
than "Re: Contents of Beginners digest..."
Today's Topics:
1. arrows and 2-tuples (Dennis Raddle)
----------------------------------------------------------------------
Message: 1
Date: Tue, 16 Feb 2016 00:06:21 -0800
From: Dennis Raddle <[email protected]>
To: Haskell Beginners <[email protected]>
Subject: [Haskell-beginners] arrows and 2-tuples
Message-ID:
<CAKxLvoo=656XCBCaW-SRys6rJ1dB=axypcxqjfpyrrvp3b_...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
I am a Haskell beginner. I have used arrows occasionally to move 2-tuples
around, but don't understand more than that.
I'm interested in know what's the connection between arrows and 2-tuples. I
don't really understand most of the Control.Arrow docs, but it seems that a
lot of stuff about arrows doesn't mention 2-tuples. Yet the operators
(***), (&&&), first, and second seem to be common. Is there some way to
explain the link?
Also, the main instance of Arrow seems to be (->). There is also something
about Kleisli monads, but I don't know what those are. Is there an another
big use case for arrows besides (->)? Don't worry about explaining it all,
just a quick mention would be fine and I can investigate it myself.
D
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://mail.haskell.org/pipermail/beginners/attachments/20160216/84755a75/attachment-0001.html>
------------------------------
Subject: Digest Footer
_______________________________________________
Beginners mailing list
[email protected]
http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
------------------------------
End of Beginners Digest, Vol 92, Issue 18
*****************************************
