Look on hackage at any revision of monoids before 0.2.0, and it will contain Data.Monoid.Lexical.SourcePosition — I recently slimmed the package down and plan to move the remaining functionality into a monoid-extras style package so that the core functionality is available without a laundry list of dependencies.

Your kind error comes from the fact that when I added Pos, I added an argument to the type to make it a Pointed Functor. So you need to make Monoid (SourcePosition f) and Reducer Char (SourcePosition f).

I explained the extra argument as part of the narrative during the talk, but naked slides do not provide me such opportunity for elaboration. :)

`Reducer SourcePosition’ is not applied to enough type arguments
Expected kind `*’, but `Reducer SourcePosition’ has kind `* -> *’
In the instance declaration for `Reducer SourcePosition’

Re: the gravatar thing, hrmm. It is funny that they should be case insensitive given that at least the portion before the @ should technically be handled case sensitively per RFC 2821 (though requiring this is explicitly called out as not being nice in the RFC).

The wordpress gravatar php function seems to be implemented along the guidelines of the other examples on gravatar which only trim whitespace and don’t change case. (i.e. http://en.gravatar.com/site/implement/textpattern)

So I’m thinking that the only way to portably get your gravatar to work on everyone’s site is to explicitly lowercase it yourself since anyone else doing it could incorrectly mangle an email address. ;)

I’d not be adverse to fixing it, since after all case sensitive email addresses don’t seem to really exist in practice, but currently the fragment looks like < ?php gravatar("R", 40); ?> and calls off to some method in some library somewhere, which already knows the email address in question. If I ever learned php, I might know where to find it. :)

[Edit: I did at least tweak your email address to be lowercase. ;) ]

Also, Gravatars don’t seem to work on this blog when using capital letters in the email address.

@wwkeyboard: It should be around the week of the 17th. Ravi was waiting to see what Norman Ramsey’s schedule was like before setting it in stone since we keep scheduling it when he can’t show up!

http://www.mediafire.com/file/anifmxlzfgm/AllAboutMonoids.pdf

If you have Powerpoint 2003, try http://www.microsoft.com/downloads/details.aspx?FamilyId=941b3470-3ae9-4aee-8f43-c6bb74cd1466&displaylang=en.