[Haskell-cafe] Re: Re[2]: Why monad tutorials don't work

[Dan Piponi]

On 8/15/07, Andy Gimblett <A.M.Gimblett at swansea.ac.uk> wrote:
> I assumed he was just trying not to sing the "Spider Pig" song.

I've been banned from singing that around the house. And the cat version.

But I was mainly thinking about how the physicist's definition of
tensor needn't be accepted as an irreducible given, but is a
consequence of the definition of tensor product through its universal
property: http://planetmath.org/encyclopedia/TensorProduct.html

Having said that, I still completely agree with Michael that tensors
are a great analogy for monads because I found the concept of a
universal property tricky in the same way that I subsequently found
monads tricky. BTW I think the concept of a universal property is
probably the single most useful idea from category theory that can be
used in Haskell programming. I recommend it to everyone :-)
--
Dan