Functional Pearl: F for Functor
Ralf Hinze, Jennifer Hackett and Daniel W. H. James
Submitted to the International Conference on Functional Programming, Sept. 10–12, 2012, Copenhagen, Denmark.
Teacher: Last week I held a tutorial series with my students on the concept of a functor, with the purpose of taking a fresh look from a few angles they hadn’t considered before.
Lisa: We started gently, but soon built up a heady tower of abstrac­tion, freely wielding the force of functoriality.
Harry: For a newcomer to category theory, I can’t believe how much I learnt. And we were having so much fun, we even continued on into the weekend!
Teacher: Yes, to finish off our week we looked at how we might describe the printf function in terms of monoidal functors.
functor, opposite category, product category, functor category, printf, monoidal category, monoidal functor