kind of got it now

[juan_gandhi]

Until I was told to take a look at coalgebras, and figured out that input deals with codata, and output deals with data, and that StringReader consists of mapping an algebra to a coalgebra, over the same affine functor, X -> AX + 1, I could not figure out how to properly connect my binary files with parser combinators... and the whole functioning of parser combinators in general.

The main point is that parser combinators work not on data, but on codata. So there.

Comments

[ivan-gandhi.livejournal.com]

Except that, with such a vague definition, algebras will almost fit as well. But strictly speaking, yes, it is a coalgebra.