Some notes on endianness

What is the right way to understand endianness?

In my view endianness makes much more sense when viewed as a matter of bit order: these notes explore how byte order and byte swapping are a consequence of bitwise endianness combined with bytewise addressing and data transmission. But byte swapping isn't the only flavour of endianness: bitwise endianness is equally comfortable with oddities like PDP11 word swapping.

I also explain why big-endian is just as mathematically elegant as little-endian: they are perfectly dual to each other, so one can't be more elegant than the other.

There's a sketch of an abstract API for endian-aware bit sequences, designed with algebra in mind (associativity, anamorphisms and catamorphisms).

edited to add: this article has a sequel with improved symmetry

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