Parse, don't validate

Easing back into it.

A few observations about completing the challenges.

Unfolding a simulation

Nondeterminism, list monads, and dodgy heuristics

A lot of work to capture features of the problem

Reading around the subject pays dividends

More multisets and debugging

Data.Ix and the first use of the RWS monad

Monoids of endomorphisms

Zippers on trees

A very declarative solution

Monads and bit-fiddling

Monads, typeclasses, and lenses return

MultiSet: Mostly useful.

Why did I overload lists by default?

Complicated rules leads to complicated code

A stack-based parser that does just enough

Revelations of the Ix datatype

Brute force trumps cleverness

Gradient descent and higher-order functions

It's all about the data structures