mutable struct DrunkardsState <: State loc::Int steps::Int wallsLoc::Int end DrunkardsState(sim::DrunkardsWalkSim) = DrunkardsState(start(sim), 0, walls(sim)) const DWState = DrunkardsState location(state::DWState) = state.loc steps(state::DWState) = state.steps walls(state::DWState) = state.wallsLoc closestwall(state::DWState) = (location(state) < 0 ? :left : location(state) > 0 ? :right : :neither )