Rolling <anything>

Roll, and then finish the <anything> call. All of the "ing" calls (Flowing, Rolling, etc.) apply some action to the preceding call, and then let that action replace the first part of the "anything" call.

\phfour{b1n,g1s,g2n,b2s} \phBB{g1s,b2n,b1s,g2n} \phBB{g1w,b2e,b1w,g2e} \phfour{g2s,b1n,b2s,g1n}
1 1 2 2 1 2 1 2 1 2 1 2 2 1 2 1
before Recycle before Rolling Contour the Line after Roll finished