TUPLE: ship pos dir ; : ( -- ship ) { 0 0 } { 1 0 } \ ship boa ; : move ( ship len dir -- ) n*v [ v+ ] curry change-pos drop ; : rotate ( ship degrees -- ) [ dup dir>> ] dip { { 90 [ [ second ] [ first neg ] bi 2array ] } { 180 [ [ neg ] map ] } { 270 [ [ second neg ] [ first ] bi 2array ] } } case >>dir drop ; : forward ( ship n -- ) over dir>> move ; : sail ( line ship -- ) swap unclip [ string>number ] dip { { CHAR: N [ { 0 +1 } move ] } { CHAR: S [ { 0 -1 } move ] } { CHAR: E [ { +1 0 } move ] } { CHAR: W [ { -1 0 } move ] } { CHAR: L [ 360 swap - rotate ] } { CHAR: R [ rotate ] } { CHAR: F [ forward ] } } case ; "/tmp/input" ascii file-lines [ [ sail ] curry each ] keep pos>> l1-norm