NB. The stack and queue print object

print_z_ =: monad define
'method value' =. 2 {. y.
if. method -: 'type'
    do. 'print'
  elseif. method -: 'print'
    do.
    while. 0 < # value
      do. for_effect_only display > {. value
          value =. }. value
    end.
  elseif. 1
    do. #. method ; value
end.
)