Routes :requirments

I want to set a route :requirements on an array that verifies a
particular parameter is included in an array.

Something to the effect of:

atypes = [:culture, :personality, :communication]
map.with_options(:path_prefix => ':atype',
  :requirements => {:atype => atypes.include?(:atype)}) do |assessment|

I haven't been able to find any documentation on how to accomplish this.
Any help would be appreciated.

:requirements => {:atype => /culture|personality|communication/}

I believe the right hand side of any requirement has to be a regexp...