class Arel::SelectManager

def collapse(exprs)
  exprs = exprs.compact
  exprs.map! { |expr|
    if String === expr
      # FIXME: Don't do this automatically
      Arel.sql(expr)
    else
      expr
    end
  }
  if exprs.length == 1
    exprs.first
  else
    create_and exprs
  end
end