ruby - 从几个哈希生成每个组合

Question

我有几个数组，我就说四个。例如:

LOCATION  = [:new_york, :california, :alaska, :missouri, :mississippi, :florida]
TYPE      = [:high_rise, :mid_rise, :low_rise, :loft, :townhouse, :hotel]
OWNERSHIP = [:coop, :condo, :condop, :rental, :single_family, :multi_family]
BLDG_AGE  = [:historic, :pre-war, :post-war, :modern]

我需要一个脚本来生成这些的每一个组合。以下是一些示例:

:new_york
:new_york, :high_rise
:new_york, :high_rise, :coop
:new_york, :high_rise, :coop, :historic

这些都是简单的，只是一堆嵌套循环。我还需要其他组合。例如:

:new_york, :coop
:new_york, :pre-war
:new_york, :rental, :modern
:new_york, :high_rise, :single_family

但是想想每个组合，只有 LOCATION 的成员可以单独出现。

Answer 1

假设您想要 :pre_war, :post_war 而不是 :pre-war, :post-war :

LOCATION  = [:new_york, :california, :alaska, :missouri, :mississippi, :florida]
TYPE      = [:high_rise, :mid_rise, :low_rise, :loft, :townhouse, :hotel]
OWNERSHIP = [:coop, :condo, :condop, :rental, :single_family, :multi_family]
BLDG_AGE  = [:historic, :pre_war, :post_war, :modern]

LOCATION.product([nil] + TYPE, [nil] + OWNERSHIP, [nil] + BLDG_AGE)
.map(&:compact)

或更简洁:

LOCATION.product(*[TYPE, OWNERSHIP, BLDG_AGE].map{|a| [nil] + a})
.map(&:compact)