我是红宝石的新手,我的哈希数据如下。
person = {
"PoolName.11.22.33":"pool_a",
"PoolMemberName.11.22.33.11":"member_pool_a1",
"PoolMemberScore.11.22.33.11":0,
"PoolName.11.22.44":"pool_b",
"PoolMemberName.11.22.44.11":"member_pool_b1",
"PoolMemberName.11.22.44.12":"member_pool_b2",
"PoolMemberScore.11.22.44.11":2,
"PoolMemberScore.11.22.44.12":3,
"PoolName.11.22.55":"pool_c",
"PoolMemberName.11.22.55.11":"member_pool_c1",
"PolMemberName.11.22.55.12":"member_pool_c2",
"PoolMemberName.11.22.55.13":"member_pool_c3",
"PoolMemberScore.11.22.55.11":11,
"PoolMemberScore.11.22.55.12":22,
"PoolMemberScore.11.22.55.13":33
}
我能否获得如下所示的结果:
"pool_a.member_pool_a1" : 0,
"pool_b.member_pool_b1" : 2,
"pool_b.member_pool_b2" : 3,
"pool_c.member_pool_c1" : 11,
"pool_c.member_pool_c2" : 22,
"pool_c.member_pool_c3" : 33
答案 0 :(得分:1)
person.
slice_before { |_,v| v.is_a?(String) &&
v.match?(/\Apool_\p{Lower}{,2}\z/) }.
each_with_object({}) do |((_, pool), *rest),h|
pool_str = pool + ".member_pool_"
rest.group_by { |k,_| k[/(?:\.\d+)+\z/] }.
each do |_,((_,s),(_,n))|
(s,n = n,s) if n.is_a?(String)
h[(pool_str + s[/[^_]+\z/]).to_sym] = n
end
end
#=> {:"pool_a.member_pool_a1"=>0,
# :"pool_b.member_pool_b1"=>2,
# :"pool_b.member_pool_b2"=>3,
# :"pool_c.member_pool_c1"=>11,
# :"pool_c.member_pool_c2"=>22,
# :"pool_c.member_pool_c3"=>33}
步骤如下 1 。
c = person.slice_before { |_,v| v.is_a?(String) &&
v.match?(/\Apool_\p{Lower}{,2}\z/) }
#=> #<Enumerator: #<Enumerator::Generator:0x00005d500f652950>:each>
我们可以看到此枚举器将其转换为数组所生成的值。
c.to_a
#=> [[[:"PoolName.11.22.33", "pool_a"],
# [:"PoolMemberName.11.22.33.11", "member_pool_a1"],
# [:"PoolMemberScore.11.22.33.11", 0]],
# [[:"PoolName.11.22.44", "pool_b"],
# [:"PoolMemberName.11.22.44.11", "member_pool_b1"],
# [:"PoolMemberName.11.22.44.12", "member_pool_b2"],
# [:"PoolMemberScore.11.22.44.11", 2],
# [:"PoolMemberScore.11.22.44.12", 3]],
# [[:"PoolName.11.22.55", "pool_c"],
# [:"PoolMemberName.11.22.55.11", "member_pool_c1"],
# [:"PolMemberName.11.22.55.12", "member_pool_c2"],
# [:"PoolMemberName.11.22.55.13", "member_pool_c3"],
# [:"PoolMemberScore.11.22.55.11", 11],
# [:"PoolMemberScore.11.22.55.12", 22],
# [:"PoolMemberScore.11.22.55.13", 33]]]
如所见,c
生成3个数组,三个池“ a”,“ b”和“ c”中的每个池一个。参见Enumerable#slice_before。继续
d = c.each_with_object({})
#=> #<Enumerator: #<Enumerator:
# #<Enumerator::Generator:0x00005d500f652950>:each>
# :each_with_object({})>
d
可以被视为复合枚举器,尽管Ruby没有这种概念。参见Enumerable#each_with_object。生成第一个元素并将其传递给块,然后将块变量分配给该值。
((_, pool), *rest),h = d.next
#=> [[[:"PoolName.11.22.33", "pool_a"],
# [:"PoolMemberName.11.22.33.11", "member_pool_a1"],
# [:"PoolMemberScore.11.22.33.11", 0]], {}]
我们看到块变量现在具有以下值。
pool
#=> "pool_a"
rest
#=> [[:"PoolMemberName.11.22.33.11", "member_pool_a1"],
# [:"PoolMemberScore.11.22.33.11", 0]]
h #=> {}
将数组分解成它们感兴趣的部分称为"array decomposition"(搜索“数组分解”)。也称为数组消除歧义。这是一种非常强大且有用的技术。请注意,_
是有效的但有些特殊的局部变量。使用下划线(或以下划线开头的变量名称)的主要原因是告知读者该变量未在后续计算中使用。继续
pool_str = pool + ".member_pool_"
#=> "pool_a.member_pool_"
e = rest.group_by { |k,_| k[/(?:\.\d+)+\z/] }
#=> {".11.22.33.11"=>[
# [:"PoolMemberName.11.22.33.11", "member_pool_a1"],
# [:"PoolMemberScore.11.22.33.11", 0]]}
请参见Enumerable#group_by。继续
g = e.each
#=> #<Enumerator:
# {".11.22.33.11"=>[
# [:"PoolMemberName.11.22.33.11", "member_pool_a1"],
# [:"PoolMemberScore.11.22.33.11", 0]]}:each>
很多枚举符,是吗?再次,生成枚举数的第一个元素并将其传递给块,并为块变量分配值:
p,((q,s),(r,n)) = g.next
#=> [".11.22.33.11",
# [[:"PoolMemberName.11.22.33.11", "member_pool_a1"],
# [:"PoolMemberScore.11.22.33.11", 0]]]
p #=> ".11.22.33.11"
q #=> :"PoolMemberName.11.22.33.11"
s #=> "member_pool_a1"
r #=> :"PoolMemberScore.11.22.33.11"
n #=> 0
p
,q
和r
未在块计算中使用。因此,我对所有这三个变量都使用了_
:
each do |_,((_,s),(_,n))| ...
此数组分解可能看起来极其复杂,但实际上并非如此。只需将上面一行中括号的位置与上面显示的g.next
返回值中括号的位置进行比较即可。
现在执行块计算。我们无法确定g.next
的两个元素的顺序正确(尽管它们在这里),因此如果需要,我们可以将它们反转。
(s,n = n,s) if n.is_a?(String)
#=> nil
s #=> "member_pool_a1"
n #=> 0
i = s[/[^_]+\z/]
#=> "a1"
j = pool_str + i
#=> "pool_a.member_pool_a1"
k = j.to_sym
#=> :"pool_a.member_pool_a1"
h[k] = n
#=> 0
h #=> {:"pool_a.member_pool_a1"=>0}
作为g.size #=> 1
,我们以g
结尾。因此,下一步就是生成d
的下一个元素(池“ b”):
((_, pool), *rest),h = d.next
#=> [[[:"PoolName.11.22.44", "pool_b"],
# [:"PoolMemberName.11.22.44.11", "member_pool_b1"],
# [:"PoolMemberName.11.22.44.12", "member_pool_b2"],
# [:"PoolMemberScore.11.22.44.11", 2],
# [:"PoolMemberScore.11.22.44.12", 3]],
# {:"pool_a.member_pool_a1"=>0}]
pool
#=> "pool_b"
rest
#=> [[:"PoolMemberName.11.22.44.11", "member_pool_b1"],
# [:"PoolMemberName.11.22.44.12", "member_pool_b2"],
# [:"PoolMemberScore.11.22.44.11", 2],
# [:"PoolMemberScore.11.22.44.12", 3]]
h #=> {:"pool_a.member_pool_a1"=>0}
注意如何更新块变量h
。其余计算类似。
1位经验丰富的红宝石:血腥细节警报!