Iterate over a deeply nested level of hashes in Ruby
If I understand the goal, then you should be able to pass in the parent to your save method. For the top level, it will be nil. The following shows the idea where puts
is used as a place holder for the "save".
def save_pair(parent, myHash)
myHash.each {|key, value|
value.is_a?(Hash) ? save_pair(key, value) :
puts("parent=#{parent.nil? ? 'none':parent}, (#{key}, #{value})")
}
end
Here is an example call to it:
hash = Hash.new
hash["key1"] = "value1"
hash["key2"] = "value2"
hash["key3"] = Hash.new
hash["key3"]["key4"] = "value4"
hash["key3"]["key5"] = "value5"
hash["key6"] = Hash.new
hash["key6"]["key7"] = "value7"
hash["key6"]["key8"] = Hash.new
hash["key6"]["key8"]["key9"] = "value9"
save_pair(nil, hash)
I know this is a late reply, but I just implemented a non-recursive solution to your problem and thought it is worth sharing.
class Hash
def deep_traverse(&block)
stack = self.map{ |k,v| [ [k], v ] }
while not stack.empty?
key, value = stack.pop
yield(key, value)
if value.is_a? Hash
value.each{ |k,v| stack.push [ key.dup << k, v ] }
end
end
end
end
Then, coming back to your original problem, you can do:
h = {
:key1 => 'value1',
:key2 => 'value2',
:key3 => {
:key4 => 'value4',
:key5 => 'value5'
},
:key6 => {
:key7 => 'value7',
:key8 => {
:key9 => 'value9'
}
}
}
h.deep_traverse{ |path,value| p [ path, value ] }
# => [[:key6], {:key7=>"value7", :key8=>{:key9=>"value9"}}]
# [[:key6, :key8], {:key9=>"value9"}]
# [[:key6, :key8, :key9], "value9"]
# [[:key6, :key7], "value7"]
# [[:key3], {:key4=>"value4", :key5=>"value5"}]
# [[:key3, :key5], "value5"]
# [[:key3, :key4], "value4"]
# [[:key2], "value2"]
# [[:key1], "value1"]
There is also a gist version.