Get all leaves of a Hash (like recursive values).
Usage
{:x => 1, :y => {:z => 2}}.leaves == [1,2]
Code
class Hash
# {'x'=>{'y'=>{'z'=>1,'a'=>2}}}.leaves == [1,2]
def leaves
leaves = []
each_value do |value|
value.is_a?(Hash) ? value.leaves.each{|l| leaves << l } : leaves << value
end
leaves
end
end
Michael Grosser, the Blog 
I have several remarks regarding the code.
1. The commented out line has a typo (there are 3 opening braces and only 2 closing).
2. It’s better to use “leaves” instead of “leafs”.
3. `each do |key,value|` block don’t use `key` at all. Replace it with `each_value do |value|`
4. `value.respond_to?(:leaves)` looks more natural and idiomatic than `value.is_a?(Hash)`.
5. The whole method actually is an incarnation of `Enumerable#flat_map`. So it would be much shorter to rewrite it. See my final version:
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leaves.rb
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1: duh
2: we had leaves at the start and someone said “lets look into the dictionary…” but google confirms leaves is the better choise 🙂
3: yep, should a bit be faster :>
4: seems about right
5: is only 1.9, so ill keep the original concat
Thanks for the help!
Implementation that retrieves leaf values from a hash of both hashes and arrays:
def leaves(collection)
leaves = []
if collection.is_a?(Hash)
collection.each_value { |l| leaves << leaves(l) }
elsif collection.is_a?(Array)
collection.each { |l| leaves << leaves(l) }
else
leaves << collection
end
leaves.flatten
end