This monkey patch function for Hash should be easiest (at least for me). It also doesn't alter structure i.e. changing nil's to {}. It would still also apply even if you're reading a tree from a raw source e.g. JSON. It also doesn't need to produce empty hash objects as it goes or parse a string. rescue nil was actually a good easy solution for me as I'm brave enough for such a low risk but I find it to essentially have a drawback with performance.
class ::Hash
def recurse(*keys)
v = self[keys.shift]
while keys.length > 0
return nil if not v.is_a? Hash
v = v[keys.shift]
end
v
end
end
Example:
> structure = { :a => { :b => 'foo' }}
=> {:a=>{:b=>"foo"}}
> structure.recurse(:a, :b)
=> "foo"
> structure.recurse(:a, :x)
=> nil
What's also good is that you can play around saved arrays with it:
> keys = [:a, :b]
=> [:a, :b]
> structure.recurse(*keys)
=> "foo"
> structure.recurse(*keys, :x1, :x2)
=> nil
