YARD how to document a @param of Array<Array<String>>

Question

Let's say I have the following function:

@param foo [Array<String>]
def recursive_split(foo)
  bar = []
  foo.each do |elem|
    bar.append(elem.split(''))
  end
  bar
end

How do I document with the yard @return tag that my return value is an array of arrays of strings ? Is @return [Array<Array<String>>] the right way to do it ?

Answer 1

The docs aren't that specific but types specifiers are recursive so the X in Array<X> can be any list of valid types so these:

Array<String>
Array<String, Symbol>
Array<Array<String, Symbol, #m>>
Array<String, Array<#m>>
...

are all valid.

The online type parser is probably the easiest way to check. That says that Array<Array<String>> is:

an Array of (an Array of (Strings))