WList is a simple word-list generator. It’s probably not what you came here for, but some name parts are best filled with a word-list. It supports weighted words, so that you can make common words appear more often.
A WorkingSet is a crucial part of this generator’s performance. It is all local state required to generate a name and get the output without performing additional allocations per generation once the WorkingSet’s underlying vectors have grown.
Format string. This does two allocations.