In this chapter, we reviewed the data structure of Queue with a custom functional implementation. We introduced the FSharpX open source collection of functional data structures. Finally, we explored the F# agent implementation of MailboxProcessor, and provided an example use of queue for creating async work flows, throttling, and post-processing.

In the next chapter, Quick Boost with Graph, we will briefly discuss how a graph can be functionally implemented in F#, and review the challenges associated with this task. Then we will present how to utilize QuickGraph (a standard graph library in .NET) for our purposes, explaining where to find commonly used graph implementations and discussing one of the most commonly used algorithms: Dijkstra's shortest part algorithm.