Guide on performance, caching, memoization, etc.

[milesfrain]

Is there any PS content similar to these F# guides?:

• https://en.wikibooks.org/wiki/F_Sharp_Programming/Caching
• https://wj32.org/wp/2016/01/13/f-code-memoize-a-recursive-function/

If a guide is written, should it live in this docs repo, or another location, such as the Mutable State section of the book?

Topics may include:

• How to use:
  • ST
  • Ref
  • memoize
• Interactions with:
  • Recursive functions
  • Parallel code
  • Effectful code
    • e.g. Why can't I use memoize with an effectful function, and what should I do instead?