HONS-CLEAR.html -- ACL2 Version 6.3

## HONS-CLEAR

`(hons-clear gc)` is a drastic garbage collection mechanism that clears out `` the underlying Hons Space.

    Major Section:  HONS-AND-MEMOIZATION

This documentation topic relates to the experimental extension of ACL2 supporting hash cons, fast alists, and memoization; see hons-and-memoization.

Logically, `hons-clear` just returns nil; we leave it enabled and would think it odd to ever prove a theorem about it.

Under the hood, `hons-clear` brutally (1) clears all the tables that govern which conses are normed, then (2) optionally garbage collects, per the `gc` argument, then finally (3) re-norms the keys of `fast-alists` and persistently normed conses; see hons-copy-persistent.

Note. The hash tables making up the Hons Space retain their sizes after being cleared. If you want to shrink them, see `hons-resize`.

Note. CCL users might prefer `hons-wash`, which is relatively efficient and allows for the garbage collection of normed conses without impacting their normed status.

Note. It is not recommended to interrupt this function. Doing so may cause persistently normed conses and fast alist keys to become un-normed, which might lead to less efficient re-norming and/or violations of the fast-alist discipline.