# \#hashtbl **URL:** https://discuss.ocaml.org/tag/hashtbl/214.md [Latest](https://discuss.ocaml.org/latest.md) · [Categories](https://discuss.ocaml.org/categories.md) · [Tags](https://discuss.ocaml.org/tags.md) --- ## [JaneStreet's OCaml Core library's Hashtbl interfaces](https://discuss.ocaml.org/t/janestreets-ocaml-core-librarys-hashtbl-interfaces/15323)
**Author:** [@s.t.s](https://discuss.ocaml.org/u/s.t.s)\ **Replies:** 16\ **Last updated:** [September 28, 2024, 9:59pm UTC](https://discuss.ocaml.org/t/janestreets-ocaml-core-librarys-hashtbl-interfaces/15323 "2024-09-28T21:59:56Z")
Available Hash Table APIs The question is about which approach to constructing a hash table in Core is preferable. I noticed that the JaneStreet’s Core Hashtbl library provides several interfaces to creating hash table… --- ## [Dump Hashtbl.t to list or assoc list](https://discuss.ocaml.org/t/dump-hashtbl-t-to-list-or-assoc-list/10389)
**Author:** [@olleharstedt](https://discuss.ocaml.org/u/olleharstedt)\ **Replies:** 2\ **Last updated:** [August 29, 2022, 9:33am UTC](https://discuss.ocaml.org/t/dump-hashtbl-t-to-list-or-assoc-list/10389 "2022-08-29T09:33:49Z")
Is there no easy or built-in way to dump all keys and/or values of a hash table to a list or assoc list? Lists are easier to use when asserting equality in tests, like test\_eq. I find iter, but no map, which is weird, o… --- ## [In Core, how does the \`compare\` function (of keys) affect the performance of a hash table?](https://discuss.ocaml.org/t/in-core-how-does-the-compare-function-of-keys-affect-the-performance-of-a-hash-table/5661)
**Author:** [@trungta](https://discuss.ocaml.org/u/trungta)\ **Replies:** 3\ **Last updated:** [May 1, 2020, 4:18pm UTC](https://discuss.ocaml.org/t/in-core-how-does-the-compare-function-of-keys-affect-the-performance-of-a-hash-table/5661 "2020-05-01T16:18:50Z")
Hi, I’m using the module Hashtbl of Core to create a hash table whose key is of the type Llvm.llvalue. Here is the function Hashtbl.create: let create ?growth\_allowed ?size m = create ~hashable:(Hashable.of\_key m) ?g… --- ## [Use Case for Ephemerons?](https://discuss.ocaml.org/t/use-case-for-ephemerons/2838)
**Author:** [@lindig](https://discuss.ocaml.org/u/lindig)\ **Replies:** 4\ **Last updated:** [February 5, 2020, 5:34pm UTC](https://discuss.ocaml.org/t/use-case-for-ephemerons/2838 "2020-02-05T17:34:45Z")
I’d like to understand Ephemerons better. They are designed to implement caches whose values can be collected by the GC when no longer used and have been added to the OCaml standard library. So far, I would use the Weak … --- ## [Hashtbl find\_opt function](https://discuss.ocaml.org/t/hashtbl-find-opt-function/3615)
**Author:** [@cloudyhug](https://discuss.ocaml.org/u/cloudyhug)\ **Replies:** 1\ **Last updated:** [April 2, 2019, 7:04pm UTC](https://discuss.ocaml.org/t/hashtbl-find-opt-function/3615 "2019-04-02T19:04:52Z")
I found this code for the Hashtbl.find\_opt function while looking at the implementation of Hashtbl in the standard library. let rec find\_rec\_opt key = function | Empty -\> None | Cons{key=k; data; next} -\> … --- ## [\[ANN\] dokeysto: a simple key-value store in ocaml](https://discuss.ocaml.org/t/ann-dokeysto-a-simple-key-value-store-in-ocaml/2173)
**Author:** [@UnixJunkie](https://discuss.ocaml.org/u/UnixJunkie)\ **Replies:** 1\ **Last updated:** [June 20, 2018, 1:45am UTC](https://discuss.ocaml.org/t/ann-dokeysto-a-simple-key-value-store-in-ocaml/2173 "2018-06-20T01:45:08Z")
Hello, Dokeysto provides a persistent hash table of string keys to string values. Optionally, if you use the right module (like Dokeysto.Db.RWZ), values will be compressed using LZ4 before being written to disk. The … --- ## [\[ANN\] first release of phashtbl](https://discuss.ocaml.org/t/ann-first-release-of-phashtbl/1965)
**Author:** [@UnixJunkie](https://discuss.ocaml.org/u/UnixJunkie)\ **Replies:** 0\ **Last updated:** [May 8, 2018, 7:46am UTC](https://discuss.ocaml.org/t/ann-first-release-of-phashtbl/1965 "2018-05-08T07:46:03Z")
Hi all, Phashtbl is a minimalist persistent hashtbl OCaml library. It was just accepted into the opam-repository. Code: Interface: Example/tests: Enjoy! :blush: