hamt VS clojure

This isn't a very good explanation. The wikipedia article isn't great either. I like this description:

https://github.com/mkirchner/hamt#persistent-hash-array-mapp...

The name does tell you quite a bit about what these are:

* Hash - rather than directly using the keys to navigate the structure, the keys are hashed, and the hashes are used for navigation. This turns potentially long, poorly-distributed keys into short, well-distributed keys. However, that does mean you have to compute a hash on every access, and have to deal with hash collisions. The mkirchner implementation above calls collisions "hash exhaustion", and deals with them using some generational hashing scheme. I think i'd fall back to collision lists until that was conclusively proven to be too slow.

* Trie - the tree is navigated by indexing nodes using chunks of the (hash of the) key, rather than comparing the keys in the node

* Array mapped - sparse nodes are compressed, using a bitmap to indicate which logical slots are occupied, and then only storing those. The bitmaps live in the parent node, rather than the node itself, i think? Presumably helps with fetching.

A HAMT contains a lot of small nodes. If every entry is a bitmap plus a pointer, then it's two words, and if we use five-bit chunks, then each node can be up to 32 entries, but i would imagine the majority are small, so a typical node might be 64 bytes. I worry that doing a malloc for each one would end up with a lot of overhead. Are HAMTs often implemented with some more custom memory management? Can you allocate a big block and then carve it up?

Could you do a slightly relaxed HAMT where nodes are not always fully compact, but sized to the smallest suitable power of two entries? That might let you use some sort of buddy allocation scheme. It would also let you insert and delete without having to reallocate the node. Although i suppose you can already do that by mapping a few empty slots.

This article will explain how to write a simple service in Clojure. The sweet spot of making applications in Clojure is that you can expressively use an entire rich Java ecosystem. Less code, less boilerplate: it is possible to achieve more with less. In this example, I use most of the libraries from the Java world; everything else is a thin Clojure wrapper around Java libraries.

5. Clojure - $96,381

I have a tangential question that is related to this cool new feature.

Warning: the question I ask comes from a part of my brain that is currently melted due to heavy thinking.

Context: I write a fair amount of Clojure, and in Lisps the code itself is a tree. Just like this F# parallel graph type-checker. In Lisps, one would use Macros to perform compile-time computation to accomplish something like this, I think.

More context: Idris2 allows for first class type-driven development, where the types are passed around and used to formally specify program behavior, even down to the value of a particular definition.

Given that this F# feature enables parallel analysis, wouldn't it make sense to do all of our development in a Lisp-like Trie structure where the types are simply part of the program itself, like in Idris2?

Also related, is this similar to how HVM works with their "Interaction nets"?

https://github.com/HigherOrderCO/HVM

https://www.idris-lang.org/

https://clojure.org/

I'm afraid I don't even understand what the difference between code, data, and types are anymore... it used to make sense, but these new languages have dissolved those boundaries in my mind, and I am not sure how to build it back up again.

As an analogy - my face hasn't changed all that much in a past few years, and I haven't changed my profile picture in those few years. Does it really mean that I'm unmaintained/dead?

> Where can I find latest documentation [...]?

The answer is still https://clojure.org/. And https://clojuredocs.org/ but it's community-maintained so might occasionally be missing some things right after they're released. E.g. as of this moment Clojure 1.11 is still not there since the maintainer of the website has some technical issues deploying the updated version of the website.

For me personally, the best API-level documentation is the source code.

> Where can I find [...] tools / libraries in a easy to use page or section?

There's no central repository of all the available things since they can be loaded from many places (Clojars, Maven Central, other Maven repositories, S3, Git, local files).

But there are community-maintained lists, like the one you've mentioned at https://www.clojure-toolbox.com (fully manual, AFAIK) or the one at https://phronmophobic.github.io/dewey/search.html (automated but only for GitHub). Perhaps there are others but I'm not familiar with them - most of the time, I myself don't find that much value in such services as I'm usually able to find things with a regular web search engine or ask the community when I need something in particular.

They are written in Java, and implement a bunch of interfaces, so the implementation looks complicated, but they are basically just classes with head and tail fields.

https://github.com/clojure/clojure/blob/master/src/jvm/cloju...

Like this.

As a Java/Scala user you should check out Clojure! It is highly recommended (https://clojure.org)

Lisp is not a programming language, but a family of languages ​​with many dialects. The most famous dialects include Common Lisp, Clojure, Scheme and Racket. So after deciding that I was going to learn Lisp, I had to choose one of its dialects.

I learned Clojure to implement a plugin for Metabase (the tool my former company used for creating business dashboards). I probably won’t ever use the language anymore in the future, but learning functional programming was fun and eye-opening.