Re: [ANN and RFC] Bifurcan: impure functional data strucures

I'm a bit late to this, but it caught my eye. The only common use case I have for mutating data structures in Clojure is when storing state in a global map (similar to Om.Next), but I almost always make them atomic to account for nondeterminism in the order operations on them will finish.

Re: [ANN and RFC] Bifurcan: impure functional data strucures

Both, actually. The algorithm incrementally builds a tree via simulation. There's a step of traversing the current version of the tree to find a leaf, which requires immutability, as I have to remember the path taken (the path is generated via simulation, not by walking an existing tree

Re: [ANN and RFC] Bifurcan: impure functional data strucures

Are you relying on the immutability of these structures, or are they effectively always transient? On Sun, Apr 23, 2017 at 11:02 AM Dave Dixon wrote: > FWIW, the use-case I have essentially involves Monte Carlo simulations. So > we start with a state (non-empty map), and

Re: [ANN and RFC] Bifurcan: impure functional data strucures

FWIW, the use-case I have essentially involves Monte Carlo simulations. So we start with a state (non-empty map), and then make a series of modifications to it. Various statistics are held in hash-maps keyed by the state, so there's a lot of lookups and modifications in those maps. That said,

Re: [ANN and RFC] Bifurcan: impure functional data strucures

Sure, happy to elaborate. Bifurcan offers potential performance wins a few different ways: * We can use standard Java equality semantics, bypassing all the overhead of the hash calculations and enhanced numeric equality checks (this can lead to moderate performance gains) * We can use a mutable

Re: [ANN and RFC] Bifurcan: impure functional data strucures

Sounds great. If you have time, I'd certainly like to hear your thoughts on the issues of equality semantics and transients, maybe I can ponder and make some suggestions based on my target use-case. On Tuesday, April 18, 2017 at 9:32:32 AM UTC-7, Zach Tellman wrote: > > To be clear, my

Re: [ANN and RFC] Bifurcan: impure functional data strucures

Looks cool! I'm going to mine this for ideas and potentially use it. FWIW I've also been implementing some Java functional data structures for my language design experiments. If anyone is interested happy to share code, my own motivations were: - I wanted decent persistent Lists, Sets, Maps

Re: [ANN and RFC] Bifurcan: impure functional data strucures

To be clear, my intention was always to wrap the implementations in the appropriate Clojure interfaces, and I don't believe that will cause much, if any, of a performance hit (inlining is magic). However, there are some real questions regarding how to expose non-standard equality semantics, and

Re: [ANN and RFC] Bifurcan: impure functional data strucures

Stared at this a bit yesterday. Seems like if you want to leverage spec while using bifurcan, then the bifurcan types need to have the Clojure wrapper. The alternative appears to be re-implementing at least a large subset of collection-related spec code, which is a lot to bite off. Also tried

Re: [ANN and RFC] Bifurcan: impure functional data strucures

What is the issue with wrapping in Clojure interfaces? Added overhead of function calls? I'm finding myself in the process of doing some of this, at least for constructors. Also thinking of generating predicates/generators for use with spec. On Monday, March 27, 2017 at 9:51:46 AM UTC-7, Zach

Re: [ANN and RFC] Bifurcan: impure functional data strucures

I do a lot of work with data structures, so this, I think, would be useful to me. For the immutable data structures, it seems like they could be done as a drop-in replacement for the Clojure built-ins. There are a couple new functions for splitting and concatenating. I'd recommend following

Re: [ANN and RFC] Bifurcan: impure functional data strucures

I think this would solve an issue I'm facing. I'm working on implementing variations of Monte Carlo tree search for very large trees, with states and actions represented by maps. There are several lookup tables indexed by either state or state-action pairs. I haven't done any detailed

Re: [ANN and RFC] Bifurcan: impure functional data strucures

Both the 'List' and 'Map' data structures in Bifurcan use innovative approaches that were published after Clojure's original release [1] [2]. In the case of the immutable map, you get faster iteration and the structural invariants allow for some clever stuff w.r.t. equality checks and set

Re: [ANN and RFC] Bifurcan: impure functional data strucures

I'm not well versed enough in these data structures to know this without asking (apologies if it's really obvious to some people): is there opportunity to improve Clojure's built-in data structures with Bifurcan rather than trying to wrap Bifurcan's structures in Clojure? As an aside, I want

Re: [ANN and RFC] Bifurcan: impure functional data strucures

Benchmarks are available here, and the Clojure benchmarks make use of transients wherever possible: https://github.com/lacuna/bifurcan/blob/master/doc/benchmarks.md. More generally, while transients are often used in practice to quickly construct a read-only data structure, the more formal

Re: [ANN and RFC] Bifurcan: impure functional data strucures

> On Mar 27, 2017, at 09:51, Zach Tellman wrote: > > They also provide high-performance mutable variants of the data structure > which share an API with their immutable cousins. How does their performance compare to Clojure's transients? Transients are slower than Java's

[ANN and RFC] Bifurcan: impure functional data strucures

This is a slightly irregular announcement, because it's not for a Clojure library. Rather, it's for a library written purely in Java: https://github.com/lacuna/bifurcan. This is a collection of mutable and immutable data structures, designed to address some of my personal frustrations with