shawa_a_a · HackerTrans

shawa_a_a

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Show HN: Xlerb – A Compiled "Forth" for the Beam

6 pointsby shawa_a_a8 เดือนที่ผ่านมา0 comments

Tube: A subway route planner in Dyalog APL (2011)

dfns.dyalog.com

23 pointsby shawa_a_a9 เดือนที่ผ่านมา4 comments

Show HN: Reviving a 20 year old OS X App

andrewshaw.nl

73 pointsby shawa_a_aปีที่แล้ว32 comments

comments

9 เดือนที่ผ่านมาdiscuss

It's been a long time since I've programmed Prolog so I'm not sure if these ideas are even relevant (global state might be more than enough!) ; but at first impressions from the readme this really reminds me of ETS

https://www.erlang.org/doc/apps/stdlib/ets.html

Essentially system-global state under named tables.

Have/did you consider having named `env` instances? This would allow for say, feature flags to be kept in a `features` set of relations.

You could also draw from Erlang's 'match specs' and query with a predicate over the keys.

9 เดือนที่ผ่านมาdiscuss

I think that's going to be hard to find, depending on your definition of 'regular', tbh.

The BEAM's grown up along with Erlang and so the culture and optimisations are built up all around function application, list processing, recursion, and pattern matching etc.

https://github.com/llaisdy/beam_languages is a decent list of the diverse languages that have been implemented on it, but nothing quite like 'regular for and while loops'.

The BEAM itself is a plain aul register machine though, so it could be done!

https://www.erlang.org/blog/a-brief-beam-primer/

9 เดือนที่ผ่านมาdiscuss

They're probably using some features of LiveView; I'm not too familiar with how HTMX works, but with LiveView you can define all of your logic and state handling on the _backend_, with page diffs pushed to the client over a websocket channel (all handled out of the box).

It comes with some tradeoffs compared to fully client-side state, but it's a really comfortable paradigm to program in, especially if you're not from a frontend background, and really clicks with the wider Elixir/Erlang problem solving approach.

https://hexdocs.pm/phoenix_live_view/js-interop.html#handlin...

Hooks let you do things like have your DOM update live, but then layer on some JS in response.

For example you could define a custom `<chart>` component, which is inserted into the DOM with `data-points=[...]`, and have a hook then 'hydrate' it with e.g. a D3 or VegaLite plot.

Since Phoenix/LiveView is handling the state, your JS needs only be concerned about that last-mile JS integration; no need to pair it with another virtual DOM / state management system.

https://hexdocs.pm/phoenix_live_view/js-interop.html#client-...

11 เดือนที่ผ่านมาdiscuss

For BEAM MCP you probably want to look at TideWave, which runs _in your application_ to give the LLM context and an execution environment.

https://hexdocs.pm/tidewave/mcp.html

11 เดือนที่ผ่านมาdiscuss

I've heard of domain fronting, where you host something on a subdomain of a large provider like Azure or Amazon. Is this what you're talking about when you say

> - Host on a piece of infrastructure that's so big that you can't effectively block it without causing a major internet outage (think: S3, Cloudflare R2, etc).

How can one bounce VPN traffic through S3? Or are you just talking about hosting client software, ingress IP address lists, etc?

11 เดือนที่ผ่านมาdiscuss

Surprised to not see Acko.net mentioned in comments already - he uses similar aids in one of his blog posts to break down complex numbers and ultimately fractals.

Likely right up your street!

https://acko.net/blog/how-to-fold-a-julia-fractal/

ปีที่แล้วdiscuss

Agreed - updated with colour again

ปีที่แล้วdiscuss

It’s not the most accessible colour scheme - I’ll have a look and tweak it so dark mode is more readable.

I’d definitely be really grateful for help with that! I’m not planning to publish to the Mac App Store, but it would be great to have the build step a bit more compliant with current practises.

ปีที่แล้วdiscuss

Since going down this rabbit hole, I gave Anki another fair shot and actually RTFM :) the blog post warrants an update

https://docs.ankiweb.net/deck-options.html#learning-steps Details what _actually happens_ when you pick again/hard/good etc. I much prefer understanding this to the vibes-based approach of “did you pause before answering”.

Secondly turns out you can indeed very easily set up type-to-answer in a deck by editing the front template and adding

{type:Field}

where field is the answer part of the card’s data.

So… I’m actually using Anki again. I’m still very happy I did this, it was a fun little journey!

ปีที่แล้วdiscuss

I have been bedroom DJing, and wanting to expand what I can do with the hardware I already have.

Using `midiex` for Elixir I’ve written a fully fledged driver for Ableton Push, letting me use it as essentially a 4-deck version of Pioneer’s DDJ-XP2 sub controller with Rekordbox.

It implements basic statefulness so that the rotary encoders can be used, as well as a paging system so the 64 performance pads can be mapped to different functions. It also supports track browsing and loading, which is helpful if you want to use say DVS with an external mixer and don’t want to be hunched over a laptop dragging tracks around.

It’s also got some additional capabilities which I’ve not seen on other hardware like dedicated faders for stem separation levels.

It’s been a great exercise in combing two hobbies, learning about MIDI as well as being able to personalise my setup for my own use. I haven’t open sourced any of it just yet whilst I’m still tweaking things but I’d be interested in collaborating with anyone who also has one of these devices and has programmed it. I’m looking to use the display on it next, whose protocol Ableton have some (albeit scant) documentation for.

2 ปีที่แล้วdiscuss

This isn’t exactly the case. The camera has an actuating mirror on the end of the rotating arm that allows it to point at arbitrary angles.

https://youtu.be/aXfTgCCsRSg (T=4:30)

The emulating different lenses part is that with this setup you can parametrically collect specific rays bouncing off the object (presumably the angle of the mirror with respect to radius), and the resulting image will be the same as you’d get from a lens with those parameters.

2 ปีที่แล้วdiscuss

Not the other commenter, but my team has been using Elixir in production (soft real-time distributed systems) for several years to great success. The approachable syntax has been great for folks new to the language coming on board and sort of, not realising they’re “doing FP”.

Generally I’d say Elixir’s lack of “hard” static typing is more than made up for what you get from the BEAM VM, OTP, its concurrency model, supervisors etc.

That said if you’re interested in leveraging the platform whilst also programming with types I’d recommend checking out Gleam (https://gleam.run), which I believe uses an HM type system.

2 ปีที่แล้วdiscuss

A commenter on Reddit [1] pointed out that you can access the hearing test feature directly by using a special URL:

    x-apple-health://HearingAppPlugin.healthplugin/HearingTest

I wonder if there’s a similar deep link to be found to enable Hearing Aid mode?

1: https://www.reddit.com/r/AirpodsPro/comments/1gftyqo/is_the_...

2 ปีที่แล้วdiscuss

It's a bold statement to call something a Prolog successor! Are you aiming for a general purpose logic programming language like Prolog, or targeting the use case of querying knowledge bases?

One of the draws to Prolog is its immensely simple syntax: A.R:B = true in your case would be represented as simply r(A, B).

It looks like you've elevated some set theory properties to syntax, and have added some neat sugar over chained relations. Have you found areas where this really shines as compared to writing more standard Prolog/Datalog queries? I'm afraid I couldn't see many examples on first look at your Github.

2 ปีที่แล้วdiscuss

I would second Prolog as mind-blowing. I've found you're typically confronted with fully engaging with the core of whatever problem you're solving, and only that core. This is probably what can make it so frustrating sometimes as you have no option but to work out the hard stuff nearly immediately; not to mention that unconsidered edge cases, mistakes can cause some pretty opaquely wrong results, or the query not terminating, which can make conventional debugging pretty difficult. The guarantees you get with using the 'pure' core of Prolog do open up some really interesting avenues though, for example Scryer's debugging library is quite neat in affording _semantic_ debugging: https://www.scryer.pl/debug

Just some additional commentary too - I think this post quite misrepresents it with some of the comparisons.

Prolog at its core is SLD Resolution [1] (a form of search) over Horn Clauses [2] (first order logic). Queries posted to the runtime are attempts to find a set of values which will satisfy (cause to be true) the query – whilst SQL is founded on relational algebra which more closely aligned with set theory.

Whilst there's probably some isomorphism between satisfying/refuting a logical predicate, and performing various set operations, I'd say it's a bit of a confusion of ideas to say that SQL is based on 'a subset of Prolog'. The author might be thinking about Datalog [3], which is indeed a syntactic subset of Prolog.

[1]: https://en.wikipedia.org/wiki/SLD_resolution [2]: https://en.wikipedia.org/wiki/Horn_clause [3]: https://en.wikipedia.org/wiki/Datalog

2 ปีที่แล้วdiscuss

The comment character is also configurable:

    git config core.commentchar <char>

This is helpful where you want to use use say, markdown to have tidily formatted commit messages make up your pull request body too.

2 ปีที่แล้วdiscuss

I don’t know about your particular use case, but it is never a bad idea to learn Prolog.

https://www.metalevel.at/prolog

The Power of Prolog is an extremely in depth, comprehensive introduction that starts right from fundamentals, and goes into some pretty advanced topics. It’s a really great resource, with well-produced accompanying videos, and leans into properly grokking the language and the “Prolog way” of problem solving.

I’d make a meta point that learning Prolog and forcing yourself to solve problems the “prolog way” serves as a great exercise in understanding the importance of using the right tool for the job, and working with, rather than in spite of , your tools.

2 ปีที่แล้วdiscuss

In the spirit of scratches, it was only at a recent 70mm film screening that I spotted the rig used for the floating pen scene as Floyd falls asleep in the shuttle.

As the weightlessness begins, his pen floats away - if you look really really carefully you can spot that it’s actually embedded in a thin plastic film which is rotating about an axis, given away by minute scratches on its surface.

3 ปีที่แล้วdiscuss

For anyone else interested, and to clarify, "the Book of Kells experience" is to stand in for the exhibit in the Old Library while it's closed for renovations until 2025 [1].

Rather than and Old Library, it's a huge red prefab building in New Square. Might not be quite as impressive as the original tour.

1: https://www.tcd.ie/old-library-campaign/faq/

3 ปีที่แล้วdiscuss

I've been intrigued enough to pull down Gnu COBOL and attempt to write some simple programs, and found it to be quite an alien universe in and of itself. Can you give any examples of the fully-fledged mainframe world differing from running it on x86/arm?