alt.hn

5/18/2026 at 7:12:40 AM

The Mercury logic programming system

 https://github.com/Mercury-Language/mercury

by Antibabelic

5/20/2026 at 1:09:32 PM

Something you might find interesting to look at is Rego, a datalog-derived language been used for writing security policies. Rego is dynamically typed, so no real protection. It's input is basically JSON and it can apply JSON-Schema, but that's it. I think it would be interesting to look at Rego as a restricted version of this and see what types buys for a Rego user. It's probably one of the larger areas of logic programming and has brought people into the fold, so to speak.

by mattgoupil

5/20/2026 at 2:18:56 AM

Oh wow, Zoltan was one of my lecturers at UniMelb, and in one semester we were tasked with learning his Mercury language. So good to see it thriving still.

by ElectroSlayer

5/20/2026 at 7:57:43 AM

I TA-ed for Zoltan's 2nd year "learning how to use bash/gdb/etc" class and it was a lot of fun. I hope they're still teaching that class.

by zeafoamrun

5/20/2026 at 12:48:17 PM

It was called "433-252 Software Engineering Principles & Tools" until ~2008 I think (433-244 before that) but then it seems to have been reorganised. Tbh, Unimelb Comp Sci is a shadow of it's former self, a victim of the 'Melbourne Model' common core sausage factory concept.

by angry_octet

5/20/2026 at 1:04:05 PM

Is it the same model as the "Bologna process" in Europe, which is kind of funny because "Bologna" also refers to a type of sausage in the US of A.

by ofrzeta

5/20/2026 at 12:42:15 PM

I hope he's stopped drinking Fanta.

by angry_octet

5/20/2026 at 8:01:11 AM

prince, a high quality html renderer used for typesetting, is written in mercury:

https://www.princexml.com/doc/acknowledgements/

by 5-

5/20/2026 at 2:39:29 PM

Was it written in Prolog at any point in time ?

Perhaps I am misremembering, but my brain is telling me of a CSS or PDF parser written in Prolog.

by srean

5/20/2026 at 3:13:49 AM

There are files in this repository that were last touched 32 years ago. Any reason to be posting it now?

by ororroro

5/20/2026 at 4:30:24 AM

Not that it necessarily applies here, but as a heuristic: https://en.wikipedia.org/wiki/Lindy_effect

by kaonwarb

5/20/2026 at 4:43:05 AM

Interesting point. My understanding of Mercury is that it is hard carried by Zoltan so it has a bus factor of 1.

by ororroro

5/20/2026 at 7:27:20 AM

I always understood it was a teaching language for students who wanted to get programming language implementation experience.

by zeafoamrun

5/20/2026 at 3:18:54 AM

Why is that relevant or noteworthy? There are files that were updated recently too.

by epgui

5/20/2026 at 3:50:47 AM

Why the aggression? This language while cool has existed for decades and never taken off. I just wanted a reason to believe it relevant so I could have an excuse to take another look.

by ororroro

5/20/2026 at 4:10:28 AM

Why do you think "oldest untouched file" is a good metric for relevance? Do you know what is the oldest untouched file in gcc or Python?

by hackyhacky

5/20/2026 at 2:42:27 PM

"Taking off" is an unreliable metric of capability and fitness to a problem you may want solved.

by srean

5/20/2026 at 2:09:37 PM

There was no aggression.

by epgui

5/20/2026 at 7:59:45 AM

Damn dude you're making me feel old

by zeafoamrun

5/20/2026 at 4:34:20 AM

Last release was in 2023.

It is effectively dead.

This is a terrible shame, because this would have been an nice modern alternative to Prolog.

by KnuthIsGod

5/20/2026 at 7:01:24 AM

Last commit was 2 minutes ago. Seems like a better measure than releases, different projects have different release cadences.

by kryptiskt

5/20/2026 at 5:19:42 AM

But the repo has had fairly consistent commits since then. Not huge activity, but not sure I'd call it dead.

by jamwise

5/20/2026 at 3:04:52 PM

You say “dead”, I say “stable”. Not everyone wants to base their work on a moving target.

by wduquette