by cpp_frog on 2/16/24, 12:57 PM with 46 comments
by mjhay on 2/16/24, 4:15 PM
https://www.algebraicjulia.org/
There's some blog posts that are also interesting:
by Verdex on 2/16/24, 3:08 PM
http://mgs.spatial-computing.org/PUBLICATIONS/lami-RR72--com...
As far as I can tell, they're trying to model things like chemical reactions (and other stuff) where given a bunch of "stuff" in some solution it will combine with other "stuff" if it's in the same topological neighborhood (which I think is basically the idea that ALL of the "stuff" doesn't have to be next to each other b/c if you let a solution just sit there eventually reactions are going to react).
It's kind of neat, but their website seems to indicate that it is not being actively supported. Or at the very least they don't seem to have any reason to make publicly available documentation after since around 2010.
EDIT: So for example, you could use their "trans" transform primitive to implement conway's game of life by defining the birth rule as a pattern of an empty cell with three alive cells and a transform that results in the empty cell being alive and the alive cells being the same. The death rules in similar fashion. Neighbor here would be defined as being physically next to something (but the point is that because this is about topologies, then neighbor doesn't have to mean physical proximity ... although I'm not sure where that's defined ... in the collection maybe?).
And then you just run the transform on a collection with some initial state.
EDIT EDIT: Yeah, the notion of neighbor is defined on the collection. This allows you to use the same transform on different collection types and get the appropriate result.
ALSO checkout figure 5 in the PDF I linked because it's an incredibly concise description of exactly what they're doing.
EDIT EDIT EDIT:
This also feels vaguely similar to what the Egison language is doing with their pattern matching. Documentation for Egison feels better at least to me.
However, I don't think that egison allows you to define arbitrary notions of neighbors in a collection like MGS does. But I haven't exactly tried to use it very much.
by hackandthink on 2/16/24, 3:19 PM
There are some beautiful pictures.
https://content.wolfram.com/sites/43/2021/11/1110swimg46.png
https://writings.stephenwolfram.com/2021/11/the-concept-of-t...
by misja111 on 2/16/24, 1:44 PM
by whosthatguy on 2/16/24, 5:38 PM
> 2. computes a new collection C as a function f of B and its neighbors,
> 3. and specifies the insertion of C in place of B into A.
This sounds a lot like the presentation of comonads as directed containers (e.g. https://arxiv.org/abs/1408.5809).
by reuben364 on 2/16/24, 2:06 PM
by andoando on 2/16/24, 6:17 PM
by anon291 on 2/16/24, 1:48 PM
by HackerThemAll on 2/16/24, 2:54 PM
> 1, 1+1, 2+1, ():set
> builds the set with the three elements 1, 2 and 3
Regarding the "():set" part, and the "():something" idiom repeating in the article, is that from the same competition for the most absurd syntax where Golang got most of its awkwardness?
