An example J file because this link doesn't say much:
https://github.com/jsoftware/data_jd/blob/master/csv/csv.ijs
https://github.com/jsoftware/data_jd/blob/master/csv/csv.ijs
https://github.com/jsoftware/data_jd/blob/master/base/common...
Not that I claim anyone in particular can read it of course. Jd uses a hierarchy of folder, database, table, column that's handled with an object system to share code between them. A folder is just a place to put databases and hardly needs to add anything, while the other levels have a lot of extra functionality. As an inverted database, Jd stores each column in a file, and accesses it using memory mapping.
https://github.com/jsoftware/data_jd/blob/master/base/folder...
https://github.com/jsoftware/data_jd/blob/master/base/table....
(I designed this system when I did some of the early work to turn JDB into Jd as a summer intern)
s=. 0 2}.each _3 _1{<;._2 (;i{ccfiles),'/'
But some languages do not leak knowledge in this way.
There is the concept of beauty in programming languages that the expression of an idea should be succinct. This J code might be beautiful, but unsure.
One of the things that makes me happy is to write beautiful code.
It's catching on within the AI community because the syntax matches well to the kinds of matrix operations common in that field.
I think Nvidia's next chip is going to have a compiler for jlang.
Also, I think they are starting to use it as an 'entry level' language for kids, you know, like grade school.