[JesseAldridge]

> add each number in a list x to each number in the corresponding row of a two-dimensional array y

I mean, I could write a function `add(x, y)` that does that in any language. You could even inspect the data or type to make it polymorphic. I believe NumPy does this, for example.

Skimming the rest of the article, I don't get how this is different from any other language. The primary difference seems to be the function names are all one or two characters long for some reason. I must be missing something...

[plorkyeran]

The fact that they're built into the language is in fact significant. Yes, you obviously could implement J's set of primitives in nearly any language and then use those. In practice though, you won't, and if you did then many of the people reading the code wouldn't understand it very well.

Imagine if lodash was built into JS, and optimized by the implementations to the point where it was faster than not using it. Idiomatic JS would look very different even though it hasn't made anything possible that wasn't previously possible.