Hacker News new | ask | show | jobs
by electroly 340 days ago
I always thought APL was written in the wrong direction. It writes like a concatenative language that's backwards--you tack things onto the front. NumPy fixes it by making the verbs all dotted function calls, effectively mirroring the order. e.g. in APL you write "10 10 ⍴ ⍳100" but in NumPy you write "np.arange(1, 101).reshape(10, 10)". Even if you don't know either language, you can tell that the APL version is the reverse of the Python version.

My hot take is that Iverson was simply wrong about this. He couldn't be expected to predict code completion and then LLMs both wanting later tokens to depend on earlier tokens. SQL messed it up, too, with "from" not coming first. If APL were developed today, I think left-to-right evaluation would have been preferred. The popularity of dotted function calls in various languages makes it reasonably clear that people like tacking things onto the end and seeing a "pipeline" form from left to right.
2 comments
beagle3 340 days ago
APL was designed as a notation for math; if you pronounce it properly, it makes more sense than numpy:

The 10 by 10 reshaping of counting to 100

link
isoprophlex 340 days ago
Numpy: Counting to 100, then reshaped to 10 x 10. Doesn't really seem all that different to me.
link
beagle3 340 days ago
It’s not very different, but it’s the numpy way is not the math way: when you talk math, you say “the exponent of the absolute value of the cosine of x”, like in APL, not “take x, get its cosine, then take the absolute value, and then get its exponent”

In fact, for many things, you so the math way in numpy as well. But in other things, the dot/object-oriented way is preferred.

APL is just consistent, terse, mathematical notation.

link
fwip 340 days ago
With complicated formulas, it often makes more sense and can give more guidance by first talking about the last operations to be applied. This seems to match the LLM structure, by starting by describing what we want, and then filling in the more specialized holes as we get to them. "Top-down" design vs "bottom-up".

Your insight about APL being reverse-concatenative is very cool.

link