2 ms·
> without the ambiguity There's no ambiguity! In J, all (with some exceptions) operations work on arrays, period. `1 + 1` is not an addition of two scalars, bu
by klibertp 5y ago
> without the ambiguity
There's no ambiguity! In J, all (with some exceptions) operations work on arrays, period. `1 + 1` is not an addition of two scalars, but instead of two arrays of length 1. As I mentioned, you can have scalars, but a) they still live in arrays and b) you can't do anything with them without unboxing. So there's no ambiguity, as far as I can tell.
Also, APL and J are implemented as intepreters, but that doesn't preclude using SIMD instructions when executing expressions. I'm 100% sure the operations are not "implemented naively" :)
- rscho 5y ago> `1 + 1` is not an addition of two scalars, but instead of two arrays of length 1 I think that's true of (Dyalog) APL, but not of J [1]. APL follows the nested array model (that you describe), while J follows the flat array model that does have true scalars. [1] https://aplwiki.com/wiki/Array_model#Flat_array_theory https://aplwiki.com/wiki/Array_model#Flat_array_theory
- dzaima 5y agoAFAIK, J considers `1` to be an array - `L. 1` and `L. 1 2` both give 0 (`L. (1;2)` gives 1). APL's simple scalar numbers are much more like regular numbers in non-array languages.