@Adám each have their strengths. tradfns aren't explicitly encouraged to be used functionally, but dfns are very easily used in code as little helper functions (I over-abused that fact :p)

As long as you don't mix trains and OOP, you'll be fine

@dzaima Oh, you have no idea about the craziness of nested dfns out there…

@Zacharý Even dfns and OOP don't go very well together.

@Zacharý I used gradings and key operator before understanding what is outer product. now thats a messed up learning.

@Adám how nested is crazy?

huh, in my program the highest dfn nesting level is only 4.

@Adám I know about that, that was from when I was a complete rookie to APL. I didn't know about ↑ and ↓, I was trying to implement ⍉ ... yeah that was bad

@Uriel, I'll just delete my comments now for a hat

Copy of my most recent comment: Just copy the PPCG submission part of the TIO link, then copy a portion onto your answer. (Sorry if I am bad at explaining >_<)

@Zacharý 😂😂😂

@dzaima I don't know if this (from dfns) is crazy, but I certainly can't read it:

fnrepl←{                                    ⍝ Function string replacement.
    ⍺←⎕THIS                                 ⍝ default current space.
    1:shy←{⍵~⊂''}⍺.{                        ⍝ shy rslt: changed function list.
        (↓⎕NL 3 4){                         ⍝ target space, names of fns (and ops).
            (⎕NR ⍺){                        ⍝ function source lines.
                ⍺≡⍵:''                      ⍝ no change: ignore.
                ⊢⎕FX ⍵                      ⍝ name of changed fn.

Basically, this is if tradfns didn't exist ,,, because the namespace is called dfns for a reason :)

@Zacharý should we open an APL cw for all the versions we have generated so far for the arrow thingy? 🤔

No, I don't think so.

They're pretty different

Now, for the array-percent one which had like 6 different APL answers in 3 different versions, that would've been a good idea

@Zacharý which one?

@Uriel I don't see the point of bunching answers together. I quite like when a challenge has several answer posts in the same language.

@Adám me too. I was just reffering to the sheer amount of our editings

This question

@dzaima One of my first projects at Dyalog was updating this dfn. I couldn't read it, so I translated it to a tradfn, which after updating ended up looking like this.

There are 4 answers, one in Dyalog v16, one in GNU APL, and one in Dyalog v14.