rspencer · HackerTrans

vor 11 Monatendiscuss

It is equivalent because it's not a plus-scan but a (0^+)-scan which resets every time it hits a null (there's a more in depth explanation here https://robertandrewspencer.com/aoc_2022_1/ )

Perhaps q did both force you to consider what was happening, and hide it from you...

rspencer

vor 11 Monatendiscuss

It was intended to split a list of `int|None` into its non-none stretches. Much like how `string.split('x')` splits a string by matching the character 'x'

rspencer

vor 11 Monatendiscuss

I had a similar thought a few years ago with an Advent of Code problem for which my solution in python might have been

  max(map(sum, input_list.split(None)))

To decipher this the eye has to jump to the middle of the line, move rightwards, then to the left to see the "map" then move right again to see what we are mapping and then all the way to the beginning to find the "max".

The author would probably suggest rust's syntax* of

  values.iter().split(None).map(Iterator::sum).max().unwrap_or(0)

but I was learning q at the time so came up with the much clearer /s, right to left

  max((0^+)\)l

*: Though neither python nor rust have such a nice `.split(None)` built in.

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