BQN VS swift-algorithms

I recommend checking BQN at https://mlochbaum.github.io/BQN/ and the YouTube channel code_report by Conor Hoekstra (and also "Composition Intuition by Conor Hoekstra | Lambda Days 2023"). It is well documented.

I don't put a lot of stock in the "write-only" accusation. I think it's mostly used by those who don't know APL because, first, it's clever, and second, they can't read the code. However, if I remember I implemented something in J 10 years ago, I will definitely dig out the code because that's the fastest way by far for me to remember how it works.

This project specifically looks to be done in a flat array style similar to Co-dfns[0]. It's not a very common way to use APL. However, I've maintained an array-based compiler [1] for several years, and don't find that reading is a particular difficulty. Debugging is significantly easier than a scalar compiler, because the computation works on arrays drawn from the entire source code, and it's easy to inspect these and figure out what doesn't match expectations. I wrote most of [2] using a more traditional compiler architecture and it's easier to write and extend but feels about the same for reading and small tweaks. See also my review [3] of the denser compiler and precursor Co-dfns.

As for being read by others, short snippets are definitely fine. Taking some from the last week or so in the APL Farm, {⍵÷⍨+/|-/¯9 ¯11+.○?2⍵2⍴0} and {(⍸⍣¯1+\⎕IO,⍺)⊂[⎕IO]⍵} seemed to be easily understood. Forum links at [4]; the APL Orchard is viewable without signup and tends to have a lot of code discussion. There are APL codebases with many programmers, but they tend to be very verbose with long names. Something like the YAML parser here with no comments and single-letter names would be hard to get into. I can recognize, say, that c⌿¨⍨←(∨⍀∧∨⍀U⊖)∘(~⊢∊LF⍪WS⍨)¨c trims leading and trailing whitespace from each string in a few seconds, but in other places there are a lot of magic numbers so I get the "what" but not the "why". Eh, as I look over it things are starting to make sense, could probably get through this in an hour or so. But a lot of APLers don't have experience with the patterns used here.

[0] https://github.com/Co-dfns/Co-dfns

[1] https://github.com/mlochbaum/BQN/blob/master/src/c.bqn

[2] https://github.com/mlochbaum/Singeli/blob/master/singeli.bqn

[3] https://mlochbaum.github.io/BQN/implementation/codfns.html

[4] https://aplwiki.com/wiki/Chat_rooms_and_forums

Uiua is an interesting new language. Strongly influenced by APL and BQN, it's array-oriented and stack-based. To explore it briefly, I will walk through my solutions to this week's Perl weekly challenge (242).

https://mlochbaum.github.io/BQN/

Forth and Lisps tend to be fairly visual syntax free as well.

I'm just speculating though, looking for someone with experience to confirm or rebuke.

> Are there any other languages that use glyphs so heavily?

APL (the first, invented in the 1960s): https://en.wikipedia.org/wiki/APL_(programming_language)

BQN (a modern APL, looks like an inspiration for Uiua though I don't know): https://mlochbaum.github.io/BQN/

Too many smaller esoteric languages to count.

There is no need to have a specific keyboard. The actual solution depends on what APL you're using, but the principle is the same. The various symbols are available on the regular keys, and you use some way to indicate that you want the APL symbol rather than the regular symbol.

Dyalog has two different IDE's the support this. Ride uses backquote by default, while the windows IDE uses control.

Kap uses backquote in all its interfaces. Here's what it looks like in the web version: https://kapdemo.dhsdevelopments.com/clientweb2/

Likewise, BQN does the same thing, but uses backslash: https://mlochbaum.github.io/BQN/

When using GNU APL there is an Emacs mode available (which I am the author of) that provides an input method.

So the long story short, you should be able to get going with any array language without getting any special keyboard.

Vouch for array programming, but also BQN. Modern, very good documentation, a bit less confusing than APL imo.

For anyone looking to get into array programming, I'd recommend https://mlochbaum.github.io/BQN/. I'm no expert but I had a lot of fun using it for Advent of Code last year. I found it to be a lot more sensible and modern feeling than J (the only other one I've tried).

There’s also at least BQN, which I suspect is the language used in those comments:

https://mlochbaum.github.io/BQN/

While you are correct about the stdlib, check out swift-algorithms (https://github.com/apple/swift-algorithms). It's written by Apple and has several interesting methods.

We used Swift Algorithms once or twice. It just depends on the app. I suggest starting with the WWDC video.

Install swift-algorithms and use min/max(count:by:)

#!/usr/bin/env swift sh import Algorithms // https://github.com/apple/swift-algorithms struct StandardInput: Sequence, IteratorProtocol { func next() -> String? { return readLine() } } func markerEnd(for signal: String, markerLength: Int) -> Int { return Array(signal.windows(ofCount: markerLength)) .firstIndex { Set($0).count == markerLength }! + markerLength } let signals = StandardInput().compactMap { $0 } let part1 = signals.map { markerEnd(for: $0, markerLength: 4)}.reduce(0, +) let part2 = signals.map { markerEnd(for: $0, markerLength: 14)}.reduce(0, +) print("part 1 : \(part1)") print("part 2 : \(part2)")

#!/usr/bin/env swift sh import Algorithms // https://github.com/apple/swift-algorithms typealias Label = Character typealias Instruction = (amount: Int, source: Int, destination: Int) struct StandardInput: Sequence, IteratorProtocol { func next() -> String? { return readLine(strippingNewline: false) } } let sections = StandardInput() .compactMap { $0 } .split(separator: "\n") .map { Array($0) } let stacks = parseStacks(from: sections[0]) let instructions = parseInstructions(from: sections[1]) print(apply(instructions, to: stacks, oneAtATime: true)) print(apply(instructions, to: stacks, oneAtATime: false)) // MARK: - Private private func parseStacks(from section: [String]) -> [[Label]] { let crates = section.map { let start = $0.index($0.startIndex, offsetBy: 1) return Array($0.suffix(from: start).striding(by: 4)) } let stackCount = crates[0].count var stacks: [[Label]] = Array(repeating: [Label](), count: stackCount) crates.reversed().forEach { for (index, label) in $0.enumerated() { stacks[index].append(label) } } return stacks.map { $0.filter { $0.isLetter } } } private func parseInstructions(from section: [String]) -> [Instruction] { return section.map { let tokens = $0.dropLast().split(separator: " ") return (Int(tokens[1])!, Int(tokens[3])! - 1, Int(tokens[5])! - 1) } } private func apply( _ instructions: [Instruction], to stacks: [[Label]], oneAtATime: Bool ) -> String { var stacks = stacks instructions.forEach { let cargo = Array(stacks[$0.source].suffix($0.amount)) stacks[$0.source] = stacks[$0.source].dropLast($0.amount) stacks[$0.destination].append( contentsOf: oneAtATime ? cargo.reversed() : cargo ) } return String(stacks.map { $0.last! }) }

Swift. Algorithms contains chunks(ofCount: 3) but I had to write chunks(totalCount:) myself.

Algorithms has `max(count:)` now. 💻🖥️

Create windows of 4 elements.

There is also a swift algorithm package that’s a precursor to the standard library if you want to examine legit implementation built into Swift.

I used Algorithms and took inspiration from Kotlin with it's zipWithNext function.