Even in the internal code (the guts; which you might have to look at, coding is not just about APIs), it is possible to have fun with Unicodes: [image] Happy hacking!

At the danger of repeating myself once too often: Unicode used to write source code (not as data or as commentary) is a BAD IDEA. It makes source code NOT WYSIWYG. Recall that programming fonts go to great lengths to distinguish 1 and l and 0 and O etc. Why? Because it avoids confusion. With Unicod…

I think you mean “Ambiguous Unicode characters used to write source code is a bad idea” :slight_smile: Because I don’t think there’s anything wrong with writing σ² = 1.2 in code. Obviously some judgement is required to decide what could be ambiguous and it’s easier to get wrong than if you restric…

There are at least three symbols σ in unicode that look the same: https://util.unicode.org/UnicodeJsps/confusables.jsp?a=σ&r=None

[image] PetrKryslUCSD: With Unicode it is so easy to spoof by substituting look-alikes! That flies in the face of the need to read source code unambiguously. I think we all agree that writing obfuscated code is a bad idea (except as a party trick ), Petr. (As others pointed out, you can do th…

Good catch! I think the right conclusion here is to not use “MALAYALAM DIGIT ZERO” in Julia code. I mean, two ambiguous characters are a problem if you use both. If it’s obvious that people use only one of them then there’s no problem. If you disagree with me I guess you never use l in your code: U…

[image] sijo: If you disagree with me I guess you never use l in your code (I use ℓ = \ell TAB when I need a single-character integer-valued l identifier, just like I do in mathematical papers. Unicode to the rescue! :wink: )

[image] stevengj: ℓ Which has three lookalikes.

[image] PetrKryslUCSD: [image] stevengj: ℓ Which has three lookalikes. … that I don’t use, so no problem. (Whereas I use I and | and the number 1 fairly often, though to be fair I also try to use a programming font where these look distinct from l.)

Well, my point was that you used \ell in order to avoid confusion with I, 1, l. Yet, At the same time you introduced possible confusion between ℓ, ℓ, and 𝓵.

Warning against Unicode confusables

Internals & Design

stevengj January 12, 2024, 3:24pm 10

(Moved to new thread since this a different topic focus. See also previous discussion in Unicode: a bad idea, in general)

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Warning against Unicode confusables

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