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0 pointspartdavid6y ago0 comments

At this point Bel doesn't even have numbers. A character is axiomatically a character, not some other thing (like a number in a character set encoding). Isn't it premature to talk about character set encoding or even representation yet? A character is a character because it's a character. But I haven't nearly read through these documents so perhaps I'm not understanding something.

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krapp6y ago· 2 in thread

As far as I know a "character" is a number in a character set. "A character is a character because it's a character" doesn't make any sense, at least not in the context of a programming language. A character is a character because it maps to a letter or glyph, and that requires a specific encoding.

The Bel spec contains the following:

    2. chars

    A list of all characters. Its elements are of the form (c . b), where
    c is a character and b is its binary representation in the form of a 
    string of \1 and \0 characters.

In other words, even in Bel a character is still a "number" in a character set encoding. The "binary representation" isn't mentioned as being a specific encoding, which means it's assumed to be UTF08 or ASCII.

Also, Bel does have numbers, apparently implemented as pairs. Go figure.

partdavidOP6y ago

You're right that I need to review more of the Bel spec (which as you point out does in fact implement numbers).

But I am trying to read this in the spirit in which it's intended, as irreducible axioms. And so I don't think it's true that a character needs a representation from the perspective of Bel.

Consider if pg had approached this more like I would have, and started with integers and not characters as a built-in. Does an integer need a "representation"? At least, in a language that is not designed to execute programs in, like Bel? An implementation (with the additional constraints like width, BCD vs two's complement vs whatever, radix, etc) would need one, but the formal description would not.

Thanks for exploring the subject.

fao_6y ago

> You're right that I need to review more of the Bel spec (which as you point out does in fact implement numbers).

Can I ask why you claimed that it didn't have numbers or characters? It seems an odd thing to claim without actually having that knowledge in the first place.

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