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I respect what you're saying here about a "C abstract machine" that's disjoint from any particular real hardware, and that it introduces its own troubles throug

I respect what you're saying here about a "C abstract machine" that's disjoint from any particular real hardware, and that it introduces its own troubles through the abstraction, and I think with agree with all that. But I'm not sure how to draw that out of your original comment, or even how to interpret the original comment while "ignoring the Rust stuff entirely". That comment seems to be suggesting that Rust exposes its users to the bare metal just as much as C does, so if you take that comparison out, it doesn't seem like it's saying anything at all. C is flawed, and is not even ideal as a window into bare metal (because of its own abstract machine), but Beej noted that it's more connected than any "present-day" language, and that claim does seem to hold.

tialaramex 4y ago
Well, let's just try ripping all mention of Rust out: ""While obviously C is closer to the metal than say, Python, I am increasingly dubious about the value of any of these high level languages (yes, even C) to learn "How the machine really works". I reckon it's probably more instructive to write a little bit of ARM assembly than to learn enough C to get to the same place today."" Now, why am I talking about "How the machine really works". Well, here's the next line from Beej: > When you learn C, you learn about how software interfaces with computer memory at a low level You don't. You're learning about how C software interfaces with the memory of C's abstract machine, but that's not how your machine's memory works, not even close. For example C just magically ensures the alignment is correct all the time, but the actual memory relies on programmers to ensure they only perform aligned access, unaligned access may blow up your whole program or make it enormously slower, which is worse ? On the other hand C's Pointers are not just addresses. Even though C makes them look more like they are than many languages with a pointer type, they still aren't just addresses. If you mistake them for addresses, you'll get punished by your compiler, although just exactly when is hard to predict - this is a game of Russian Roulette. However the actual memory in your computer really does just have addresses and they're just numbers like any other numbers.

tialaramex 4y ago

Well, let's just try ripping all mention of Rust out: ""While obviously C is closer to the metal than say, Python, I am increasingly dubious about the value of any of these high level languages (yes, even C) to learn "How the machine really works". I reckon it's probably more instructive to write a little bit of ARM assembly than to learn enough C to get to the same place today."" Now, why am I talking about "How the machine really works". Well, here's the next line from Beej: > When you learn C, you learn about how software interfaces with computer memory at a low level You don't. You're learning about how C software interfaces with the memory of C's abstract machine, but that's not how your machine's memory works, not even close. For example C just magically ensures the alignment is correct all the time, but the actual memory relies on programmers to ensure they only perform aligned access, unaligned access may blow up your whole program or make it enormously slower, which is worse ? On the other hand C's Pointers are not just addresses. Even though C makes them look more like they are than many languages with a pointer type, they still aren't just addresses. If you mistake them for addresses, you'll get punished by your compiler, although just exactly when is hard to predict - this is a game of Russian Roulette. However the actual memory in your computer really does just have addresses and they're just numbers like any other numbers.