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GOTOphobia considered harmful in C

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Re: GOTOphobia considered harmful in C

#191

Post by Gibbon1 »

SOLAR_FIELDS wrote: post #182
eric__cartman wrote: post #147

Earlier quoted context omitted.

The ATmega 328P an Arduino Uno or Nano uses has 2KB of memory and 32KB of flash storage for the program. Having some sort of micropython interpreter there would be impossible, and even if it could be achieved, somone still has to write the low level C/ASM code to make it all work. For many embedded systems, low level languages like C or C++ (perhaps Rust for a lot of ARM micros) is the only sensible choice. If it's n…

I hope Rust takes off for embedded programming. I've been working with ESP32 and C is really the only choice if you are doing anything remotely fancy or resource constrained

What bothers me about rust is the designers are people that have been bitten hard by working on browsers written in C++ with it's manual memory management and no way to enforce object lifetimes. Rusts solution to that seems like a big hammer when it comes to embedded where you usually have either stack allocated or compile time allocated objects.

Re: GOTOphobia considered harmful in C

#192

Post by lmm »

JKCalhoun wrote: post #151
preseinger wrote: post #120

Earlier quoted context omitted.

of course nobody should be writing C any more, for exactly the reason you're demonstrating in this comment

If you're steeped in C and its quirks, have good coding patterns that allow for it, I say knock yourself out. I'm absolutely coding in C again — writing some old-school games using SDL. After working for decades with various retain/release, garbage-collected, magic-memory™ languages, going back to C feels like programming again. I like it.

> If you're steeped in C and its quirks, have good coding patterns that allow for it, I say knock yourself out.

Somewhere between 95% and 100% of people who think they're "steeped in C and its quirks, have good coding patterns that allow for it" write code that invokes undefined behaviour.

Re: GOTOphobia considered harmful in C

#193

Post by dilyevsky »

arp242 wrote: post #77
ufo wrote: post #50

I always encourage people to go read Dijkstra's GOTO paper, instead of just its title. It's a short and easy read, almost like a blog post. If you pay attention, you can see that the he was talking about spaghetti code vs structured code. It's better when the lexical structure of the source code maps to the execution structure. That is, if you know what is the current line being executed, you have a good idea of what…

The thing is that many people today have never encountered the sort of spaghetti code that Dijkstra was talking about in 1968. There's plenty of confusing and messy code around, but true spaghetti code that GOTOs all over the place and is nigh-impossible to follow has been extremely rare for a long time. I can't recall encountering it in the last 30 years. It easy to misunderstand what he was even talking about becau…

> The thing is that many people today have never encountered the sort of spaghetti code that Dijkstra was talking about in 1968.

I would say js/python callback-based frameworks of today like Twisted (also c++/rust futures) is exactly that

Re: GOTOphobia considered harmful in C

#194

Post by Gibbon1 »

lmm wrote: post #190
eric__cartman wrote: post #147

Earlier quoted context omitted.

The ATmega 328P an Arduino Uno or Nano uses has 2KB of memory and 32KB of flash storage for the program. Having some sort of micropython interpreter there would be impossible, and even if it could be achieved, somone still has to write the low level C/ASM code to make it all work. For many embedded systems, low level languages like C or C++ (perhaps Rust for a lot of ARM micros) is the only sensible choice. If it's n…

> The ATmega 328P an Arduino Uno or Nano uses has 2KB of memory and 32KB of flash storage for the program. And costs the same as an ARM with dozens of megabytes of each.

Cheap ARM Cortex's tend to top out at 128/256k of flash and 8/16/32k of RAM.

Re: GOTOphobia considered harmful in C

#195

Post by jamiek88 »

deckard1 wrote: post #162
Someone wrote: post #103

Earlier quoted context omitted.

> And this is high-quality BASIC by 1979 standards — it’s in a printed book after all. I don’t think that’s true, certainly not for books of that time period. Because the whole field was changing rapidly, writers would often work under tight schedules, and customers would buy about anything because they only had magazines and books to learn from and review sites didn’t exist. I also think that’s bad Basic for the tim…

> comment lines before subroutines would help. That code looks normal to me. I have a ton of BASIC books and magazines. You're talking about a time period before full screen text editors were a thing. It's almost impossible to explain to anyone that didn't have to work with TI-99 BASIC, C64 BASIC, GW-BASIC/BASICA, etc. what it was like. Once you got to QBASIC/QuickBASIC it was done. Life was easy. A few years before…

Wasting RAM on REM’s was just rookie stuff.

I remember chasing bytes with short variable names, abbreviated print statements, reducing spaces as much as possible etc.

I had like 28k to play with and I was 14 years old!

Re: GOTOphobia considered harmful in C

#197

Post by kbumsik »

ufo wrote: post #50

I always encourage people to go read Dijkstra's GOTO paper, instead of just its title. It's a short and easy read, almost like a blog post. If you pay attention, you can see that the he was talking about spaghetti code vs structured code. It's better when the lexical structure of the source code maps to the execution structure. That is, if you know what is the current line being executed, you have a good idea of what…

And the original paper is published even before the first version of C was introduced.

Re: GOTOphobia considered harmful in C

#198

Post by galangalalgol »

Gibbon1 wrote: post #191
SOLAR_FIELDS wrote: post #182

Earlier quoted context omitted.

I hope Rust takes off for embedded programming. I've been working with ESP32 and C is really the only choice if you are doing anything remotely fancy or resource constrained

What bothers me about rust is the designers are people that have been bitten hard by working on browsers written in C++ with it's manual memory management and no way to enforce object lifetimes. Rusts solution to that seems like a big hammer when it comes to embedded where you usually have either stack allocated or compile time allocated objects.

If you code in that style you won't even notice the borrow-checker is there. Unless you have a bunch of shared global state, the the overhead of arc will seem silly on your single core uc.

Re: GOTOphobia considered harmful in C

#200

Post by oconnor663 »

dcow wrote: post #20

If you’ve ever actually written more than toy C, you’ll know gotos are essential for resource cleanup and error handling. Even the famous goto fail was not a goto error, it was a block error (named because a cleanup statement `goto fail;` always executed because of a brace-less if). goto can be abused like any other language construct, but it’s uniquely useful and makes code more simple and easy to reason about when…

I don't think it's essential. I think it can be a reasonable choice, but there are other patterns that can accomplish the same thing, with some upsides and some downsides: https://gist.github.com/oconnor663/b0b32f25301ed5a1af4d07053...
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