5 ms·

I wonder what the performance impact is. Why do young students no longer learn C? Don't you want to be closer to the underlying OS?

coldtea 11y ago
>Why do young students no longer learn C? Who said they don't? This project is about porting existing stuff, for interoperability, etc. Not as a way to "avoid learning C". >Don't you want to be closer to the underlying OS? No, why would I want to do that unless I have a specific need for that?
- vezzy-fnord 11y ago
  No, why would I want to do that unless I have a specific need for that? At least if you're using a Unix-like system, then understanding POSIX is essential for knowing how things work starting on an intermediate level.
  - tormeh 11y ago
    And why would I want to understand how things work down in the OS? Anyway, C is a horrible language. Between Fortran and Ada it's unclear to me why C should be chosen for anything, inertia and herdthink aside.
    - TorKlingberg 11y ago
      Have you used Fortran or Ada?
      - tormeh 11y ago
        Have used Fortran. It's pretty nice, actually. I mean, it does have unstructured programming, but its structured alternatives feel pretty natural. Fortran code, like C code, feels a bit fragile but unlike C, Fortran doesn't seem to be actively malevolent. I only know Ada by its (excellent) reputation. EDIT: Only true if you use the implicit-none flag when compiling Fortran.
    - vezzy-fnord 11y ago
      Because it intersects with most of what you're doing. Why is that process supervisor I'm using crashing? Oh, it's still using select(2) instead of a modern I/O multiplexing mechanism, and exceeding its FD_SETSIZE limit. What do all these calls mean in my tracing output? All the infrastructure you're using goes through C/POSIX in one way or another. When things go haywire, you can only get by fixing it on the higher levels or just blindly restarting for so long.
marco2357 11y ago
Performance is of course lower. But it's impossible to put a number on it. Certainly native calls (printf, scanf, fopen, fread) add a lot of overhead. Also whenever the C memory layout has to be used, performance suffers (e.g. complex pointer arithmetic). But the approach is to get the correct translation first, and then - if needed - bottlenecks can be removed manually. This should lead to a better migration/upgrading experience.
acbart 11y ago
Most universities still teach a mandatory OS course where students build their own shell in C. Just because we start people off in block-based languages and python doesn't mean that Computer Scientists don't get the full tour of languages.

coldtea 11y ago

>Why do young students no longer learn C? Who said they don't? This project is about porting existing stuff, for interoperability, etc. Not as a way to "avoid learning C". >Don't you want to be closer to the underlying OS? No, why would I want to do that unless I have a specific need for that?

vezzy-fnord 11y ago
No, why would I want to do that unless I have a specific need for that? At least if you're using a Unix-like system, then understanding POSIX is essential for knowing how things work starting on an intermediate level.
- tormeh 11y ago
  And why would I want to understand how things work down in the OS? Anyway, C is a horrible language. Between Fortran and Ada it's unclear to me why C should be chosen for anything, inertia and herdthink aside.
  - TorKlingberg 11y ago
    Have you used Fortran or Ada?
    - tormeh 11y ago
      Have used Fortran. It's pretty nice, actually. I mean, it does have unstructured programming, but its structured alternatives feel pretty natural. Fortran code, like C code, feels a bit fragile but unlike C, Fortran doesn't seem to be actively malevolent. I only know Ada by its (excellent) reputation. EDIT: Only true if you use the implicit-none flag when compiling Fortran.
  - vezzy-fnord 11y ago
    Because it intersects with most of what you're doing. Why is that process supervisor I'm using crashing? Oh, it's still using select(2) instead of a modern I/O multiplexing mechanism, and exceeding its FD_SETSIZE limit. What do all these calls mean in my tracing output? All the infrastructure you're using goes through C/POSIX in one way or another. When things go haywire, you can only get by fixing it on the higher levels or just blindly restarting for so long.

marco2357 11y ago

Performance is of course lower. But it's impossible to put a number on it. Certainly native calls (printf, scanf, fopen, fread) add a lot of overhead. Also whenever the C memory layout has to be used, performance suffers (e.g. complex pointer arithmetic). But the approach is to get the correct translation first, and then - if needed - bottlenecks can be removed manually. This should lead to a better migration/upgrading experience.

acbart 11y ago

Most universities still teach a mandatory OS course where students build their own shell in C. Just because we start people off in block-based languages and python doesn't mean that Computer Scientists don't get the full tour of languages.