3 ms·

Requiring things be defined in the right order is a bit annoying, as the computer can surely figure it out... but a lot of us are working with really large code

by saurik 3y ago

Requiring things be defined in the right order is a bit annoying, as the computer can surely figure it out... but a lot of us are working with really large codebases that are very slow to compile and alleviating the compiler from having to know the entire file--or in some cases entire modules... madness!!--before being able to understand what any of it means really helps.

shadowgovt 3y ago
If compilation speed is an issue, you're already sunk in C and C++ because the #include evaluation rules leave very little room to optimize the massive redundancy of computing headers over and over (and every header includes all its headers, and etc).
- uecker 3y ago
  In C headers are not a problem. They are simple and effective. C++ made the mistake of putting implementations into headers for generic programming.
  - TazeTSchnitzel 3y ago
    C can have the same problem, it has inline functions.
    - uecker 3y ago
      Sure, you could also put a lot of complicated macros into headers. But in practice it is not a problem because this is not how you would do it in C. But in C++ you put the definition of a class into the header. Also templates basically have to exist in headers. So it is normal for C++ code to have a lot of code in headers.
akkartik 3y ago
You're basically saying pooling code between a large group might be worthwhile even if it requires you to take on a lot of book-keeping the computer could in principle help with. I don't think I've seen anyone else put it this way before. Then again, we have so much compute going to LLMs lately, I wonder if we need to revisit our assumptions about how much hardware we have available for compilation. What might a language look like with the assumption we can spread LLM-training levels of hardware among everyone working on a large codebase? Or a compiler that can consult some sort of ML-based cache for reordering decisions? There's a new space of options opening up here.

by saurik 3y ago

shadowgovt 3y ago

If compilation speed is an issue, you're already sunk in C and C++ because the #include evaluation rules leave very little room to optimize the massive redundancy of computing headers over and over (and every header includes all its headers, and etc).

uecker 3y ago
In C headers are not a problem. They are simple and effective. C++ made the mistake of putting implementations into headers for generic programming.
- TazeTSchnitzel 3y ago
  C can have the same problem, it has inline functions.
  - uecker 3y ago
    Sure, you could also put a lot of complicated macros into headers. But in practice it is not a problem because this is not how you would do it in C. But in C++ you put the definition of a class into the header. Also templates basically have to exist in headers. So it is normal for C++ code to have a lot of code in headers.

akkartik 3y ago

You're basically saying pooling code between a large group might be worthwhile even if it requires you to take on a lot of book-keeping the computer could in principle help with. I don't think I've seen anyone else put it this way before. Then again, we have so much compute going to LLMs lately, I wonder if we need to revisit our assumptions about how much hardware we have available for compilation. What might a language look like with the assumption we can spread LLM-training levels of hardware among everyone working on a large codebase? Or a compiler that can consult some sort of ML-based cache for reordering decisions? There's a new space of options opening up here.