4 ms·

You can't possibly be serious. As things stand, even just redefining a struct field requires restarting the interpreter, which forces you to wait ~10-30 seconds

by saiojd 6y ago

You can't possibly be serious. As things stand, even just redefining a struct field requires restarting the interpreter, which forces you to wait ~10-30 seconds for everything to compile, over and over again. Maybe you only use Julia for small scripts, and can afford to never restart the interpreter?

the-smug-one 6y ago
Dang, why can Common Lisp do this so well and Julia so poorly?
- eigenspace 6y ago
  The assumptions our compiler is able to make about types never changing (and a few other restrictions) allows for a lot of optimizations in julia that are not possible in Common Lisp. Julia's compiler is able to do a few things significantly more aggressively than CL. That said, there is some very interesting work happening on getting around these restrictions. There was a PR from Tim Holy a while ago that could have allowed it, but there were some problems with the PR, and there were also some associated costs that were deemed too steep to pay. That said, there's other great work on other ways around this. For instance, you can dynamically redefine structs all you want in Pluto.jl notebooks and there's no performance penalty! This is something that kinda just fell out as a natural consequence of it's reactive design.
fishmaster 6y ago
> even just redefining a struct field requires restarting the interpreter It really doesn't if you use a module.
- saiojd 6y ago
  I mean, I still need to recompile the module no? Or do you split your project into several small modules to avoid this? (I've avoided this so far as I found the module system a bit tedious tbh, as it requires to explicitly list everything you need to export, as well as manually import stuff from the parent module).
  - fishmaster 6y ago
    Usually as long as I develop I have structs that I change inside a small module, then I can recompile just the module and access the new struct, e.g. for neural networks. It's not perfect but it's something.
    - saiojd 6y ago
      Useful trick, I'll try that, thanks.

by saiojd 6y ago

the-smug-one 6y ago

Dang, why can Common Lisp do this so well and Julia so poorly?

eigenspace 6y ago
The assumptions our compiler is able to make about types never changing (and a few other restrictions) allows for a lot of optimizations in julia that are not possible in Common Lisp. Julia's compiler is able to do a few things significantly more aggressively than CL. That said, there is some very interesting work happening on getting around these restrictions. There was a PR from Tim Holy a while ago that could have allowed it, but there were some problems with the PR, and there were also some associated costs that were deemed too steep to pay. That said, there's other great work on other ways around this. For instance, you can dynamically redefine structs all you want in Pluto.jl notebooks and there's no performance penalty! This is something that kinda just fell out as a natural consequence of it's reactive design.

fishmaster 6y ago

> even just redefining a struct field requires restarting the interpreter It really doesn't if you use a module.

saiojd 6y ago
I mean, I still need to recompile the module no? Or do you split your project into several small modules to avoid this? (I've avoided this so far as I found the module system a bit tedious tbh, as it requires to explicitly list everything you need to export, as well as manually import stuff from the parent module).
- fishmaster 6y ago
  Usually as long as I develop I have structs that I change inside a small module, then I can recompile just the module and access the new struct, e.g. for neural networks. It's not perfect but it's something.
  - saiojd 6y ago
    Useful trick, I'll try that, thanks.