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Compilers are their own beast — I wouldn't put them with systems code. They're pretty different from an OS, BLAS, machine learning kernel, game engine, network

Compilers are their own beast — I wouldn't put them with systems code. They're pretty different from an OS, BLAS, machine learning kernel, game engine, network stack, database or what have you. There's not as much buffer management, speed and memory aren't usually as critical, you don't make direct syscalls, many structures are graphs rather than arrays, etc. They often aren't even multithreaded. It's also popular to write compilers in distinctly non-"systems-y" languages, most notably Standard ML but also eg Haskell, and lots of languages are self-hosted.

travisgriggs 4y ago
I think compilers are a strong sub field of meta programming. I see meta programming as anything that deals directly or indirectly with ASTs. Compilers (er parsers and linkers) make ASTs and transform them. Refactoring engines (should) work with them. Sadly, I’m not sure what language I’d recommend as ideal for this (meta programming) now days. I think it’s zen cool when a language like Lisp or Zig or Elixir slides sideways in and out of meta programming, but that doesn’t mean they have good ASTs to work with, or that they’re ideal as a pseudo language to manipulate them. It should be something that is both not too complex, but also not so zen abstract that you have to bootstrap meaningful things endlessly. I personally liked the Smalltalk AST. But I couldn’t speak to its pedagogical or industry value as a meta programming environment.
- eru 4y ago
  Are you talking about the tools that eg Lisp has to manipulate arbitrary ASTs, or are you talking about the AST required to represent Lisp code? Racket (a Lisp) and ML-family languages like Haskell are really good at manipulating arbitrary ASTs and similar structures. ML was even invented to do exactly that, the letters stand for meta-language. I do agree that the structures you need to represent Haskell would be rather complicated: Haskell is a rather complex language after all. I'm not sure what you mean by having to bootstrap meaningful things endlessly? I can understand that eg C is pretty limited, so you have to put in lots of effort to bootstrap to something meaningfully. But most higher level languages would be doing just fine. And you can also use libraries: Eg no need to write your own parser from scratch, if you can just use a parser combinator library like parsec. Also no need for a beginner to write native code generation from scratch: just use a library to interface with llvm.
eru 4y ago
Yes, compilers at most have a bit of overlap with systems programming, but don't really have that much to do with it. The overlap comes from two places: (1) If you want to generate fast code, you need to know how your target works. That's pretty low level, and could be considered systems programming? (2) Many people want compilers themselves to run fast. Here again, the way to get the most speed out of your programs is often to go low level (and again we could see low level as a synonym for systems programming?)
pjmlp 4y ago
At which level would you place the OS linker required by the compiler? Given that Bastion written in XNA, and widely successful, then from your list C# is a system programming language. Or maybe Java is one, given Minesweeper and bare metal deployments like those sold by PTC and Aicas.
amelius 4y ago
> Compilers are their own beast — I wouldn't put them with systems code. Unless your systems code runs using a JIT.

travisgriggs 4y ago

I think compilers are a strong sub field of meta programming. I see meta programming as anything that deals directly or indirectly with ASTs. Compilers (er parsers and linkers) make ASTs and transform them. Refactoring engines (should) work with them. Sadly, I’m not sure what language I’d recommend as ideal for this (meta programming) now days. I think it’s zen cool when a language like Lisp or Zig or Elixir slides sideways in and out of meta programming, but that doesn’t mean they have good ASTs to work with, or that they’re ideal as a pseudo language to manipulate them. It should be something that is both not too complex, but also not so zen abstract that you have to bootstrap meaningful things endlessly. I personally liked the Smalltalk AST. But I couldn’t speak to its pedagogical or industry value as a meta programming environment.

eru 4y ago
Are you talking about the tools that eg Lisp has to manipulate arbitrary ASTs, or are you talking about the AST required to represent Lisp code? Racket (a Lisp) and ML-family languages like Haskell are really good at manipulating arbitrary ASTs and similar structures. ML was even invented to do exactly that, the letters stand for meta-language. I do agree that the structures you need to represent Haskell would be rather complicated: Haskell is a rather complex language after all. I'm not sure what you mean by having to bootstrap meaningful things endlessly? I can understand that eg C is pretty limited, so you have to put in lots of effort to bootstrap to something meaningfully. But most higher level languages would be doing just fine. And you can also use libraries: Eg no need to write your own parser from scratch, if you can just use a parser combinator library like parsec. Also no need for a beginner to write native code generation from scratch: just use a library to interface with llvm.

eru 4y ago

Yes, compilers at most have a bit of overlap with systems programming, but don't really have that much to do with it. The overlap comes from two places: (1) If you want to generate fast code, you need to know how your target works. That's pretty low level, and could be considered systems programming? (2) Many people want compilers themselves to run fast. Here again, the way to get the most speed out of your programs is often to go low level (and again we could see low level as a synonym for systems programming?)

pjmlp 4y ago

At which level would you place the OS linker required by the compiler? Given that Bastion written in XNA, and widely successful, then from your list C# is a system programming language. Or maybe Java is one, given Minesweeper and bare metal deployments like those sold by PTC and Aicas.

amelius 4y ago

> Compilers are their own beast — I wouldn't put them with systems code. Unless your systems code runs using a JIT.