[userbinator]

IMHO writing a compiler for a high-level language, in an even higher level language, somehow feels a bit "anachronistic" (for lack of better word).

[retrac]

Most of the current major C implementations are written in C++.

[WalterBright]

ImportC is written in D.

[userbinator]

That's unfortunate.

[golergka]

Weren't a lot of functional languages, like ML and it's descendants, created specifically to write parsers and compilers?

[peterfirefly]

No. ML was the meta language for a theorem prover (LCF).

https://en.wikipedia.org/wiki/Logic_for_Computable_Functions

[JonChesterfield]

I've seen it claimed that ML was originally written, in lisp, in order to have a better language to write compilers in.

[lispm]

ML was written as the language used by the theorem prover LCF. It was written in Lisp.

[JonChesterfield]

I didn't know that link, searches seem to confirm. Thank you.

The LCF style provers rely on the host language type system. A theorem instance can only be created by the trusted kernel. Lisp doesn't obviously lend itself to that - you could represent the proof, but I'm not clear how you'd prevent forging one.

[avgcorrection]

For what reason?

[userbinator]

It's backwards. Writing a C compiler in C or Asm makes sense, a Python compiler in C also does, but a C compiler in Python is an odd inversion of abstraction.

[avgcorrection]

I guess this harkens back to the days when you had to write a compiler in a low-level language because that’s all that the platform that you are targeting supports. Then it sounds weird to talk about writing a compiler in a high-level language in order to target a low-level one, because surely these high-level languages are more platform-dependent than the blessed (guaranteed on the platform) low-level one.

But these days we can access dozens of languages on many platforms. And we can use high-level languages that are good for writing compilers—languages with good string types and algebraic data types—instead of being limited to awfully imperative/procedural ones.

In other words: your perspective sounds way more anachronistic.

[Jtsummers]

Why? The objective is to translate code in one language (C) to another (machine code or assembly or perhaps an intermediate representation). Why does it make sense to use C for that task and not Python or some other language? It's not like C provides facilities that specifically enable compiler writing or text parsing for itself that other languages are lacking.