IT IS ALIVE! (kinda sorta)

[nikodemus]

Houston, we have self hosting! (PR #735) 🚀

I just now got the following chain completed:

1. Compile the compiler with itself, running under the bootstrap evaluator.
2. Compile the compiler with a compiled version of itself.
3. Use that compiler to compile a hello-world.
4. Run that and watch it print: "Hello world!"

(This was the first time that step 2 above completed, so I wasn't going to try anything more challenging then a hello world the first time...)

There was just a bit of cheating involved: System#command: is not implemented yet in the self-hosted system, so it could not actually run the C-compiler itself, but I did that manually for each step.

HUZZAH! I'm going to pour myself a whisky now and go sip on it on the balcony. 🌞

[nikodemus]

NB: The compiler currently generates ridiculously bad code, and heap allocates all activation records, making it almost 7 x slower than the bootstrap evaluator... but that's all fixable in due course!

[nikodemus]

Huh, at least half of that slowness was actually due to target Dictionary currently doing a linear search on every access - obvious in retrospect.

PR #763 replaced one use of Dictionary by storing a reference in object instead, and cut down the self-compile time by ~50%.

There's another major use of Dictionary in the compiler that's not as easy to get rid of - I guess I'll have to bite the bullet and do hash-tables. (I've written too many hash-tables in my life already...)