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Comment by kovrik | Hacker News Reader

Thank you so much for the book, please, continue!

I am currently working on Scheme R5RS implementation in Java. It is a hobby project, but I'm really enjoying it. It is somewhat enlightening.

Look forward to reading the Optimization chapter: I couldn't find much useful and practical info on that. I think it is quite easy to implement your interpreter, but it is really difficult (at least for me) to make it fast.

Can anyone recommend any articles or books with common optimization tricks and techniques?

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> Thank you so much for the book, please, continue!

I will!

> Look forward to reading the Optimization chapter: I couldn't find much useful and practical info on that.

There's not too much depth in that particular chapter. The whole second part is really about implementing an interpreter (fairly) efficiently in C. As you probably know, you have to think about performance at every level—your object model, bytecode format, hash table implementation, etc.

If you'd like a sneak peek, the code for the entire book is actually done already (!). You can see which snippets go into each chapter cloning the repo[1] then running:

    make chapters
    make c_chapters
    make diffs

Then take a look in build/diffs.

There are a ton of optimization tricks that are specific to Scheme and Lisps and a lot of literature behind them. Macros and eval make it a lot harder. It's pretty dense, but I liked "Lisp in Small Pieces" a lot.

[1]: https://github.com/munificent/craftinginterpreters

For making an efficient Scheme implementation: most everything written by R. Kent Dybvig or his students. I'd start with his PHd thesis (Three Implementation Models for Scheme, specifically the stack-based part).

http://www.cs.indiana.edu/~dyb/

(See also Lua's upvalues for a way to optimize closure variable access that's a bit simpler than his display closures).

> See also Lua's upvalues for a way to optimize closure variable access

Yes! In fact, that's how the C version of the interpreter in my book implements closures. It's pretty brilliant. <3 those Lua folks.

Will you cover anything about LuaJIT's "NaN-coding"?

Or perhaps do you have a link about how it works?

Yes, we'll do NaN-tagged values in the last chapter on optimization.

Lisp In Small Pieces by Christian Queinnec

I'm trying to bootstrap a forth and a scheme but i'm still at the thinking phase right now.

Take a look at Nils Holm's http://www.lulu.com/shop/nils-m-holm/lightweight-compiler-te...

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