Hi Philip, On Mon, 23 Aug 2021 at 13:30, Philip McGrath <phi...@philipmcgrath.com> wrote: > On 8/23/21 11:38 AM, zimoun wrote: >> The bootstrap path of Racket in Guix is not clear to me. I miss if a >> Racket interpreter or compiler in its binary format is used (as >> Haskell for instance) or if all is compiled from source using tools >> already bootstrapped. Anyway, I miss what you would like bootstrap? >> If you mean a trusted seed in order to start a package collection, you >> could use the current Guix binaires---as a starting point. > > I wrote a long comment at the top of gnu/packages/racket.scm that > explains the current state of affairs. (For anyone unfamiliar with the > Guix source tree: > <https://git.savannah.gnu.org/cgit/guix.git/tree/gnu/packages/racket.scm>)
Oh sorry! I did incorrectly my homework… although I remember the discussion with Ludo when you submitted the patch set. :-) > In brief, Racket is bootstrapped from source using only a C > compiler---including bootstrapping Racket's fork of Chez Scheme without > an existing Chez Scheme compiler---with one exception: the "expander" > subsystem (which implements the reader, module system, and macro > expander) is implemented in Racket, and the older C implementation was > completely replaced as of Racket 7.0. (One of the motivations was to fix > many problems with the old implementation.) For bootstrapping, an > intermediate representation as a "schemified" linklet is checked into > the Racket source repository. Thanks for explaining. All is clear. > This impact is mitigated because, by design, the intermediate > representation is "human-readable and -editable Scheme code". > Anecdotally, when I read diffs of changes to the Racket repository, I > sometimes read tens of lines of code before I realize that I'm looking > at the generated version of the file, not the source. So the expander is > not bootstrappable in the most rigorous sense, but it is readily auditable. > > If someone wanted to tie the knot, the task would be to use an existing > bootstappable language to write a minimal expander that can expand the > canonical Racket implementation: if your output is identical to the > checked-in generated files, you've succeeded. (Using Guile could avoid > the heavy maintenance burden of the old C expander implementation, and > indeed you could write just enough of an adapter to load the Racket > source files into Guile, which is the technique Racket uses to bootstrap > the Chez Scheme compiler.) I expect Racket would welcome a contribution > along those lines; it just hasn't been a priority for anyone yet. Guile everywhere! ;-) Thanks again the details. Cheers, simon
