ML as the ES4 spec meta-language
Brendan Eich scripsit:
We seem to have chosen ML (OCaml with call/cc, probably) as the meta- language for the ES4 spec.
That's why it's called ML (MetaLanguage); ML began as a metalanguage. I wish you were using SML instead of OCaml, but I suppose I can learn.
On Oct 20, 2006, at 4:14 PM, John Cowan wrote:
Brendan Eich scripsit:
We seem to have chosen ML (OCaml with call/cc, probably) as the meta- language for the ES4 spec.
That's why it's called ML (MetaLanguage); ML began as a metalanguage.
Yeah, we know.
I wish you were using SML instead of OCaml, but I suppose I can learn.
It's not hard :-P.
On Oct 20, 2006, at 4:19 PM, Brendan Eich wrote:
On Oct 20, 2006, at 4:14 PM, John Cowan wrote:
Brendan Eich scripsit:
We seem to have chosen ML (OCaml with call/cc, probably) as the
meta- language for the ES4 spec.That's why it's called ML (MetaLanguage); ML began as a metalanguage.
Yeah, we know.
I wish you were using SML instead of OCaml, but I suppose I can
learn.It's not hard :-P.
I should add, more constructively, that we are not using the
Objective part of OCaml; in fact we are trying to use a subset that
will be easy for SML folks to read and write. But we need the call/
cc patch to OCaml, because we do not want to model an ES4 stack
machine or continuation machine. We want the meta-language to
support call/cc directly.
This is a pragmatic decision, and there are other ways to skin the
cat for sure, but they tend to taint the entire reference
implementation and make it obscure. We believe we can keep this call/
cc monster in a box, so that it does not taint the spec and break
abstraction everywhere. It is needed only for yield and perhaps a
few other hard cases.
We seem to have chosen ML (OCaml with call/cc, probably) as the meta- language for the ES4 spec. This is hot of the presses, but it looks
like the right choice, and any change that moves away from it will
take unlikely effort and a better candidate language. We were faced
with the arduous task of inventing our own sound meta-language, and
it started looking like ML with customizations.This means we will have a reference implementation, with all the
software engineering overhead that implies. But it will be an
implementation whose goal is clarity and soundness, not space or time
performance. And with some work, as Cormac Flanagan points out, the
reference code (or probably a subset of it) could be used with Coq to
do automated proofs.We will make the reference implementation available in due course, as
open source. We will welcome contributors (Hi, Nicolas! ;-)./be
Sounds like a good choice ;)
Keeping the code pure Caml (without the Object system) is also a good thing, since although OCaml object system is incredibily powerful, it's also quite difficult to master.
Hope to see some code available soon for review.
Best,
We seem to have chosen ML (OCaml with call/cc, probably) as the meta- language for the ES4 spec. This is hot of the presses, but it looks
like the right choice, and any change that moves away from it will
take unlikely effort and a better candidate language. We were faced
with the arduous task of inventing our own sound meta-language, and
it started looking like ML with customizations.
This means we will have a reference implementation, with all the
software engineering overhead that implies. But it will be an
implementation whose goal is clarity and soundness, not space or time
performance. And with some work, as Cormac Flanagan points out, the
reference code (or probably a subset of it) could be used with Coq to
do automated proofs.
We will make the reference implementation available in due course, as
open source. We will welcome contributors (Hi, Nicolas! ;-).