On Oct 27, 2011, at 4:40 AM, Axel Rauschmayer wrote: >>> +1. Where the spec is already almost pseudo-code, its readability would >>> improve if it was, in fact, pseudo-code. But would an extra interpreter be >>> needed or couldn’t one just implement the ES-262 constructs (execution >>> contexts etc.) in an existing language (Python, Rust, Scheme, Smalltalk, >>> etc.)? >> Why choosing a completely different language? Why not ECMAScript 5.1? > > Right, I had forgotten about ECMAScript itself.
I would do it in ES5, or not at all. There is absolutely no need for any other language. Always eat your own dogfood! > >> It will be one less language to learn as people who read the ES6 spec are >> very likely to be familiar with ES5.1. I personnally wouldn't feel >> comfortable reading a spec in any of the 4 languages you cited. >> Or maybe define the couple of things that can't be fully implemented in >> ES5.1 (proxies, private names) and use ES5.1 + these construct to define ES6. > > > I don’t think you need these constructs at the meta-level to implement them > at the object level. However, I would in general be in favor of ES6, because > it would help with implementing types (at the very least, subtyping would be > easier via <| ). There would be no issues here. We aren't talking about a metacircular interpreter, but a direct line-by-line translation of the spec. algorithms. An ES6 objects would not be directly represented by a single ES5 object but instead by a ES5 based data structure that implemented the object semantics specified by ES6. ES5 is Turning-compete. Anything the spec. describes can be implemented in it. Allen _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
