Inline ----- Isiah Meadows [email protected]
Looking for web consulting? Or a new website? Send me an email and we can get started. www.isiahmeadows.com On Sat, Jan 13, 2018 at 9:54 AM, Claude Pache <[email protected]> wrote: > > > Le 12 janv. 2018 à 22:09, Isiah Meadows <[email protected]> a écrit : > > I know this is probably bad timing (considering [this PR][1] and the > fallout that followed), but I was thinking that it'd be nice if we > could insert a `[no LineTerminator here]` clause in a few places, to > remove some of the ASI hazards for those going semicolon-free, along > with some extras for consistency: > > - Before the `[` in the second rule of [`MemberExpression`][2] and the > fourth rule of [`CallExpression`][3] > - Before `Arguments` in the last rule of [`MemberExpression`][2], the > third and sixth rule of [`CallExpression`][3], and > [`CoverCallExpressionAndAsyncArrowHead`][4] > - Before the `(` in [`FunctionDeclaration`][5], > [`FunctionExpression`][6], the first, fourth, and fifth rule of > [`MethodDefinition`][7], [`GeneratorMethod`][8], both rules in > [`GeneratorDeclaration`][9], and [`GeneratorFunction`][10] > > One of the practical effects would be this: this source (taken from the > spec): > > ```js > a = b + c > (d + e).print() > ``` > > is currently interpreted as: > > ```js > a = b + c(d + e).print(); > ``` > > but would, with this proposal, be interpreted as this, which is a > *lot* more intuitive with what people would expect: > > ```js > a = b + c; > (d + e).print(); > ``` > > I know there's risk of web compat concerns, but I doubt they'd be > significant for anything that's not minified via the Closure Compiler > (which limits line length by default for reasons of old IE). Also, for > most non-ASI people, they probably just forgot a semicolon anyways, > and [here][11] is a concrete example of this, where ESLint was fixing > a linter violation incorrectly because it wasn't reading it as you'd > expect. > > > I think that the BC incompatibility issue is more than just a risk. I recall > (but I couldn’t find it) that someone gave the example of some library that > reads better when used as: > > ```js > foo > (bar) > (baz) > ``` Do you have any ideas where I could look to potentially find it? I've never seen *that* kind of DSL before, and that's an interesting use case I haven't considered. > > Also, cases you have forgotten, and where I *really* wish there be a [NLTH] > rule, are *after* some contextual keywords that are used in prefix position, > namely `get`, `set` and `static` (as it is already the case for `async`). > See > https://tc39.github.io/proposal-class-fields/#sec-asi-hazards-in-class-bodies > for context. This is not only to satisfy my coding style, but also to ensure > consistency when further contextual keywords will be added in the top level > of class bodies, since those future keyword will require such a [NLTH] rule > in order to be compatible with previously written field declarations that > take advantage ASI. I thought about those, and I would ideally like those to be similarly chnaged, but I decided against including them in this particular proposal, since I wanted to focus on `[` and `(`, and I wasn't as keen on web compat (considering it's actually a style many people prefer). > > —Claude > > > > > [1]: https://github.com/tc39/ecma262/pull/1062 > [2]: https://tc39.github.io/ecma262/#prod-MemberExpression > [3]: https://tc39.github.io/ecma262/#prod-CallExpression > [4]: > https://tc39.github.io/ecma262/#prod-CoverCallExpressionAndAsyncArrowHead > [5]: https://tc39.github.io/ecma262/#prod-FunctionDeclaration > [6]: https://tc39.github.io/ecma262/#prod-FunctionExpression > [7]: https://tc39.github.io/ecma262/#prod-MethodDefinition > [8]: https://tc39.github.io/ecma262/#prod-GeneratorMethod > [9]: https://tc39.github.io/ecma262/#prod-GeneratorDeclaration > [10]: https://tc39.github.io/ecma262/#prod-GeneratorExpression > [11]: https://github.com/eslint/eslint/issues/7787 > > ----- > > Isiah Meadows > [email protected] > > Looking for web consulting? Or a new website? > Send me an email and we can get started. > www.isiahmeadows.com > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss > > _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
