Rich Harris joins Vercel to work on Svelte full time

I read it as: Svelte is faster in theory, but since people write bad Svelte code, it is slower than the React code the same developers would write.

My interpretation is that this can be attributed to either svelte being hard to write, or people being used to React. Both of which are a challenge to companies looking to switch to Svelte.

Mozilla Xulrunner and Rhino (a JavaScript interpreter implemented in Java) used to support E4X: ECMAScript for XML, the ISO/IEC standard 22537:2006, and it was removed in 2014.

https://en.wikipedia.org/wiki/ECMAScript_for_XML

>ECMAScript for XML (E4X) is the standard ISO/IEC 22537:2006 programming language extension that adds native XML support to ECMAScript (which includes ActionScript, JavaScript, and JScript). The goal is to provide an alternative to DOM interfaces that uses a simpler syntax for accessing XML documents. It also offers a new way of making XML visible. Before the release of E4X, XML was always accessed at an object level. E4X instead treats XML as a primitive (like characters, integers, and booleans). This implies faster access, better support, and acceptance as a building block (data structure) of a program.

>E4X is standardized by Ecma International in the ECMA-357 standard. The first edition was published in June 2004, the second edition in December 2005.

>The E4X standard was deprecated by the Mozilla Foundation in 2014.

https://bugzilla.mozilla.org/show_bug.cgi?id=695577#c1

>Mark S. Miller, 10 years ago

>"use strict" is currently our one real opt-in boundary for simplifying the language and reducing threats by dropping legacy complexity that is generally no longer needed. As Brendan said somewhere "E4X is crazyland", and FF's implementation of E4X deviates from the spec in ways that are not written down anywhere. Until we encountered this issues, it looked like SES could bring ocap security to ES5.1 without doing an accurate lex or parse. With this restriction, we could regain this economy.

>Besides, no one wants to upgrade the E4X semantics to be compatible with ES5 or ES.next, so this seems a good time to impose this opt-in restriction.

https://news.ycombinator.com/item?id=8266648

>bastawhiz on Sept 4, 2014 | parent | context | un‑favorite | on: JSX: XML-like syntax extension to ECMAScript – Dra...

>So..uh...this was a thing. And nobody wanted it. So it was deprecated and killed. See the "Prior Art" section at the bottom of the page.

http://en.wikipedia.org/wiki/ECMAScript_for_XML

>Brendan Eich was quoted as saying something along the lines of "E4X is crazyland". Parsing it is hard as hell to do right. Think of all the tooling that's out there for JavaScript right now that will either a.) not support JSX code or b.) bloat up beyond belief as it takes into account the suddenly absurd requirements necessary to deal with a similar-but-not-quite-XML-or-even-HTML-for-that-matter syntax. Oh, you want to lint that JavaScript? Bless your heart! You want to add syntax highlighting? Love will find a way. You want to use other static analysis tools, sweet.js macros, or anything else non-trivial? How cute!

>So essentially, it's a great way for Facebook to push React.js without making React.js a standard.

https://stackoverflow.com/questions/33642820/why-was-e4x-dep...

>It was deprecated and removed from the only browser that ever supported it because it was a poorly implemented language feature that was causing all sorts of problems.

>As Brendan said somewhere "E4X is crazyland", and FF's implementation of E4X deviates from the spec in ways that are not written down anywhere. — Mark S. Miller

>The only way for it to come back would be via a new edition of ECMA-357, which Adobe and Mozilla were going to work on. Until then, it's out. — Brendan Eich

>The idea behind it wasn't bad, but the way it was integrated into the language was. SpiderMonkey was the only JS engine that ever implemented it, and there were endless problems caused by that and severe complications of the engine's implementation required for this support. — Till Schneidereit

100% - Common guys we are programmers in a field that is know for changing consistently (probably a lot faster than other careers). If you see learning new "syntax" for the basics (loops,conditionals etc) then you going to have problems down the road. Weather you use svelte, or some other new tech. If you really never want to learn another syntax.. learn LISP and be done with it.

You are a programmer, you will need to learn new syntax a few times in your career.

If some of the "biggest" complaints are "oh no I have to learn how to write for-loops again" - I guess svelte is doing the important stuff right.

Wayyyy back in the day(ok not that long ago - 80/90's) when I was learning a new lang (Pascal,C, C++) I used to tell myself If I can get an working example of:

1) "user-input (readline,scanf etc)"

2) "printing input/output"

3) "calling functions/procedures"

4) "Do the loops + conditionals"

5) "file I/O"

6) "Memory schematics"

You basically mastered the "building blocks/mrk(min-req-knowledge)" of the new lang and like maths you only need now practice or a good project.

TL;DR If you are a professional-career-programmer, learning "new syntax (we used to call them keywords)" is a requirement.

Much of this I would have expected, but this was less obvious:

> There are major tradeoffs made by doing things at compile time. Things that are easy in React at runtime turn out to be surprisingly difficult in Svelte

What are some examples of this?

100% agree !