> there is no feasible way to interpret TextMate grammars in the browser even today
That doesn't sound right... but then again I don't know enough about TextMate grammars to argue.
That doesn't sound right... but then again I don't know enough about TextMate grammars to argue.
- the only way to interpret the grammars and get anywhere near original fidelity is to use the exact same regular expression library (with its custom syntax constructs) in VSCode, our runtime is node.js and we can use a node native module that exposes the library to JavaScript
- in the Monaco Editor, we are constrained to a browser environment where we cannot do anything similar
- we have experimented with Emscripten to compile the C library to asm.js, but performance was very poor even in Firefox (10x slower) and extremely poor in Chrome (100x slower).
- we can revisit this once WebAssembly gets traction in the major browsers, but we will still need to consider the browser matrix we support. i.e. if we support IE11 and only Edge will add WebAssembly support, what will the experience be in IE11, etc.
The article says "It was shipped in the form of the Monaco Editor in various Microsoft projects, including Internet Explorer's F12 tools"; presumably some of those projects also embed it into webpages.
Maybe more things, I stopped reading the docs at that point to comment here. They have other features absent from JS that can be more or less polyfilled, like possessive quantifiers and sticky matching (they do it with an escape sequence, though, so it can only be polyfilled using this trick[1] if the escape character applies to the whole regexp rather than part of it).
[0] https://github.com/kkos/oniguruma/blob/1983356862bc3ff795d77...
I'm surprised I've never seen that typo for regex before. It's wonderful.
Can anyone explain why this is the case? It's not only in VSCode, I remember seeing something about TextMate grammars also in other editors.
It's harder than it sounds if you want to support many languages. The Sublime syntaxes repo I use has 34,000 lines of grammars whereas my engine is only 3000 lines of code. If you count all the tmLanguage files for nice languages available online it's probably hundreds of thousands of lines, and that's in a pretty dense format. The whole point of using tmLanguage files is that people don't care about how fast other languages are if there is no highlighting for their language. I could get way better performance by rewriting all those grammars using compiled parsers in Rust (like Xi has as an option https://github.com/google/xi-editor) but it would take an absurd amount of effort.
Why don't we use other text editors grammars that are simpler/quicker to parse in JS? I have no idea on the technicalities, but for instance, Vim or Emacs grammars instead?
My experience is that most syntax highlighters and their definition formats (Scintilla, nano, almost anything that's based on JavaScript) are very limited/naïve compared to TextMate's. It doesn't have to be that way -- TM can certainly be improved upon -- but it is.
Maybe they meant that browsers don't usually have access to the file system, but that's changing and also not applicable since they're using Electron and have NodeJS at their disposal.