Quarto development notes – Dev notes for Quarto

Span vs Link syntax in LR(1) parsers?

syntax

We need to add support for the following two syntaxes, where {ATTR} is one of {language}, {=raw-format}, {#id .class key=value}, {ATTR} is optional:

Syntax errors are Good, Actually

syntax

I consider the following sentence in the CommonMark spec to be a fatal flaw in its design:

A stand-alone surface syntax definition for Quarto

syntax

Our current reader is too slow, buggy, and hard to extend. If we commit to maintaining our own code path that translates Markdown to Pandoc’s AST, we get performance and we…

A smaller win than expected, and some ideas.

performance

lua

The change in commit 0f38bf1 merged a filter but produced smaller wins than I expected.

strange behavior with `projectMetadataForInputFile`

performance

I identified in a profile that projectMetadataForInputFile was taking a relatively long time.

More TS attempts

performance

TypeScript

For these measurements, I’m using a machine where quarto render on quarto-web takes about 240s to render on 359 files.

Lua win: remove `normalize-3`

performance

lua

Up to commit ca05876, Quarto had a three-stage filter for parsing custom AST nodes. The last stage existed to fix a bug, but turned out to be quite onerous in terms of…

`cloneDeep` avoidance

performance

TypeScript

Logging an idea for future use: we need to avoid cloneDeeping large structures. It has caused bugs in the past and is the source of performance issues.

Caching and TS profiling observations

performance

TypeScript

With a project cache available, we can start to use it. But where? I’ve already implemented caching for the SCSS variable analysis code, which takes about 0.5s seconds per…

Implementing a general-purpose project cache

performance

TypeScript

I’ve implemented a disk cache and started using it on some of our slow, stable computations (such as the analysis of SCSS files).

Hashing Performance

performance

TypeScript

In the course of 1.7’s perf work, we are going to introduce a number of persistent caches for Quarto projects. This will require knowing which hashing functions perform well…

An early win for `jog` in scoped resolution

performance

lua

A win from using jog for one of our filters: