Readit News logoReadit News
Posted by u/yshavit a year ago
Show HN: Jq-Like Tool for Markdowngithub.com/yshavit/mdq...
There have been a few times I wanted the ability to select some text out of a Markdown doc. For example, a GitHub CI check to ensure that PRs / issues / etc are properly formatted.

This can be done to some extent with regex, but those expressions are brittle and hard to read or edit later. mdq uses a familiar pipe syntax to navigate the Markdown in a structured way.

It's in 0.x because I don't want to fully commit to the syntax being stable, in case real-world testing shows that the syntax needs tweaking. But I think the project is in a pretty good spot overall, and would be interested in feedback!

verdverm · a year ago
> GitHub PRs are Markdown documents, and some organizations have specific templates with checklists for all reviewers to complete. Enforcing these often requires ugly regexes that are a pain to write and worse to debug

This is because GitHub is not building the features we need, instead they are putting their energy towards the AI land grab. Bitbucket, by contrast, has a feature where you can block PRs using a checkbox list outside of the description box. There are better ways to solve this first example from OP readme. Cool project, I write mainly MDX these days, would be cool to see support for that dialect

bradgessler · a year ago
Not only is GitHub focused on AI, but they’re also making their UI slower and jankier by rewriting it in React.

I feel like a “Linear for GitHub” is due.

nicce · a year ago
Is it true that it is React’s fault? Is there any other replacement for heavy user interaction, that is clearly more performative? You cannot do that on server side.
colonial · a year ago
Holy crap, is that why it's felt so syrupy recently? What was wrong with the old implementation?!
iansinnott · a year ago
Linear itself has a workflow for Github: https://linear.app/docs/github
whateveracct · a year ago
Linear? That website makes my laptop heat up like nuts.
sorrythanks · a year ago
yshavit · a year ago
The Markdown parsing library I'm using supports MDX, so it shouldn't be too difficult to come up with syntax for those components. I haven't done that yet, but mostly because I didn't want to go down that path until I knew there was interest and had a concrete use case or two to inform the query syntax.

If you want to open an enhancement request issue, I'm happy to take a look (PRs also welcome, but not required). If you're not on GitHub, let me know and we can figure out some other way to get the request tracked.

Thanks for taking a look at the project!

verdverm · a year ago
I don't write rust and already have an MDX toolbox that fits my needs. Browser, GH, and IDE search / TOC are good enough for me.

I'm currently in a phase of trying to shed tools and added complexity, rather than add them

hamandcheese · a year ago
GitHub was ignoring users needs long before the AI craze.
jvanderbot · a year ago
It's hard to remember, but as soon as gitlab showed up, GitHub went from a "maybe someday if I make it" site to a "let's just use GitHub for everything" site.

Prior to gitlab ratcheting up the usability, features, and cost effectiveness, I preferred hosted git for 99% of use cases.

echelon · a year ago
> This is because GitHub is not building the features we need, instead they are putting their energy towards the AI land grab.

You throw the ball to where it's going. Gitlab might be delivering more value in the short term, but if things wind up looking significantly different in ten years, they might be in for a world of hurt. Innovator's dilemma is real.

It's a danger to ignore the tectonic changes happening. It's also incredibly risky to lean fully in, because we're not sure where the value accrues or which systems are the most important to build. It doesn't seem like foundation models are it.

It's smart to build basic scaffolding, let the first movers make all the expensive mistakes, then integrate the winning approaches into your platform. That requires a lot of energy though.

mtndew4brkfst · a year ago
> That requires a lot of energy though.

So do the plagiarism machines!

codelion · a year ago
it's a shame when core feature development seems to lag. i've also been working w/ MDX lately & agree that support would be a great addition.
kqr · a year ago
> Bitbucket, by contrast, has a feature where you can block PRs using a checkbox list outside of the description box

I'm not sure this is better. I like the idea of the full context of the PR being available in a small set of relatively standardised fields. Smaller, non-semantic sets are easier to standardise.

verdverm · a year ago
I'm not sure how having a list of remaining tasks that can be added to adhoc and block PRs from merging is not better than check boxes in markdown description box that are little more than aesthetic...

It has saved us from self induced pain and is a great coordination point

bastardoperator · a year ago
Or maybe GitHub built these features over 10 years ago and millions upon millions of people use them daily without issue. You can literally have any semblance of what you're describing with a PR check, and that feature is also pretty old. The API is right there, you just have to use it.
lanstin · a year ago
Ironically one of the reasons markdown (and other text based file formats) were popular because you could use regular find/grep to analyze it, and version control to manage it.
zahlman · a year ago
I don't think anyone ever really expected to see widespread use of regexes to alter the structure of a Markdown document. Honestly, while something like "look for numbers and surround them with double-asterisks to put them in boldface" is feasible enough (and might even work!), I can't imagine that a lot of people would do that sort of thing very often (or want to) anyway.

If a document is supposed to have structure - even something as simple as nested lists of paragraphs - it doesn't seem realistic to expect regular text manipulation tools to do a whole lot with them. Something like "remove the second paragraph of the third entry in the fourth bullet-point list" is well beyond any sane use of any regex dialect that might be powerful enough. (Keeping in mind that traditional regexes can't balance brackets; presumably they can't properly track indentation levels either.)

See also: TOML - generally quite human-editable, but still very much structured with potentially arbitrary nesting.

kmstout · a year ago
> (Keeping in mind that traditional regexes can't balance brackets; presumably they can't properly track indentation levels either.)

You're right: Regular expressions are equivalent to finite state machines[1], which lack the infinite memory needed to handle arbitrarily nested structures [2]. If there is a depth limit, however, it is possible (but painful) to craft a regex to describe the situation. For example, suppose you have a language where angle brackets serve as grouping symbols, like parentheses usually do elsewhere [3]. Ignoring other characters, you could verify balanced brackets up to one nesting level with

  /^(<>)*$/
and two levels with

  /^(<(<[^<>]*>|[^<>])*>)*$/
Don't do this when you have better options.

---

[1] https://reindeereffect.github.io/2018/06/24/index.html

[2] As do any machines I can afford, but my money can buy a pretty good illusion.

[3] < and > are not among the typical regex metacharacters, so they make for an easier discussion.

lanstin · a year ago
I think that prospect (of programmatically structurally editing markdown files) would have made everyone burst out in laughter in 2000; if you want to programmatically alter stuff, put it into sexp's or some other syntax. SGML. Apparently human readable but really a tricky format leads to this sort of thing: https://ruudvanasseldonk.com/2023/01/11/the-yaml-document-fr...
monsieurbanana · a year ago
> because you could use regular find/grep to analyze it

They were meant to be analyzable in some ways. Count lines, extract headers, maybe sed-replace some words. But being able to operate/analyze over multiline strings was never a strong point of unix tools.

cdbattags · a year ago
Definitely, but it's neat nonetheless because more and more things are "structured Markdown" these days. Extremely useful for AI reasoning and outputs.
llm_trw · a year ago
Man if we only had some type of markdown meant for machines to understand, that was specifically designed to handle arbitrary information nesting and tagging our lives would be so much better now.

We could have called it something like extended markdown language or something and use a wicked acronym like eXMaLa for it.

Shame no such technology exists and never did.

unglaublich · a year ago
My flow is to go through the Pandoc JSON AST and then use Jq. This works for other input formats, too.
yshavit · a year ago
I'm curious how ergonomic you find that? I did look at the pandoc JSON initially, and found it fairly awkward to work with. It's a great interchange format, but doesn't seem optimized for either human interaction or scripting. (It's definitely possible to use it for scripting, it just felt cumbersome to me, personally.)
saghm · a year ago
I've never had a need for parsing markdown like this, bit I have to wonder, would it make to go through HTML instead, given that it's what markdown is designed to compile to? At that point, I'd assume there's any number of existing XML tools that work work, and my (maybe naive) assumption is that typical markdown documents would be relatively flat compared to how deeply nested "native" HTML/XML often gets, so it doesn't seem like most queries would require particularly complex XPath to be able to specify.
MathMonkeyMan · a year ago
I did this for a tool that checks relative links in markdown files, e.g. readmes in a repo.

markdown -> xhtml -> sxml -> logic (racket)

dleeftink · a year ago
Kind of aligned with this is MarkdownDB, providing an SQLite backend to your Markdown files [0]. Cool to see this, I feel the structure of .md files is not always equally respected or regarded as a data serialisation target.

[0]: https://markdowndb.com/

broodbucket · a year ago
I think you'd benefit of having some more real-world-ish examples in the README, as someone who doesn't intuit what I'd want to use this for.
yshavit · a year ago
That's a great idea, thanks! I'll do that tomorrow or so.

As a preview, two specific cases I've seen:

1) In PRs, some companies like to have semi-structured metadata, like a link to a related ticket under a heading "Ticket". In mdq, you could find that using `# Ticket | [](^https://issues.acme.com/)`

2) Many projects ask people who submit bugs to check off whether they've searched for existing bugs. `- [x] I've looked in the bug tracker for existing bugs`

iJohnDoe · a year ago
Agreed. At least 5 examples of output shown being used against a standard markdown document.
pokstad · a year ago
Please don’t reimplement JQ. That problem is already solved. Instead, just provide a tool that can convert your target syntax into JSON, then it can be piped to JQ for querying.
kbd · a year ago
Cool thanks for sharing! I'll have to check this out. I've wanted something similar.

After trying a bunch of the usual ones, the only "notes system" I've stuck with is just a directory of markdown files that's automatically committed to git on any change using watchexec.

I've wanted to add a little smarts to it so I could use it to track tasks (eg. sort, prune completed, forward uncomplete tasks over to the next day's journal, collect tasks from "projects", etc.) so I started writing some Rust code using markdown-rs. Then, to round-trip markdown with changes, only the javascript version of the library currently supports serializing github flavored markdown. So then I actually dumped the markdown ast to json from rust and picked it up in js to serialize it for a proof of concept. That's about as far as I got so far. But while markdown-rs saves position information, it doesn't save source token information (like, * and - are both list items) so you can't reliably round-trip.

FWIW, the other thing I was hoping to do was treat markdown documents as trees (based on headings) use an xpath kind of language to pull out sections. Anyway, will check out your code, thanks for posting.

threecheese · a year ago
Interesting; one thing you may have learned researching existing tools and libraries: many of them serialize markdown to html before running structured extraction/manipulation - even stuff like converting to pdf.

The core assumption here is that Markdown was/is designed to be serializeable to html - this is why a markdown document/AST is mostly not a tree structure, for tree-ish elements such as sub-sections. Instead, it is flat, an array of elements in order of appearance in the document. Apparently this most closely matches the structure of html, at both the block and inline levels. Only Lists and Blockquotes (afair) support nesting.

Ex: h1 -> paragraph -> h2 -> paragraph is not nested, it is an array of four ordered elements.

Anyway, you might throw a task at Cursor or Copilot to see how an equivalent implementation using html fares against your test suite, you may be able to develop more quickly.