Show HN: Mermaid ASCII Diagrams

This would be great to build into project readme workflows.

Some nits:

The "Example" buttons don't jump out at me; I found them but it took a while. Also consider labeling them with their point, e.g. "Example 3: Color"

If you change the input text to something well-formed, the graph seems to update immediately. But if you change it to something ill-formed, the graph doesn't update immediately — and then if you click "Generate" manually, it blanks the input box. Either this is a bug, or the "Generate" button doesn't do what I think it does (i.e. generate output). Again, adding a noun to the verb might help. Or just adding some usage information somewhere on the page.

For those like me who've never heard of "Mermaid," apparently it's like GraphViz's dot language but different. https://github.com/mermaid-js/mermaid I tried the flowchart example from Mermaid's own README, but it didn't come out right: looks like the shape characters [] and {} aren't handled.

Thanks for the feedback! I agree that the web UI can be improved (quite) a bit, most of my efforts went into the actual generation of the diagrams. I'll have a look at prettifying it.

I'm disappointed. I was actually expecting lovely ascii art pictures of mermaids.

You can already use Mermaid in GitHub markdown:

https://docs.github.com/en/get-started/writing-on-github/wor...

I supposed it's good for basic usage. I just tried a more complex graph and it didn't render well.

Same. This is more than a nit. It's pretty much a need.

Here you go: https://www.asciiart.eu/mythology/mermaids

GitLab as well

https://handbook.gitlab.com/handbook/tools-and-tips/#using-m...

Hey, where are the mermaids?!?

But now seriously.. the diagrams are working really well for simple examples, thank you so much for sharing this tool. I have bookmarked your page, my documentation is based on text files and often have to build these kind of diagrams too.

The example buttons took me a while to be found, but are good for syntax explanation. Thank you for making this available.

Azure DevOps wiki also supports Mermaid https://learn.microsoft.com/en-us/azure/devops/project/wiki/...

I don't like that it renders controls on top of the diagram.

Nice work, I love ascii diagrams. Especially useful when you want a visual explanation that can be embedded directly in source code.

Small nit on layout: 90 degree joints should use "+" in the connecting lines, as they do in the boxes.

Thanks for the kind words!

This obviously needs a direct pipe into Svgbob!

https://ivanceras.github.io/svgbob-editor/

love it, will definitely be using it for sketching documentation in comments for SQL sprocs, etc.

One request: support for self-reference, i.e. "A --> A", "A --> A & B"

Thanks, that's a good suggestion. I'm also noticing that's not working as intended.

Same, I had no idea there were examples until I read this.

Counter-nit: I found the examples within a few seconds.

Fixed in 0.5.0. Give it a try!

In the same vein: https://plantuml.com/ascii-art

Also: https://dot-to-ascii.ggerganov.com/

In the age of AI someone automated Mentifex[1]!

[1] https://nothingisreal.com/mentifex_faq.html

Needs to have a '+' and the elbows and T intersections.

Hah we rely on Mermaid a _heap_ at work for building internal dependency graphs from `yarn info` JSON data and a super lazy depth-first graph haha. Super useful, nice to see another renderer!

ts-directed-graph outputs Mermaid :)

This tool seems way more useful for hand-made ones, definitely bookmarking

Counter-counter-nit: I did not.

Out of interest have you managed to get Mermaid graphs rendering outside of a browser?

I was trying to do this a while back so I could do server side rendering of graphs, but it seemed to depend strongly on the presence of a DOM. Couldn’t quite get it working with JS-DOM either.

I use this for generating AWS deployment diagrams, which is kinda similar - https://github.com/mingrammer/diagrams