writing VS markup-experiments

I had the same idea. Simple enough, but still. Brackets are simpler to formalize and implement and not harder to explain.

> They also put some thought into designing a query language for their rose-tree-like data model, which might be adaptable to Jevko — though they label only nodes, and Jevko labels both nodes (with suffixes) and arcs (with prefixes).

Yes, that might be interesting to look at, thanks for pointing it out. I have thought about this and came up with some ideas, but haven't decided on anything. I was thinking more along the lines of having the path DSL be simply implemented on top of Jevko, not as a completely separate grammar.

> Maybe that's the subtitle for Jevko? "A minimal Unicode syntax for ordered trees with labeled nodes and labeled arcs." If that's the intended semantics it would be pretty easy to whip up a diagram in Dot to illustrate it.

It's a nice description, but I think a little to detailed and technical to fit into a tagline. Maybe a little explanatory article with the diagram included. Would probably look something like this:

https://github.com/jevko/writing/blob/main/2022-01-10-jevko-...

Although I'd gladly see your take on it. ;)

Responding to some points I left off here https://news.ycombinator.com/item?id=33336789

I guess the main one is this:

> If your audience is people like me, I think it would probably be worthwhile for you to spend some time up front describing the intended semantics of a data model, as I've attempted above, rather than leaving people to infer it from the grammar. (Maybe OCaml is not a good way to explain it, though.) You might also want to specify that leading and trailing whitespace in prefixes is not significant, though it is in the suffix ("body"); this would enable people to format their name-value pairs readably without corrupting the data. As far as I can tell, this addendum wouldn't interfere with any of your existing uses for Jevko, though in some cases it would simplify their implementations.

You're right, things should be explained more clearly (TODO). Especially the exact role of Jevko and treatment of whitespace. I'll try to improve that.

Here is a sketch of an explanation.

Plain Jevko is meant to be a low-level syntactic layer.

It takes care of turning a unicode sequence into a tree.

On this level, all whitespace is preserved in the tree.

To represent key-value pairs and other data, you most likely want another layer above Jevko -- this would be a Jevko-based format, such as queryjevko (somewhat explained below) or, a very similar one, easyjevko, implemented and very lightly documented here: https://github.com/jevko/easyjevko.js

Or you could have a markup format, such as https://github.com/jevko/markup-experiments#asttoxml5

This format layer defines certain restrictions which may make a subset of Jevkos invalid in it.

It also specifies how to interpret the valid Jevkos. This includes the treatment of whitespace, e.g. that a leading or trailing whitespace in prefixes is insignificant, but conditionally significant in suffixes, etc.

Different formats will define different restrictions and interpretations.

For example:

# queryjevko

queryjevko is a format which uses (a variant of) Jevko as a syntax. Only a subset of Jevko is valid queryjevko.

> I think this is a more useful level of abstraction, and it's more or less the level used by, for example, queryjevko.js's jevkoToJs, although that erroneously uses () instead of [].

The `()` are used on purpose -- queryjevko is meant to be used in URL query strings and be readable. If square brackets were used, things like JS' encodeURIComponent would escape them, making the string unreadable. Using `()` solves that. "~" is used instead of "`" for the same reason. So technically we are dealing not with a spec-compliant Jevko, but a trivial variant of it. Maybe I should write a meta-spec which allows one to pick the three special characters before instantiating itself into a spec. Anyway the parser implementation is configurable in that regard, so I simply configure it to use "~()" instead of "`[]".

> (Also, contrary to your assertion above that this is an example of "leaving [Jevko's data model] as-is", it forgets the order of the name-value pairs as well as I guess all but one of any duplicate set of fields with the same name and also the possibility that there could be both fields and a body.)

I meant [whitespace] rather than [Jevko's data model].

Again, queryjevko is a format which uses Jevko as an underlying syntax. It specifies how syntax trees are converted to JS values, by restricting the range of valid Jevkos. It also specifies conversion in the opposite direction, likewise placing restrictions on JS values that can be safely converted to queryjevko.

The order of name-value pairs happens to get preserved (because of the way JS works), but that's not necessarily relevant. If I were to write a cross-language spec for queryjevko, I'd probably specify that this shouldn't be relied upon.

Duplicate fields and Jevkos with both fields and a non-whitespace body will produce an error when converting Jevko->JS.

I hope this clarifies things somewhat.

Lastly, I'll respond to this for completeness:

> (By the way, if you want to attribute your JSON example for copyright reasons, you need to attribute it to its author or authors, not to the Wikipedia, which is just the site they posted it on.)

According to this:

https://en.wikipedia.org/wiki/Wikipedia:Reusing_Wikipedia_co...

there are 3 options, one of them being what I did, which is to include a link.

I think that's all.

Have a good one!

Thank you. :)

> I wonder if I should use it for something...

I'd be honored!

A couple of ideas:

How about a simple configuration format? https://gist.github.com/djedr/681e0199859874b3324eaa84192c42... (I should make a library out of this)

Or you can put it in your query strings to make them more humane: https://github.com/jevko/queryjevko.js

Or make up a markup DSL: https://github.com/jevko/markup-experiments#asttohtmltable

Or serialize game objects in your indie game. Or make it the interface of your experimental app. Or use it to shave off a few unnecessary characters off your data: https://jevko.github.io/compactness.html

No parser in your favorite language? A basic one should be only a couple dozen lines!

There are no specialized features here but also not many parsing challenges or edge cases.

Clearly, there are ways to simplify these things, but not many people seem to be really interested in that.

[1] https://github.com/jevko/markup-experiments#asttoxml7