The white space is always significant in mixed content.
But if this is allowed then I think the mixed content requirement is satisfied and in a natural and XML-similar way.
E.
Thanks, Eliot for your fast response.
How would XML mixed content be encoded in mark?
That is, if I have
<root>text1 <foo/> text2</root>
What does that look like in mark?
Otherwise, based on a first reading, it looks, syntactically, like it is structurally equivalent to XML except as regards attributes (in that structures within properties in mark could not be translated directly to XML attributes but could be translated to nested elements.
That is, there’s semantically no difference between
{root
prop: { foo: “bar”, baz: “blorg” }
}
And
{root
{prop foo: “bar”, baz: “blorg”}
}
In both cases the label “prop” is associated with the atomic properties foo and baz. (Which brings us back to the eternal “attributes or subelements?” question)
But I will observe that, while in XML the difference is very large syntactically, here in mark is quite small, which is interesting.
I definitely like having the explicit type label.
I will also observe that mark, with attributes restricted to simple values, could be defined as an alternative SGML syntax, as far as I can tell (without actually trying it, who actually remembers SGML syntax declaration syntax any more, or even has tools on hand to validate it?).
I’ve been doing work with MarkLogic lately, where you can use JSON instead of XML or explicitly-constructed maps to pass data structures around. I think I would find mark a syntactically-convenient alternative to XML and JSON for that purpose: I find it annoying that JSON does not have mark’s object type label but XML syntax is verbose when you’re just trying to create a data structure that’s not just a set of name-value pairs.
But I wouldn’t use mark for existing XML applications where XML is primary human-authored source, for a number of reasons.
Cheers,
E.
Dear all,
I am happy to announce the first public beta release of Mark - a simple notation that unifies JSON and XML.
You can find out more about it at https://mark.js.org/
Objective Markup Notation, abbreviated as Mark or {mark}, is a new unified notation for both object and markup data. The notation is a superset of what can be represented by JSON, HTML and XML, but overcomes many limitations these popular data formats, yet still having a very clean syntax and simple data model.
Mark Sample
Below is a sample Mark object, representing a simple registration form:
{form // object type-name 'form'
{!-- comment --} // Mark pragma, similar to HTML comment
{div class:"form-group" // nested Mark object
{label for:"email" // object with property 'for'
"Email address:" // text needs to be quoted
}
{input type:"email", id:"email"} // object without any contents
}
{div class:"form-group"
{label for:"pwd" "Password"}
{input type:"password", id:"pwd"}
}
{button class:['btn','btn-info'] // property with complex values
'Submit' // text quoted with single quote
}
}
Mark Data Model
Mark object has a very clean and simple data model. Each Mark object has 3 facets of data:
- Type name, which is mapped to
object.constructor.name under _javascript_. - Properties, which is a collection of key-value pairs, stored as normal _javascript_ named properties.
- Contents, which is a list of content objects, stored as indexed properties inside the same _javascript_ object.
Mark utilizes a novel feature in _javascript_ that a plain JS object is actually array-like. It can contain both named properties and indexed properties.
Mark vs. JSON
Mark is a superset of JSON. It extends JSON notation with a type-name, and a list of content objects. Comparing to JSON, Mark has the following advantages:
- It has a type-name, which is important in identifying what the data represents; whereas JSON is actually an anonymous object, missing the type name.
- It can have nested content, which is common in all markup formats, and thus allows Mark to convenient represent document-oriented data, which is awkward for JSON.
- It incorporates most of the enhancements of JSON5 to JSON (e.g. allowing comments, property name without quotes, etc.), and makes the format more friendly for human.
Some disadvantages of Mark, comparing to JSON would be:
- It is no longer a strict subset of _javascript_ in syntax, although a Mark object is still a simple POJO.
- It does not yet have wide support, like JSON, at the moment.
Mark vs. XML
Comparing to XML, Mark has the following advantages:
- Mark properties can have complex object as value; whereas XML attribute values always need to be quoted and cannot have complex object as value, which is not flexible in syntax and data model.
- Mark syntax is much cleaner than XML. It does not have all the legacy things like DTD, and it does not have whitespace ambiguity.
- The data model produced by Mark is fully typed, like JSON; whereas XML is only semi-typed without schema.
What do you think?
With an unified notation and data model, one set of tools (parser, selector, query, validator, transformer, ...) can be used to process data previously stored in JSON, HTML or XML.
Do you thing Mark is a better generic data format than JSON or XML? Do you think it is worth all the effort to migrate to this new notation? ...
Looking forward to hear your feedback!
Regards
Henry
