Add sections on possible values · syntax-tree/unist@691de9c (original) (raw)
`@@ -20,13 +20,26 @@ See [nlcst][nlcst] for more information on retext nodes,
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`[mdast][mdast] for information on remark nodes, and
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`` [hast#nodes][hast-nodes] for information on hast nodes.
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Subsets of Unist can define new properties on new nodes, and plug-ins
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and utilities can define new data properties on nodes. But,
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the values on those properties must be JSON values: string,
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number, object, array, true, false, or null. This means
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that the syntax tree should be able to be converted to and from JSON
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and produce the same tree. For example, in JavaScript, a tree should
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be able to be passed through JSON.parse(JSON.stringify(tree)) and
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result in the same values.
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`` ### Node
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`Node represents any unit in the Unist hierarchy. It is an abstract
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`` class. Interfaces inheriting from Node must have a type property,
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`` and may have data or location properties. types are defined by
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`their namespace.
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Subsets of Unist are allowed to define properties on interfaces which
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subclass Unist’s abstract interfaces. For example, [mdast][] defines
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a link node (subclassing Parent) with a url property.
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```` ```idl
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`interface Node {
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` type: string;
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`@@ -37,9 +50,10 @@ interface Node {
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`` #### `Data`
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Data represents data associated with any node. Data is a scope for plug-ins
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to store any information. Its only limitation being that each property should
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by `stringify`able: not throw when passed to `JSON.stringify()`.
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Data represents data associated with any node. `Data` is a scope for
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plug-ins to store any information. For example, [`remark-html`][remark-html]
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uses `htmlAttributes` to let other plug-ins specify attributes added
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to the compiled HTML element.
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```` ```idl
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`interface Data { }
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`@@ -175,3 +189,9 @@ A list of VFile-related utilities can be found at [vfile][vfile].
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`[hast-nodes]: https://github.com/wooorm/hast#nodes
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`[vfile]: https://github.com/wooorm/vfile
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