unist-util-parents
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    2.0.0 • Public • Published

    unist-util-parents

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    unist utility to add references to parents on nodes in a tree.

    Instead of modifying the original syntax tree, this module returns a wrapper that makes it easier to traverse that tree.

    Algorithms that work on regular unist trees are (mostly) guaranteed to work on wrapped trees, and each wrapped node maintains a reference to the node from which it originated.

    Install

    This package is ESM only: Node 12+ is needed to use it and it must be imported instead of required.

    npm:

    npm install unist-util-parents

    Use

    import {u} from 'unist-builder'
    import {parents} from 'unist-util-parents'
    
    var tree = u('root', [
      u('leaf', 'leaf 1'),
      u('node', [
        u('leaf', 'leaf 2'),
        u('void'),
        u('node', [
          u('leaf', 'leaf 3'),
          u('node', [u('leaf', 'leaf 4')]),
          u('void'),
          u('leaf', 'leaf 5')
        ])
      ])
    ])
    
    var wrapped = parents(tree)
    
    // Leaf 4
    var node = wrapped.children[1].children[2].children[1].children[0]
    
    var chain = []
    while (node) {
      chain.unshift(node.type)
      node = node.parent
    }
    
    console.log(chain)

    Yields:

    ['root', 'node', 'node', 'node', 'leaf']

    API

    This package exports the following identifiers: parents. There is no default export.

    parents(tree)

    Returns a wrapped tree with a proxy that imposes two additional properties on all of its nodes:

    • parent — parent link (or null for the root node)
    • node — link to the original node

    None of these properties are enumerable, and the original tree is not changed. This means you can JSON.stringify the wrapped tree and it’s the same.

    wrapped.children returns array of wrapped child nodes, so that any recursive algorithm will work on a wrapped tree just as well.

    Remember to access .node before you commit any changes to a node.

    Parameters
    Returns

    Node — A wrapped node: shallow copy of the given node with non-enumerable references to node and parent, and if tree had children, they are wrapped as well.

    Related

    Contribute

    See contributing.md in syntax-tree/.github for ways to get started. See support.md for ways to get help.

    This project has a Code of Conduct. By interacting with this repository, organisation, or community you agree to abide by its terms.

    License

    MIT © Eugene Sharygin

    Install

    npm i unist-util-parents

    DownloadsWeekly Downloads

    1,626

    Version

    2.0.0

    License

    MIT

    Unpacked Size

    9.27 kB

    Total Files

    5

    Last publish

    Collaborators

    • wooorm
    • kmck