christianmurphy / unist-util-filter

unist utility to create a new tree with nodes that pass a filter

unist-util-filter

unist utility to create a new tree with all nodes that pass the given test.

Install

npm:

npm install unist-util-filter

Usage

var u = require('unist-builder')
var filter = require('unist-util-filter')

var tree = u('root', [
  u('leaf', '1'),
  u('node', [u('leaf', '2'), u('node', [u('leaf', '3')])]),
  u('leaf', '4')
])

var newTree = filter(tree, node => node.type !== 'leaf' || node.value % 2 === 0)

console.dir(newTree, {depth: null})

Yields:

{
  type: 'root',
  children: [
    { type: 'node', children: [ { type: 'leaf', value: '2' } ] },
    { type: 'leaf', value: '4' }
  ]
}

API

filter(tree[, options][, test])

Create a new tree consisting of copies of all nodes that pass test. The tree is walked in preorder (NLR), visiting the node itself, then its head, etc.

Parameters

• tree (Node?) — Tree to filter
• options.cascade (boolean, default: true) — Whether to drop parent nodes if they had children, but all their children were filtered out
• test (Test, optional) — is-compatible test (such as a type)

Returns

Node? — New filtered tree. null is returned if tree itself didn’t pass the test, or is cascaded away.

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