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unist utility to create a new tree with only nodes that pass a test.

• What is this?
• When should I use this?
• Install
• Use
• API
  • filter(tree[, options][, test])
  • Options
• Types
• Compatibility
• Related
• Contribute
• License

This is a small utility that helps you clean a tree.

You can use this utility to remove things from a tree.This utility is very similar tounist-util-remove, whichchanges the given tree.Modifying a tree like that utility does is much faster on larger documents.

You can also walk the tree withunist-util-visit to removenodes.To create trees, useunist-builder.

This package isESM only.In Node.js (version 16+), install withnpm:

npm install unist-util-filter

In Deno withesm.sh:

import{filter}from'https://esm.sh/unist-util-filter@5'

In browsers withesm.sh:

<scripttype="module">import{filter}from'https://esm.sh/unist-util-filter@5?bundle'</script>

import{u}from'unist-builder'import{filter}from'unist-util-filter'consttree=u('root',[u('leaf','1'),u('parent',[u('leaf','2'),u('parent',[u('leaf','3')])]),u('leaf','4')])constnewTree=filter(tree,node=>node.type!=='leaf'||node.value%2===0)console.dir(newTree,{depth:null})

Yields:

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

This package exports the identifierfilter.There is no default export.

Create a newtree of copies of all nodes that passtest.

The tree is walked inpreorder (NLR), visiting the node itself, then itshead, etc.

• tree (Node)— tree to filter
• options (Options, optional)— configuration
• test (Test, optional)—unist-util-is compatible test

New filtered tree (Node orundefined).

undefined is returned iftree itself didn’t pass the test, or is cascadedaway.

Configuration (TypeScript type).

• cascade (boolean, default:true)— whether to drop parent nodes if they had children, but all theirchildren were filtered out

This package is fully typed withTypeScript.It exports the additional typeOptions.

Projects maintained by the unified collective are compatible with maintainedversions of Node.js.

When we cut a new major release, we drop support for unmaintained versions ofNode.This means we try to keep the current release line,unist-util-filter@^5,compatible with Node.js 16.

• unist-util-visit— walk the tree
• unist-util-visit-parents— walk the tree with a stack of parents
• unist-util-map— create a new tree with all nodes mapped by a given function
• unist-util-flatmap— create a new tree by mapping (to an array) by a given function
• unist-util-remove— remove nodes from a tree that pass a test
• unist-util-select— select nodes with CSS-like selectors

Seecontributing.md insyntax-tree/.github forways to get started.Seesupport.md for ways to get help.

This project has acode of conduct.By interacting with this repository, organization, or community you agree toabide by its terms.

MIT © Eugene Sharygin