What is unist-util-position?
The unist-util-position package is a utility for working with positional information in unist syntax trees. It provides functions to get and manipulate positions of nodes within these trees, which is useful for tasks such as error reporting, syntax highlighting, and more.
What are unist-util-position's main functionalities?
position.start
This feature retrieves the starting position of a node. The code sample demonstrates how to use the `position.start` function to get the starting line and column of a node.
const position = require('unist-util-position');
const node = { position: { start: { line: 1, column: 1 }, end: { line: 1, column: 5 } } };
console.log(position.start(node)); // { line: 1, column: 1 }
position.end
This feature retrieves the ending position of a node. The code sample shows how to use the `position.end` function to get the ending line and column of a node.
const position = require('unist-util-position');
const node = { position: { start: { line: 1, column: 1 }, end: { line: 1, column: 5 } } };
console.log(position.end(node)); // { line: 1, column: 5 }
position.point
This feature normalizes a point object. The code sample demonstrates how to use the `position.point` function to ensure a point object has the correct structure.
const position = require('unist-util-position');
const point = { line: 1, column: 1 };
console.log(position.point(point)); // { line: 1, column: 1 }
Other packages similar to unist-util-position
unist-util-visit
The unist-util-visit package is used to recursively walk through unist syntax trees. While it doesn't specifically handle positional information, it can be used in conjunction with unist-util-position to traverse nodes and then retrieve their positions.
unist-util-find
The unist-util-find package helps in finding nodes in unist syntax trees based on certain criteria. It can be used to locate nodes and then unist-util-position can be used to get their positional information.
unist-util-select
The unist-util-select package allows for selecting nodes in unist syntax trees using CSS-like selectors. Once nodes are selected, unist-util-position can be used to get their positions. This package is useful for more complex queries within the tree.
unist-util-position
unist utility to get positional info of nodes.
Contents
What is this?
This utility helps with accessing positional info on a potentially dirty tree.
When should I use this?
The positional info is typically consistent and proper in unist trees generated
by our ecosystem, but, user plugins could mess that up.
If you’re making a reusable plugin, and accessing the positional info often, you
might want to guard against that by using this utility.
You might also find the utility unist-util-generated
useful to check whether a node is considered to be generated (not in the
original input file).
You might also enjoy
unist-util-stringify-position
when you want
to display positional info to users.
Install
This package is ESM only.
In Node.js (version 16+), install with npm:
npm install unist-util-position
In Deno with esm.sh
:
import {pointEnd, pointStart, position} from 'https://esm.sh/unist-util-position@5'
In browsers with esm.sh
:
<script type="module">
import {pointEnd, pointStart, position} from 'https://esm.sh/unist-util-position@5?bundle'
</script>
Use
import {fromMarkdown} from 'mdast-util-from-markdown'
import {pointEnd, pointStart, position} from 'unist-util-position'
const tree = fromMarkdown('# foo\n\n* bar\n')
console.log(position(tree))
console.log(pointStart(tree))
console.log(pointEnd(tree))
Yields:
{start: {line: 1, column: 1, offset: 0}, end: {line: 4, column: 1, offset: 13}}
{line: 1, column: 1, offset: 0}
{line: 4, column: 1, offset: 13}
API
This package exports the identifiers pointEnd
,
pointStart
, and position
.
There is no default export.
position(node)
Get the positional info of node
.
Parameters
Returns
Position, if valid (Position
or undefined
).
pointEnd(node)
Get the ending point of node
.
Parameters
Returns
Point, if valid (Point
or undefined
).
pointStart(node)
Get the starting point of node
.
Parameters
Returns
Point, if valid (Point
or undefined
).
Types
This package is fully typed with TypeScript.
It exports no additional types.
Compatibility
Projects maintained by the unified collective are compatible with maintained
versions of Node.js.
When we cut a new major release, we drop support for unmaintained versions of
Node.
This means we try to keep the current release line, unist-util-position@^5
,
compatible with Node.js 16.
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, organization, or community you agree to
abide by its terms.
License
MIT © Titus Wormer