unist-util-position

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.

README

unist-util-position

unist utility to get the position of nodes.

Installation

npm:

npm install unist-util-position

unist-util-position is also available as an AMD, CommonJS, and globals module, uncompressed and compressed.

Usage

var remark = require('remark');
var position = require('unist-util-position');

var ast = remark().parse([
    '# foo',
    '',
    '* bar',
    ''
].join('\n'));

position.start(ast) // {line: 1, column: 1}
position.end(ast) // {line: 4, column: 1}
position.generated(ast) // false

position.start() // {line: null, column: null}
position.end() // {line: null, column: null}
position.generated() // true

API

position.start([node])

position.end([node])

Get the bound position of node.

Parameters

• node (Node?) — Node to check.

Returns

Position — Filled with line (nullable uint32 >= 1), column (nullable uint32 >= 1), offset (nullable uint32 >= 0).

position.generated([node])

Get the heading style of a node.

Parameters

• node (Node) — Node to check;

Returns

boolean — Whether or not node has positional information (both starting and ending lines and columns). This is useful when checking if a node is inserted by plug-ins.

License

MIT © Titus Wormer