vfile-location

What is vfile-location?

The vfile-location npm package is a utility tool for working with virtual file objects, specifically designed to map positions in a virtual file to line and column-based locations. This is particularly useful when dealing with transformations or manipulations of text where tracking positions within the original and modified content is necessary.

What are vfile-location's main functionalities?

Location Mapping

This feature allows you to convert between line and column-based locations and absolute positions within a file's content. The `toOffset` method converts a line and column object to a zero-based offset, and the `toPoint` method converts an offset back to a line and column object.

const vfileLocation = require('vfile-location');
const text = 'Hello\nWorld';
const location = vfileLocation(text);

// Get position from line and column
const offset = location.toOffset({line: 2, column: 1}); // Returns 7

// Get line and column from position
const point = location.toPoint(offset); // Returns {line: 2, column: 1}

Other packages similar to vfile-location

line-column

The 'line-column' npm package provides similar functionality to vfile-location, allowing users to find the line and column position from a character index and vice versa. It differs in its API design and additional options for customization, such as setting the origin index.

columnify

While primarily focused on creating text-based columns for display, 'columnify' can also be used to manage text positions similarly to vfile-location. It is more specialized in creating aligned text output but includes position tracking as part of its layout capabilities.

README

vfile-location

Convert between positional (line and column-based) and offsets (range-based) locations in a virtual file.

Install

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

npm:

npm install vfile-location

Use

import {VFile} from 'vfile'
import {location} from 'vfile-location'

var place = location(new VFile('foo\nbar\nbaz'))

var offset = place.toOffset({line: 3, column: 3}) // => 10
place.toPoint(offset) // => {line: 3, column: 3, offset: 10}

API

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

place = location(doc)

Get transform functions for the given doc (string) or file.

Returns an object with toOffset and toPoint.

place.toOffset(point)

Get the offset (number) for a line and column-based point in the bound file. Returns -1 when given invalid or out of bounds input.

place.toPoint(offset)

Get the line and column-based point for offset in the bound file.

Contribute

See contributing.md in vfile/.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