122 lines
3.1 KiB
Plaintext
122 lines
3.1 KiB
Plaintext
/**
|
|
* @typedef {import('vfile').VFile} VFile
|
|
* @typedef {import('vfile').Value} Value
|
|
* @typedef {import('unist').Point} UnistPoint
|
|
*/
|
|
|
|
/**
|
|
*
|
|
* @typedef PointLike
|
|
* unist point, allowed as input.
|
|
* @property {number | null | undefined} [line]
|
|
* Line.
|
|
* @property {number | null | undefined} [column]
|
|
* Column.
|
|
* @property {number | null | undefined} [offset]
|
|
* Offset.
|
|
*
|
|
* @callback ToPoint
|
|
* Get the line/column based `Point` for `offset` in the bound indices.
|
|
*
|
|
* Returns `undefined` when given out of bounds input.
|
|
*
|
|
* Also implemented in Rust in [`wooorm/markdown-rs`][markdown-rs].
|
|
*
|
|
* [markdown-rs]: https://github.com/wooorm/markdown-rs/blob/main/src/util/location.rs
|
|
* @param {number | null | undefined} [offset]
|
|
* Something that should be an `offset.
|
|
* @returns {UnistPoint | undefined}
|
|
* Point, if `offset` is valid and in-bounds input.
|
|
*
|
|
* @callback ToOffset
|
|
* Get the `offset` from a line/column based `Point` in the bound indices.
|
|
* @param {PointLike | null | undefined} [point]
|
|
* Something that should be a `point.
|
|
* @returns {number | undefined}
|
|
* Offset (`number`) or `undefined` for invalid or out of bounds input.
|
|
*
|
|
* @typedef Location
|
|
* Accessors for index.
|
|
* @property {ToPoint} toPoint
|
|
* Get the line/column based `Point` for `offset` in the bound indices.
|
|
* @property {ToOffset} toOffset
|
|
* Get the `offset` from a line/column based `Point` in the bound indices.
|
|
*/
|
|
|
|
const search = /\r?\n|\r/g
|
|
|
|
/**
|
|
* Create an index of the given document to translate between line/column and
|
|
* offset based positional info.
|
|
*
|
|
* Also implemented in Rust in [`wooorm/markdown-rs`][markdown-rs].
|
|
*
|
|
* [markdown-rs]: https://github.com/wooorm/markdown-rs/blob/main/src/util/location.rs
|
|
*
|
|
* @param {VFile | Value} file
|
|
* File to index.
|
|
* @returns {Location}
|
|
* Accessors for index.
|
|
*/
|
|
export function location(file) {
|
|
const value = String(file)
|
|
/**
|
|
* List, where each index is a line number (0-based), and each value is the
|
|
* byte index *after* where the line ends.
|
|
*
|
|
* @type {Array<number>}
|
|
*/
|
|
const indices = []
|
|
|
|
search.lastIndex = 0
|
|
|
|
while (search.test(value)) {
|
|
indices.push(search.lastIndex)
|
|
}
|
|
|
|
indices.push(value.length + 1)
|
|
|
|
return {toPoint, toOffset}
|
|
|
|
/** @type {ToPoint} */
|
|
function toPoint(offset) {
|
|
let index = -1
|
|
|
|
if (
|
|
typeof offset === 'number' &&
|
|
offset > -1 &&
|
|
offset < indices[indices.length - 1]
|
|
) {
|
|
while (++index < indices.length) {
|
|
if (indices[index] > offset) {
|
|
return {
|
|
line: index + 1,
|
|
column: offset - (index > 0 ? indices[index - 1] : 0) + 1,
|
|
offset
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/** @type {ToOffset} */
|
|
function toOffset(point) {
|
|
const line = point && point.line
|
|
const column = point && point.column
|
|
|
|
if (
|
|
typeof line === 'number' &&
|
|
typeof column === 'number' &&
|
|
!Number.isNaN(line) &&
|
|
!Number.isNaN(column) &&
|
|
line - 1 in indices
|
|
) {
|
|
const offset = (indices[line - 2] || 0) + column - 1 || 0
|
|
|
|
if (offset > -1 && offset < indices[indices.length - 1]) {
|
|
return offset
|
|
}
|
|
}
|
|
}
|
|
}
|