webpack/lib/util/LocConverter.js

Packs ECMAScript/CommonJs/AMD modules for the browser. Allows you to split your codebase into multiple bundles, which can be loaded on demand. Supports loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Alexander Akait @alexander-akait
*/

"use strict";

class LocConverter {
	/**
	 * Creates an instance of LocConverter.
	 * @param {string} input input
	 */
	constructor(input) {
		this._input = input;
		this.line = 1;
		this.column = 0;
		this.pos = 0;
	}

	/**
	 * Returns location converter.
	 * @param {number} pos position
	 * @returns {LocConverter} location converter
	 */
	get(pos) {
		if (this.pos !== pos) {
			if (this.pos < pos) {
				const str = this._input.slice(this.pos, pos);
				let i = str.lastIndexOf("\n");
				if (i === -1) {
					this.column += str.length;
				} else {
					this.column = str.length - i - 1;
					this.line++;
					while (i > 0 && (i = str.lastIndexOf("\n", i - 1)) !== -1) {
						this.line++;
					}
				}
			} else {
				let i = this._input.lastIndexOf("\n", this.pos);
				while (i >= pos) {
					this.line--;
					i = i > 0 ? this._input.lastIndexOf("\n", i - 1) : -1;
				}
				this.column = i === -1 ? pos : pos - i - 1;
			}
			this.pos = pos;
		}
		return this;
	}
}

module.exports = LocConverter;