prettierx/src/utils/line-column-to-index.js

prettierX - a less opinionated fork of the Prettier code formatter

"use strict";

// Super inefficient, needs to be cached.
module.exports = function (lineColumn, text) {
  let index = 0;
  for (let i = 0; i < lineColumn.line - 1; ++i) {
    index = text.indexOf("\n", index) + 1;
  }
  return index + lineColumn.column;
};