Function getCharRange

packages/editor/src/utils/text.ts:51–59

(text: string, offset: number)

 * @returns [start, end]
 */
export const getCharRange = (text: string, offset: number) => {
  let i = 0
  for (; i <= offset; ) {
    const end = i + getCharOffsetForward(text, i)
    if (end > offset) return [i, end]
    i = end
  }
  return [i, i + Math.min(text.length, 1)]
}

const isSpace = (char: string) => /\s/.test(char)
// http://www.unicode.org/charts/