Function tokenize

packages/effect/src/JsonPatch.ts:302–308

* Tokenize a JSON Pointer into unescaped reference tokens. * * - `""` (empty pointer) refers to the root and returns `[]` * - Non-empty pointers must start with `/`

(pointer: string)

 * - Non-empty pointers must start with `/`
 */
function tokenize(pointer: string): Array<string> {
  if (pointer === "") return []
  if (pointer.charCodeAt(0) !== 47 /* "/" */) {
    throw new Error(`Invalid JSON Pointer, it must start with "/": ${JSON.stringify(pointer)}`)
  }
  return pointer.split("/").slice(1).map(unescapeToken)
}

/** Convert a reference token to a non-negative array index (rejects `-` and negatives). */
function toIndex(token: string): number {