Function _isAlpha

packages/icu-messageformat-parser/parser.ts:1270–1275

* This check if codepoint is alphabet (lower & uppercase) * @param codepoint * @returns

(codepoint: number)

 * @returns
 */
function _isAlpha(codepoint: number): boolean {
  return (
    (codepoint >= 97 && codepoint <= 122) ||
    (codepoint >= 65 && codepoint <= 90)
  )
}

function _isAlphaOrSlash(codepoint: number): boolean {
  return _isAlpha(codepoint) || codepoint === 47 /* '/' */