Function isBase64Char

http/unstable_structured_fields.ts:503–506

Check if character is a valid base64 character

(c: string)

/** Check if character is a valid base64 character */
function isBase64Char(c: string): boolean {
  const code = c.charCodeAt(0);
  return code < 128 && BASE64_LOOKUP[code]!;
}

/** Check if character is a lowercase hex digit (0-9, a-f) */
function isLcHexDigit(c: string): boolean {