Function isKeyStart

http/unstable_structured_fields.ts:467–469

Check if character is valid at the start of a key (lcalpha or "*")

(c: string)

/** Check if character is valid at the start of a key (lcalpha or "*") */
function isKeyStart(c: string): boolean {
  return isLcalpha(c) || c === "*";
}

/** Check if character is valid within a key (lcalpha / DIGIT / "_" / "-" / "." / "*") */
function isKeyChar(c: string): boolean {