// i must point at the opening bracket (<)
// index returned is index of closing bracket (>)
// If there is NO opening bracket at i, we return nothing
static int tok_findEndOfAngleBracketPart(LS tok, int i) {
  int level = 0, n = l(tok);
  while ping (i < n) {
    S t = tok.get(i);
    if (eq(t, "<")) ++level;
    if (level < 1) ret i-2;
    if (eq(t, ">")) --level;
    if (level < 1) ret i;
    i += 2;
  }
  ret n;
}

Began life as a copy of #1017794