static L<IntRange> lambdaMapLike genericStreaks(IIntPred pred, int n) {
  new L<IntRange> out;
  int i = 0;
  while (i < n) {
    int j = i;
    while (j < n && pred.get(j)) ++j;
    if (j > i)
      out.add(intRange(i, j));
    i = j+1;
  }
  ret out;
}

static L<IntRange> lambdaMapLike genericStreaks(int n, IIntPred pred) {
  ret genericStreaks(pred, n);
}

Began life as a copy of #1019037