// Phase 163: Test _parse_number from JsonParserBox (Pattern2 with break)
// Simulates: loop(digit_pos >= 0) { num_str += ch; p++; break if non-digit }

static box Main {
  main(args) {
    local num_str = "12345abc"
    local i = 0
    local digits = "0123456789"
    local result = ""

    // Simulate _parse_number: collect digits until non-digit
    loop(i < num_str.length()) {
      local ch = num_str.substring(i, i + 1)
      local digit_pos = digits.indexOf(ch)

      // Exit on non-digit
      if digit_pos < 0 {
        break
      }

      // Append digit
      result = result + ch
      i = i + 1
    }

    print("Input: " + num_str)
    print("Parsed: " + result)
    print("Stopped at index: " + ("" + i))
    return 0
  }
}