// Phase 188: String append with character variable
// Pattern: s = s + ch (StringAppendChar)
// Pattern 2: Loop with conditional break

static box SAppendChar {
  method main() {
    local s = ""
    local i = 0
    loop(i < 10) {
      if i == 3 {
        break
      }
      local ch = "x"
      s = s + ch
      i = i + 1
    }
    print(s)  // Expected: "xxx"
  }
}