static box RuleUsingQuotedBox {
  apply(text, path, out) {
    local lines = me._split_lines(text)
    local i = 0
    while i < lines.size() {
      local ln = me._ltrim(lines.get(i))
      if ln.indexOf("using ") == 0 {
        if ln.indexOf('using "') != 0 { out.push("[HC003] using must be quoted: " + path + ":" + me._itoa(i+1)) }
      }
      i = i + 1
    }
  }
  _ltrim(s) { return me._ltrim_chars(s, " \t") }
  _itoa(n) { local v=0+n; if v==0 { return "0" } local out=""; local digits="0123456789"; local tmp=""; while v>0 { local d=v%10; tmp=digits.substring(d,d+1)+tmp; v=v/10 } out=tmp; return out }
  _split_lines(s) {
    local arr = new ArrayBox(); if s == null { return arr }
    local n = s.length(); local last = 0; local i = 0
    while i < n { local ch = s.substring(i,i+1); if ch == "\n" { arr.push(s.substring(last,i)); last = i+1 } i = i + 1 }
    arr.push(s.substring(last)); return arr
  }
  _ltrim_chars(s, cs) {
    local n = s.length(); local head = 0
    local i = 0
    while i < n {
      local ch = s.substring(i,i+1)
      if ch != " " && ch != "\t" { head = i; break }
      if i == n-1 { head = n }
      i = i + 1
    }
    return s.substring(head)
  }
}

static box RuleUsingQuotedMain { method main(args) { return 0 } }