class ERB::Compiler

def compile(s)

and encoding like ["code", Encoding].
Compiles an ERB template into Ruby code. Returns an array of the code 
def compile(s)
  enc = s.encoding
  raise ArgumentError, "#{enc} is not ASCII compatible" if enc.dummy?
  s = s.b # see String#b
  magic_comment = detect_magic_comment(s, enc)
  out = Buffer.new(self, *magic_comment)
  self.content = +''
  scanner = make_scanner(s)
  scanner.scan do |token|
    next if token.nil?
    next if token == ''
    if scanner.stag.nil?
      compile_stag(token, out, scanner)
    else
      compile_etag(token, out, scanner)
    end
  end
  add_put_cmd(out, content) if content.size > 0
  out.close
  return out.script, *magic_comment
end