class Compiler {
public:
  Compiler();
  virtual void Compile(istream&, BytecodeStream&);
};
void Compiler::Compile (istream& input, BytecodeStreamk output) {
  Scanner scanner(input);
  ProgramNodeBuilder builder;
  Parser parser;
 
  parser.Parse(scanner, builder);
 
  RISCCodeGenerator generator(output);
  ProgramNode* parseTree = builder.GetRootNode();
  parseTree->Traverse(generator);
}