JStringStream.hh

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#ifndef __JLANG__JSTRINGSTREAM__
#define __JLANG__JSTRINGSTREAM__
 
#include <sstream>
#include <fstream>
 
#include "JLang/JStreamState.hh"
 
 
/**
 * \author mdejong
 */
 
namespace JLANG {}
namespace JPP { using namespace JLANG; }
 
namespace JLANG {
 
  /**
   * Wrapper class around STL stringstream class to facilitate optional loading of data from file.
   */
  class JStringStream :
    public std::stringstream,
    public JStreamState
  {
  public:
    /**
     * Constructor.
     *
     * This constructor loads all data from given input stream.
     *
     * \param  in       input stream
     */
    JStringStream(std::istream& in) :
      std::stringstream(),
      JStreamState(in, static_cast<std::istream&>(*this))
    {
      using namespace std;
 
      istream::sentry sentry(in);   // skips white spaces
 
      if (sentry) {
        (*this) << in.rdbuf();
      }
    }
 
    
    /**
     * Load data from file with name corresponding to current contents.
     *
     * Note that if the file exists but is empty,
     * the state of the stream is set to fail by C++ standard.
     */
    void load()
    {
      using namespace std;
      
      ifstream in(this->str().c_str());
 
      if (in) {
 
        this->str("");                     // reset
 
        (*this) << in.rdbuf();             // copy
 
        in.close();
      }
    }
  };
}
 
#endif