#ifndef _utl_UnitEvaluator_h
#define _utl_UnitEvaluator_h

/*!
  \file UnitEvaluator.h

  \brief Unit evaluating class

  \author R. Sipos
*/

#include <utl/UnitGrammar.h>

#include <string>
#include <map>


namespace utl {

  class UnitEvaluator {

  public:
    typedef UnitGrammar::SymbolTable SymbolTable;

    UnitEvaluator(const SymbolTable& symbols) :
      fSymbolTable(symbols),
      fGrammar(symbols, fValue, fError)
    {
      fValue = 1;
      fError = UnitGrammar::eOk;
    }

    double Evaluate(const std::string& expression) const;

    std::string GetError() const;

    UnitGrammar::EErrors GetStatus() const { return fError; }

    const SymbolTable& GetSymbolTable() const { return fSymbolTable; }

  private:
    const SymbolTable& fSymbolTable;
    UnitGrammar fGrammar;
    mutable std::string fExpression;
    double fValue;

    mutable UnitGrammar::EErrors fError;
    mutable unsigned int fErrPosition;

  };

}


#endif