C++ mu::varmap_type类代码示例

/** \brief Return a variable that is used in an expression.

    Prior to calling this function call mupGetExprVarNum in order to get the
    number of variables in the expression. If the parameter a_iVar is greater
    than the number of variables both a_szName and a_pVar will be set to zero.
    As a side effect this function will trigger an internal calculation of the
    expression undefined variables will be set to zero during this calculation.
    During the calculation user defined callback functions present in the expression
    will be called, this is unavoidable.

    \param a_hParser [in] A valid parser handle.
    \param a_iVar [in] The index of the variable to return.
    \param a_szName [out] Pointer to the variable name.
    \param a_pVar [out] Pointer to the variable.
    \throw nothrow
*/
API_EXPORT(void) mupGetExprVar(muParserHandle_t a_hParser, unsigned a_iVar, const char **a_szName, double **a_pVar)
{
  // A static buffer is needed for the name since i cant return the
  // pointer from the map.
  static char  szName[1024];

  MU_TRY
    muParser_t* const p(AsParser(a_hParser));
    const mu::varmap_type VarMap = p->GetUsedVar();

    if (a_iVar>=VarMap.size())
    {
     *a_szName = 0;
     *a_pVar = 0;
      return;
    }
    mu::varmap_type::const_iterator item;

    item = VarMap.begin();
    for (unsigned i=0; i<a_iVar; ++i)
      item++;

     strncpy(szName, item->first.c_str(), sizeof(szName));
     szName[sizeof(szName)-1] = 0;

    *a_szName = &szName[0];
    *a_pVar = item->second;
     return;

  MU_CATCH

  *a_szName = 0;
  *a_pVar = 0;
}

/** \brief Get the number of variables used in the expression currently set in the parser.
    \param a_hParser [in] Must be a valid parser handle.
    \return The number of used variables.
    \sa mupGetExprVar
*/
API_EXPORT(int) mupGetExprVarNum(muParserHandle_t a_hParser)
{
  MU_TRY
    muParser_t* const p(AsParser(a_hParser));
    const mu::varmap_type VarMap = p->GetUsedVar();
    return (int)VarMap.size();
  MU_CATCH

  return 0; // never reached
}

/** \brief Return a variable that is used in an expression.
    \param a_hParser [in] A valid parser handle.
    \param a_iVar [in] The index of the variable to return.
    \param a_szName [out] Pointer to the variable name.
    \param a_pVar [out] Pointer to the variable.
    \throw nothrow

    Prior to calling this function call mupGetExprVarNum in order to get the
    number of variables in the expression. If the parameter a_iVar is greater
    than the number of variables both a_szName and a_pVar will be set to zero.
    As a side effect this function will trigger an internal calculation of the
    expression undefined variables will be set to zero during this calculation.
    During the calculation user defined callback functions present in the expression
    will be called, this is unavoidable.
    */
API_EXPORT(void) mupGetVar(muParserHandle_t a_hParser,
    unsigned a_iVar,
    const muChar_t **a_szName,
    muFloat_t **a_pVar)
{
    // A static buffer is needed for the name since i cant return the
    // pointer from the map.
    static muChar_t  szName[1024];

    MU_TRY
        muParser_t* const p(AsParser(a_hParser));
    const mu::varmap_type VarMap = p->GetVar();

    if (a_iVar >= VarMap.size())
    {
        *a_szName = 0;
        *a_pVar = 0;
        return;
    }
    mu::varmap_type::const_iterator item;

    item = VarMap.begin();
    for (unsigned i = 0; i < a_iVar; ++i)
        ++item;

#ifndef _UNICODE
    strncpy(szName, item->first.c_str(), sizeof(szName));
#else
    wcsncpy(szName, item->first.c_str(), sizeof(szName));
#endif

    szName[sizeof(szName)-1] = 0;

    *a_szName = &szName[0];
    *a_pVar = item->second;
    return;

    MU_CATCH

        *a_szName = 0;
    *a_pVar = 0;
}