include/Evaluator/Evaluator.h

0001 //==========================================================================
0002 //  AIDA Detector description implementation
0003 //--------------------------------------------------------------------------
0004 // Copyright (C) Organisation europeenne pour la Recherche nucleaire (CERN)
0005 // All rights reserved.
0006 //
0007 // For the licensing terms see $DD4hepINSTALL/LICENSE.
0008 // For the list of contributors see $DD4hepINSTALL/doc/CREDITS.
0009 //
0010 //==========================================================================
0011
0012 #ifndef EVALUATOR_EVALUATOR_H
0013 #define EVALUATOR_EVALUATOR_H
0014
0015 /// C/C++ include files
0016 #include <ostream>
0017 #include <string>
0018
0019 /// Namespace for the AIDA detector description toolkit
0020 namespace dd4hep  {
0021
0022   /// Namespace containing XML tools.
0023   namespace tools {
0024
0025     /// Evaluator of arithmetic expressions with an extendable dictionary.
0026     /**
0027      * Taken from CLHEP 1.9.2.1
0028      *
0029      * Example:
0030      * @code
0031      *   #include "XmlTools/Evaluator.h"
0032      *   XmlTools::Evaluator eval;
0033      *   eval.setStdMath();
0034      *   double res = eval.evaluate("sin(30*degree)");
0035      *   if (eval.status() != XmlTools::Evaluator::OK) eval.print_error();
0036      * @endcode
0037      *
0038      * @author Evgeni Chernyaev <Evgueni.Tcherniaev@cern.ch>
0039      * @ingroup evaluator
0040      */
0041     class Evaluator {
0042     public:
0043
0044       /**
0045        * List of possible statuses.
0046        * Status of the last operation can be obtained with status().
0047        * In case if status() is an ERROR the corresponding error message
0048        * can be printed with print_error().
0049        *
0050        * @see status
0051        * @see error_position
0052        * @see print_error
0053        */
0054       enum {
0055         OK,                         /**< Everything OK */
0056         WARNING_EXISTING_VARIABLE,  /**< Redefinition of existing variable */
0057         WARNING_EXISTING_FUNCTION,  /**< Redefinition of existing function */
0058         WARNING_BLANK_STRING,       /**< Empty input string */
0059         ERROR_NOT_A_NAME,           /**< Not allowed symbol in the name of variable or function */
0060         ERROR_SYNTAX_ERROR,         /**< Syntax error */
0061         ERROR_UNPAIRED_PARENTHESIS, /**< Unpaired parenthesis */
0062         ERROR_UNEXPECTED_SYMBOL,    /**< Unexpected symbol */
0063         ERROR_UNKNOWN_VARIABLE,     /**< Non-existing variable */
0064         ERROR_UNKNOWN_FUNCTION,     /**< Non-existing function */
0065         ERROR_EMPTY_PARAMETER,      /**< Function call has empty parameter */
0066         ERROR_CALCULATION_ERROR     /**< Error during calculation */
0067       };
0068
0069       /**
0070        * Constructor.
0071        */
0072       Evaluator(double meter = 1.0, double kilogram = 1.0, double second = 1.0, double ampere = 1.0, double kelvin = 1.0
0073                 , double mole = 1.0, double candela = 1.0, double radians = 1.0);
0074
0075       /**
0076        * MoveConstructor.
0077        */
0078       Evaluator(Evaluator&&);
0079
0080       /**
0081        * Destructor.
0082        */
0083       ~Evaluator();
0084
0085       /**
0086        * Evaluates the arithmetic expression given as character string.
0087        * The expression may consist of numbers, variables and functions
0088        * separated by arithmetic (+, - , /, *, ^, **) and logical
0089        * operators (==, !=, >, >=, <, <=, &&, ||).
0090        *
0091        * @param  expression input expression.
0092        * @return pair(status,result) of the evaluation.
0093        */
0094       std::pair<int,double> evaluate(const std::string& expression)  const;
0095
0096       /**
0097        * Evaluates the arithmetic expression given as character string.
0098        * The expression may consist of numbers, variables and functions
0099        * separated by arithmetic (+, - , /, *, ^, **) and logical
0100        * operators (==, !=, >, >=, <, <=, &&, ||).
0101        *
0102        * @param  expression input expression.
0103        * @param  Possible stream identifier for error message
0104        * @return pair(status,result) of the evaluation.
0105        */
0106       std::pair<int,double> evaluate(const std::string& expression, std::ostream& os)  const;
0107
0108       /**
0109        * Adds to the dictionary a function without parameters.
0110        * If such a function already exist in the dictionary,
0111        * then status will be set to WARNING_EXISTING_FUNCTION.
0112        *
0113        * @param  name function name.
0114        * @param  fun pointer to the real function in the user code.
0115        * @return result of the evaluation.
0116        */
0117       int setFunction(const std::string& name, double (*fun)())  const;
0118
0119       /**
0120        * Adds to the dictionary a function with one parameter.
0121        * If such a function already exist in the dictionary,
0122        * then status will be set to WARNING_EXISTING_FUNCTION.
0123        *
0124        * @param  name function name.
0125        * @param  fun pointer to the real function in the user code.
0126        * @return result of the evaluation.
0127        */
0128       int setFunction(const std::string& name, double (*fun)(double))  const;
0129
0130       /**
0131        * Adds to the dictionary a function with two parameters.
0132        * If such a function already exist in the dictionary,
0133        * then status will be set to WARNING_EXISTING_FUNCTION.
0134        *
0135        * @param  name function name.
0136        * @param  fun pointer to the real function in the user code.
0137        * @return result of the evaluation.
0138        */
0139       int setFunction(const std::string& name, double (*fun)(double, double))  const;
0140
0141       /**
0142        * Adds to the dictionary a function with three parameters.
0143        * If such a function already exist in the dictionary,
0144        * then status will be set to WARNING_EXISTING_FUNCTION.
0145        *
0146        * @param  name function name.
0147        * @param  fun pointer to the real function in the user code.
0148        * @return result of the evaluation.
0149        */
0150       int setFunction(const std::string& name, double (*fun)(double, double, double))  const;
0151
0152       /**
0153        * Adds to the dictionary a function with four parameters.
0154        * If such a function already exist in the dictionary,
0155        * then status will be set to WARNING_EXISTING_FUNCTION.
0156        *
0157        * @param  name function name.
0158        * @param  fun pointer to the real function in the user code.
0159        * @return result of the evaluation.
0160        */
0161       int setFunction(const std::string& name, double (*fun)(double, double, double, double))  const;
0162
0163       /**
0164        * Adds to the dictionary a function with five parameters.
0165        * If such a function already exist in the dictionary,
0166        * then status will be set to WARNING_EXISTING_FUNCTION.
0167        *
0168        * @param  name function name.
0169        * @param  fun pointer to the real function in the user code.
0170        * @return result of the evaluation.
0171        */
0172       int setFunction(const std::string& name, double (*fun)(double, double, double, double, double))  const;
0173
0174       /**
0175        * Adds to the dictionary a string constant
0176        *
0177        * @param  name name of the variable.
0178        * @param  value value assigned to the variable.
0179        * @return result of the evaluation.
0180        */
0181       int setEnviron(const std::string& name, const std::string& value)  const;
0182
0183       /**
0184        * Lookup the dictionary for a string constant
0185        *
0186        * @param  name name of the variable.
0187        * @return pair(status,result) of the evaluation.
0188        */
0189       std::pair<int,std::string> getEnviron(const std::string& name)  const;
0190
0191       /**
0192        * Lookup the dictionary for a string constant
0193        *
0194        * @param  name name of the variable.
0195        * @param  stream identifier for error message
0196        * @return pair(status,result) of the evaluation.
0197        */
0198       std::pair<int,std::string> getEnviron(const std::string& name, std::ostream& os)  const;
0199
0200       /**
0201        * Adds to the dictionary a variable with given value.
0202        * If a variable with such a name already exist in the dictionary,
0203        * then status will be set to WARNING_EXISTING_VARIABLE.
0204        *
0205        * @param  name name of the variable.
0206        * @param  value value assigned to the variable.
0207        * @return result of the evaluation.
0208        */
0209       int setVariable(const std::string& name, double value)  const;
0210
0211       /**
0212        * Adds to the dictionary a variable with given value.
0213        * If a variable with such a name already exist in the dictionary,
0214        * then status will be set to WARNING_EXISTING_VARIABLE.
0215        *
0216        * @param  name name of the variable.
0217        * @param  value value assigned to the variable.
0218        * @return result of the evaluation.
0219        */
0220       int setVariable(const std::string& name, double value, std::ostream& os)  const;
0221
0222       /**
0223        * Adds to the dictionary a variable with an arithmetic expression
0224        * assigned to it.
0225        * If a variable with such a name already exist in the dictionary,
0226        * then status will be set to WARNING_EXISTING_VARIABLE.
0227        *
0228        * @param  name name of the variable.
0229        * @param  expression arithmetic expression.
0230        * @return result of the evaluation.
0231        */
0232       int setVariable(const std::string& name, const std::string& expression)  const;
0233
0234       /**
0235        * Adds to the dictionary a variable with an arithmetic expression
0236        * assigned to it.
0237        * If a variable with such a name already exist in the dictionary,
0238        * then status will be set to WARNING_EXISTING_VARIABLE.
0239        *
0240        * @param  name name of the variable.
0241        * @param  expression arithmetic expression.
0242        * @param  stream identifier for error message
0243        * @return result of the evaluation.
0244        */
0245       int setVariable(const std::string& name, const std::string& expression, std::ostream& os)  const;
0246
0247       /**
0248        * Finds the variable in the dictionary.
0249        *
0250        * @param  name name of the variable.
0251        * @return true if such a variable exists, false otherwise.
0252        */
0253       bool findVariable(const std::string& name)  const;
0254
0255       /**
0256        * Finds the function in the dictionary.
0257        *
0258        * @param  name name of the function to be unset.
0259        * @param  npar number of parameters of the function.
0260        * @return true if such a function exists, false otherwise.
0261        */
0262       bool findFunction(const std::string& name, int npar)   const;
0263
0264       class Object;
0265
0266     private:
0267       Object* object = 0;                                  // internal data
0268       Evaluator(const Evaluator &) = delete;               // copy constructor is not allowed
0269       Evaluator & operator=(const Evaluator &) = delete;   // assignment is not allowed
0270     };
0271
0272   }   // namespace tools
0273 }  // namespace dd4hep
0274
0275 #endif // EVALUATOR_EVALUATOR_H