src/Calculator.h

   1 /*******************************************************************************
   2  * Reverse Polish Notation calculator.                                         *
   3  * Copyright (c) 2007-2009, Samuel Fredrickson <kinghajj@gmail.com>            *
   4  * All rights reserved.                                                        *
   5  *                                                                             *
   6  * Redistribution and use in source and binary forms, with or without          *
   7  * modification, are permitted provided that the following conditions are met: *
   8  *     * Redistributions of source code must retain the above copyright        *
   9  *       notice, this list of conditions and the following disclaimer.         *
  10  *     * Redistributions in binary form must reproduce the above copyright     *
  11  *       notice, this list of conditions and the following disclaimer in the   *
  12  *       documentation and/or other materials provided with the distribution.  *
  13  *                                                                             *
  14  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``AS IS'' AND ANY EXPRESS *
  15  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED           *
  16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE      *
  17  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY        *
  18  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES  *
  19  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR          *
  20  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER  *
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  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY   *
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH *
  24  * DAMAGE.                                                                     *
  25  ******************************************************************************/
  26
  27 /*******************************************************************************
  28  * Calculator.h - header for the Calculator class.                             *
  29  ******************************************************************************/
  30
  31 #ifndef RPN_CALCULATOR_H
  32 #define RPN_CALCULATOR_H
  33
  34 #include <string>
  35 #include <vector>
  36 #include "typedefs.h"
  37
  38 namespace RPN
  39 {
  40     //! The main class for the program.
  41     class Calculator
  42     {
  43         //! Holds the calculator's status, i.e. whether it's running or not.
  44         enum Status
  45         {
  46             Continue,
  47             Stop
  48         };
  49
  50         Commands  commands;
  51         HelpItems helpItems;
  52         History   history;
  53         Operators operators;
  54         Status    status;
  55         Variables variables;
  56
  57         //! The command to duplicate the top item of the stack.
  58         void dup                   (std::vector<std::string>&);
  59         //! The command to exit the calculator.
  60         void exit                  (std::vector<std::string>&);
  61         //! Pops the topmost item from the stack.
  62         void pop                   (std::vector<std::string>&);
  63         //! Removes the top stack as long as there will be at least one left.
  64         void popHistory            (std::vector<std::string>&);
  65         //! The command to print the help list.
  66         void printHelp             (std::vector<std::string>&);
  67         //! Copies the top stack and pushes it onto the history.
  68         void pushHistory           (std::vector<std::string>&);
  69         //! The generic method to print the history.
  70         void printHistoryGeneric   (void (*)(Value));
  71         //! The command to print the history.
  72         void printHistory          (std::vector<std::string>&);
  73         //! The command to print the history in detail.
  74         void printHistoryDetailed(std::vector<std::string>&);
  75         //! The command to print the stack.
  76         void printStack            (std::vector<std::string>&);
  77         //! The command to print the stack in detail.
  78         void printStackDetailed    (std::vector<std::string>&);
  79         //! The generic method to print the variables.
  80         void printVariablesGeneric (void (*)(Value));
  81         //! The command to print the variables.
  82         void printVariables        (std::vector<std::string>&);
  83         //! The command to print the variables in detail.
  84         void printVariablesDetailed(std::vector<std::string>&);
  85         void printVersion          (std::vector<std::string>&);
  86         //! Pops the top item, then pushes its square root.
  87         void sqrtTop               (std::vector<std::string>&);
  88         //! Swaps the top two items of the stack.
  89         void swap                  (std::vector<std::string>&);
  90         //! Unsets a previously set variable.
  91         void unset                 (std::vector<std::string>&);
  92
  93         //! Returns true if there is at least one stack.
  94         bool HasStack() const { return history.size() != 0; }
  95
  96         //! Returns a reference to the current stack.
  97         Stack& CurrentStack() { return history.front(); }
  98         const Stack& CurrentStack() const { return history.front(); }
  99
 100         //! Returns the current stack's size.
 101         size_t StackSize() const
 102         {
 103             return HasStack() ? CurrentStack().size() : 0;
 104         }
 105
 106         //! Returns the topmost item of the current stack.
 107         Value TopmostItem() const
 108         {
 109             return HasStack() && StackSize() > 0 ? CurrentStack().front() : 0;
 110         }
 111
 112     public:
 113
 114         //! The default and only constructor.
 115         Calculator()
 116             : commands  (defaultCommands()),
 117               helpItems (defaultHelpItems()),
 118               history   (defaultHistory()),
 119               operators (defaultOperators()),
 120               status    (Continue),
 121               variables (defaultVariables())
 122         {
 123         }
 124
 125         //! Evaluates a string.
 126         void Eval(std::string input);
 127
 128         //! Returns true if the calculator is running.
 129         bool IsRunning() const { return status == Continue; }
 130
 131         //! Returns a map of the default commands.
 132         Commands defaultCommands();
 133
 134         //! Displays the top item of the stack.
 135         void Display() const;
 136     };
 137 }
 138
 139 #endif