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4680 | right-hear | 1 | /** \file lispio.h |
2 | * definitions of pure input output classes. |
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3 | */ |
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4 | |||
5 | |||
6 | #ifndef __lispio_h__ |
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7 | #define __lispio_h__ |
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8 | |||
9 | #include "yacasbase.h" |
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10 | |||
11 | // Hope this forward declaration doesn't screw us over... |
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12 | class InputDirectories; |
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13 | class InputStatus : public YacasBase |
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14 | { |
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15 | public: |
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16 | InputStatus() : iFileName("none") , iLineNumber(-1) {}; |
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17 | ~InputStatus(); |
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18 | void SetTo(LispChar * aFileName); |
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19 | void RestoreFrom(InputStatus& aPreviousStatus); |
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20 | inline LispInt LineNumber(); |
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21 | inline LispChar * FileName(); |
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22 | inline void NextLine(); |
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23 | |||
24 | inline InputStatus(const InputStatus& aOther) : iFileName(aOther.iFileName) , iLineNumber(aOther.iLineNumber) |
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25 | { |
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26 | } |
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27 | |||
28 | inline InputStatus& operator=(const InputStatus& aOther) |
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29 | { |
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30 | iFileName = aOther.iFileName; |
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31 | iLineNumber = aOther.iLineNumber; |
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32 | return *this; |
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33 | } |
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34 | |||
35 | private: |
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36 | LispChar * iFileName; |
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37 | LispInt iLineNumber; |
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38 | }; |
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39 | |||
40 | inline LispInt InputStatus::LineNumber() |
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41 | { |
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42 | return iLineNumber; |
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43 | } |
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44 | inline LispChar * InputStatus::FileName() |
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45 | { |
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46 | return iFileName; |
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47 | } |
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48 | inline void InputStatus::NextLine() |
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49 | { |
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50 | iLineNumber++; |
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51 | } |
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52 | |||
53 | /** \class LispInput : pure abstract class declaring the interface |
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54 | * that needs to be implemented by a file (something that expressions |
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55 | * can be read from). |
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56 | */ |
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57 | class LispInput : public YacasBase |
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58 | { |
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59 | public: |
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60 | /** Constructor with InputStatus. InputStatus retains the information |
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61 | * needed when an error occurred, and the file has already been |
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62 | * closed. |
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63 | */ |
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64 | LispInput(InputStatus& aStatus) : iStatus(aStatus) {}; |
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65 | virtual ~LispInput(); |
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66 | |||
67 | /// Return the next character in the file |
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68 | virtual LispChar Next() = 0; |
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69 | |||
70 | /** Peek at the next character in the file, without advancing the file |
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71 | * pointer. |
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72 | */ |
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73 | virtual LispChar Peek() = 0; |
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74 | |||
75 | virtual InputStatus& Status() const {return iStatus;}; |
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76 | |||
77 | /// Check if the file position is past the end of the file. |
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78 | virtual LispBoolean EndOfStream() = 0; |
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79 | /** StartPtr returns the start of a buffer, if there is one. |
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80 | * Implementations of this class can keep the file in memory |
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81 | * as a whole, and return the start pointer and current position. |
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82 | * Especially the parsing code requires this, because it can then |
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83 | * efficiently look up a symbol in the hash table without having to |
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84 | * first create a buffer to hold the symbol in. If StartPtr is supported, |
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85 | * the whole file should be in memory for the whole period the file |
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86 | * is being read. |
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87 | */ |
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88 | virtual LispChar * StartPtr() = 0; |
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89 | virtual LispInt Position() = 0; |
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90 | virtual void SetPosition(LispInt aPosition) = 0; |
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91 | protected: |
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92 | InputStatus& iStatus; |
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93 | }; |
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94 | |||
95 | /** \class LispOutput : interface an output object should adhere to. |
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96 | */ |
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97 | class LispOutput : public YacasBase |
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98 | { |
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99 | public: |
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100 | virtual ~LispOutput(); |
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101 | /// Write out one character. |
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102 | virtual void PutChar(LispChar aChar) = 0; |
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103 | |||
104 | public: |
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105 | void Write(const LispChar * aString); |
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106 | }; |
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107 | |||
108 | #endif |
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109 |