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1 // Copyright (c) 2000-2009 Nokia Corporation and/or its subsidiary(-ies). |
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2 // All rights reserved. |
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3 // This component and the accompanying materials are made available |
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4 // under the terms of "Eclipse Public License v1.0" |
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5 // which accompanies this distribution, and is available |
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6 // at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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7 // |
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8 // Initial Contributors: |
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9 // Nokia Corporation - initial contribution. |
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10 // |
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11 // Contributors: |
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12 // |
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13 // Description: |
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14 // |
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15 |
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16 #include <cbnfparser.h> |
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17 |
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18 #include <cnodeleteattribute.h> |
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19 #include <attrlut.h> |
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20 #include <estatus.h> |
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21 #include <e32base.h> |
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22 |
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23 #include "BNFPanicCodes.h" |
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24 |
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25 |
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26 /** Allocates and constructs a new BNF parser. |
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27 |
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28 @return New parser |
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29 @param aLUT Attribute lookup table in which to store attributes for |
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30 the rule tree |
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31 */ |
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32 EXPORT_C CBNFParser* CBNFParser::NewL(CAttributeLookupTable& aLUT) |
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33 { |
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34 CBNFParser* model = new (ELeave) CBNFParser(aLUT); |
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35 return (model); |
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36 } |
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37 |
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38 /** Constructor. |
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39 |
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40 @param aLUT Attribute lookup table |
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41 */ |
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42 EXPORT_C CBNFParser::CBNFParser(CAttributeLookupTable& aLUT) |
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43 : iLUT(aLUT) |
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44 { |
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45 // store pointers to these to avoid continual unnecessary calls to the CBNFNode DLL |
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46 iReferenceString=CBNFNode::KReference(); |
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47 iRangeStart=CBNFNode::KRangeStart(); |
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48 iRangeEnd=CBNFNode::KRangeEnd(); |
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49 iMoreMinimum=CBNFNode::KNMoreMinimum(); |
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50 iMoreCount=CBNFNode::KNMoreCount(); |
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51 iMoreMaximum=CBNFNode::KNMoreMaximum(); |
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52 iPreRuleCallback=CBNFNode::KPreRuleCallback(); |
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53 iPostRuleCallback=CBNFNode::KPostRuleCallback(); |
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54 } |
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55 |
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56 /** Destructor. |
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57 */ |
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58 EXPORT_C CBNFParser::~CBNFParser() |
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59 { |
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60 delete iTree; |
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61 } |
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62 |
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63 /** Reset the parser to a state where it can accept and parse new input. |
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64 |
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65 If no BNF tree yet exists the virtual method TreeL() is called to obtain the BNF tree for this parser. |
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66 Any existing state of parsing and input data is destroyed. */ |
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67 EXPORT_C void CBNFParser::ResetL() |
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68 { |
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69 if (iTree == NULL) |
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70 iTree = TreeL(); |
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71 |
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72 iRuleStack.Clear(); |
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73 iRuleStack.PushL(iTree); |
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74 |
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75 iSubRuleMatched = EFalse; |
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76 iSubRule = NULL; |
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77 iStringComplete = EFalse; |
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78 iString.Reset(); |
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79 } |
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80 |
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81 /** Gets the attribute look-up table used by this parser. |
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82 |
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83 @return Attribute look-up table |
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84 */ |
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85 EXPORT_C CAttributeLookupTable& CBNFParser::AttributeLUT() const |
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86 { |
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87 return iLUT; |
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88 } |
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89 |
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90 /** Processes a reference rule node. |
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91 |
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92 It is called by PerformRuleL(). |
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93 |
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94 @return ETrue if the function completed processing this node, otherwise EFalse |
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95 @param aRule The rule node being processed |
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96 @param aMatched On return, flag indicating if input stream matched the rule |
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97 */ |
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98 EXPORT_C TBool CBNFParser::ReferenceL(CBNFNode& aRule, CFragmentedString::TStringMatch& /*aMatched*/) |
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99 // Handle a reference node. |
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100 // The pointer to the refered rule is stored as an attribute to a node which |
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101 // is stored as an attribute to the reference node. Nice and simple, isn't it? :-) |
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102 { |
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103 // new to this Reference, or returning from a sub match? |
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104 if (iSubRule) |
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105 // No operation is required when returning from the refered rule - continue up. |
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106 return ETrue; |
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107 else |
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108 { |
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109 CNoDeleteAttributeT<CBNFNode*>* attributeNode = REINTERPRET_CAST(CNoDeleteAttributeT<CBNFNode*>*, aRule.Attribute(iReferenceString)); |
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110 // iRuleStack.Pop(); //Optimisation not possible as other bnf parts use this 'rule' node to find the next sibling (i.e. And, Or etc) |
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111 iRuleStack.PushL(attributeNode->Attribute()); |
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112 } |
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113 return EFalse; |
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114 } |
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115 |
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116 /** Processes an EExact rule node. |
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117 |
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118 It is called by PerformRuleL(). |
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119 |
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120 @return ETrue if the function completed processing this node, otherwise EFalse |
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121 @param aRule The rule node being processed |
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122 @param aMatched On return, flag indicating if input stream matched the rule |
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123 */ |
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124 EXPORT_C TBool CBNFParser::ExactL(CBNFNode& aRule, CFragmentedString::TStringMatch& aMatched) |
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125 // Handle an EExact rule |
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126 // Attempts to match a string with the stream. |
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127 { |
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128 if ((aMatched=iString.Match(REINTERPRET_CAST(HBufC*, aRule.Data())->Des()))==CFragmentedString::EMatch) |
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129 iString.ConsumeMatched(); |
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130 return ETrue; |
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131 } |
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132 |
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133 /** Processes an ERange rule node. |
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134 |
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135 It is called by PerformRuleL(). |
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136 |
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137 @return ETrue if the function completed processing this node, otherwise EFalse |
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138 @param aRule The rule node being processed |
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139 @param aMatched On return, flag indicating if input stream matched the rule |
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140 */ |
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141 EXPORT_C TBool CBNFParser::RangeL(CBNFNode& aRule, CFragmentedString::TStringMatch& aMatched) |
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142 // Handle ERange rule |
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143 // Checks if the next character in the stream fits into the chracter range defined by the rule |
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144 { |
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145 CNoDeleteAttributeT<TInt>* rangeStartAttribute = REINTERPRET_CAST(CNoDeleteAttributeT<TInt>*, aRule.Attribute(iRangeStart)); |
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146 TInt rangeStart; |
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147 if (rangeStartAttribute) |
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148 rangeStart = rangeStartAttribute->Attribute(); |
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149 else |
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150 rangeStart = 0; |
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151 |
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152 CNoDeleteAttributeT<TInt>* rangeEndAttribute = REINTERPRET_CAST(CNoDeleteAttributeT<TInt>*, aRule.Attribute(iRangeEnd)); |
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153 TInt rangeEnd; |
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154 if (rangeEndAttribute) |
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155 rangeEnd = rangeEndAttribute->Attribute(); |
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156 else |
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157 rangeEnd = 0; |
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158 |
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159 if ((aMatched = iString.MatchRange(rangeStart, rangeEnd)) == CFragmentedString::EMatch) |
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160 iString.ConsumeMatched(); |
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161 return ETrue; |
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162 } |
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163 |
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164 |
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165 /** Processes an ESelect rule node. |
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166 |
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167 It is called by PerformRuleL(). |
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168 |
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169 @return ETrue if the function completed processing this node, otherwise EFalse |
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170 @param aRule The rule node being processed |
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171 @param aMatched On return, flag indicating if input stream matched the rule |
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172 */ |
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173 EXPORT_C TBool CBNFParser::SelectL(CBNFNode& aRule, CFragmentedString::TStringMatch& aMatched) |
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174 // Handle Select rule |
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175 // Check if the next character in the stream matches to any of the chracters included |
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176 // into the set defined by the select rule. |
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177 // The selection can also be performed as inverted selection (by using "^" as the first char) |
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178 // in which case all the other characters but the ones defined in the set match correctly to the stream. |
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179 { |
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180 if ((*aRule.Data())[0] == '^') |
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181 aMatched = iString.MatchNotSelect((*REINTERPRET_CAST(HBufC*, aRule.Data())).Mid(1)); |
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182 else |
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183 aMatched = iString.MatchSelect(*REINTERPRET_CAST(HBufC*, aRule.Data())); |
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184 |
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185 //! if (aMatched == CFragmentedString::EMatch) |
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186 iString.ConsumeMatched(); |
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187 return ETrue; |
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188 } |
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189 |
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190 /** Processes an EWithout rule node. |
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191 |
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192 It is called by PerformRuleL(). |
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193 |
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194 @return ETrue if the function completed processing this node, otherwise EFalse |
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195 @param aRule The rule node being processed |
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196 @param aMatched On return, flag indicating if input stream matched the rule |
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197 */ |
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198 EXPORT_C TBool CBNFParser::WithoutL(CBNFNode& aRule, CFragmentedString::TStringMatch& aMatched) |
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199 // Handle EWithout rule |
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200 // An example Without rule: [A-Z] - B |
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201 // Here we are trying to match all characters from A-Z except character B. |
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202 // The rule is performed here by first executing the latter part of the rule (in the example |
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203 // by trying to match B). If the latter rule matches, then the stream contains the chracter |
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204 // string we didn't want it to include and hence the Without rule is false. However, if the |
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205 // latter rule doesn't match we proceed to matching the first part of the rule and if it |
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206 // does match the whole Without rule is true. |
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207 // The Without rule node has two children of which the first one (child on index 0) |
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208 // is the rule we are trying to match and the second child is the "except" part of the rule. |
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209 { |
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210 TBool performedMatch = EFalse; |
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211 // new to this Without, or returning from a sub match? |
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212 CBNFNode* newRule = NULL; |
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213 if (iSubRule) |
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214 { |
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215 if (iSubRule == aRule.Child(1)) |
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216 { |
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217 iString.ResetToMark(); |
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218 iString.DeleteMark(); |
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219 if (!iSubRuleMatched) |
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220 newRule = REINTERPRET_CAST(CBNFNode*, aRule.Child(0)); |
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221 else |
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222 aMatched = CFragmentedString::ENoMatch; |
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223 } |
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224 } |
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225 else |
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226 { |
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227 iString.Mark(); // Mark can leave |
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228 StartConditional((enum TParserNodeTypes)aRule.Type()); |
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229 newRule = REINTERPRET_CAST(CBNFNode*, aRule.Child(1)); |
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230 } |
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231 if (newRule) |
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232 { |
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233 iRuleStack.PushL(newRule); |
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234 iSubRule = NULL; // going down |
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235 } |
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236 else |
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237 { |
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238 EndConditional((enum TParserNodeTypes)aRule.Type(), iSubRuleMatched); |
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239 performedMatch = ETrue; |
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240 } |
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241 return performedMatch; |
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242 } |
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243 |
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244 /** Processes an EAnd rule node. |
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245 |
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246 It is called by PerformRuleL(). |
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247 |
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248 @return ETrue if the function completed processing this node, otherwise EFalse |
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249 @param aRule The rule node being processed |
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250 @param aMatched On return, flag indicating if input stream matched the rule |
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251 */ |
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252 EXPORT_C TBool CBNFParser::AndL(CBNFNode& aRule, CFragmentedString::TStringMatch& /*aMatched*/) |
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253 // Handle And rule |
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254 // An EAnd rule is true if all of its children are true. Processing the child nodes of |
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255 // the And rule continues until all the children has been processed of one of them doesn't |
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256 // match. Notice, that the order of the child rules has signifigance, since we are |
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257 // matching a chracter stream and the first child is matched first, followed by the second etc. |
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258 { |
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259 TBool performedMatch = EFalse; |
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260 // new to this And, or returning from a sub match? |
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261 CBNFNode* newRule = NULL; |
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262 if (iSubRule) |
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263 { |
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264 if (iSubRuleMatched) |
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265 { |
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266 newRule = REINTERPRET_CAST(CBNFNode*, iSubRule->NextSibling()); |
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267 if (!newRule) |
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268 performedMatch = ETrue; |
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269 } |
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270 else |
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271 performedMatch = ETrue; |
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272 } |
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273 else |
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274 { |
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275 newRule = REINTERPRET_CAST(CBNFNode*, aRule.Child(0)); |
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276 StartConditional((enum TParserNodeTypes)aRule.Type()); |
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277 } |
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278 if (newRule) |
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279 { |
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280 iRuleStack.PushL(newRule); |
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281 iSubRule = NULL; // going down |
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282 } |
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283 else |
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284 { |
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285 EndConditional((enum TParserNodeTypes)aRule.Type(), iSubRuleMatched); |
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286 //! performedMatch = ETrue; |
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287 } |
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288 return performedMatch; |
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289 } |
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290 |
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291 |
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292 /** Processes an EOr rule node. |
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293 |
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294 It is called by PerformRuleL(). |
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295 |
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296 @return ETrue if the function completed processing this node, otherwise EFalse |
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297 @param aRule The rule node being processed |
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298 @param aMatched On return, flag indicating if input stream matched the rule |
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299 */ |
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300 EXPORT_C TBool CBNFParser::OrL(CBNFNode& aRule, CFragmentedString::TStringMatch& /*aMatched*/) |
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301 // Handle Or rule |
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302 // We attempt to match the child rules of the Or node and stop when we have the first match. |
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303 // With the Or type rule each of the child rules are matched agaist the same bit of input |
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304 // stream. Before we start processing the first child rule we set a mark to the input stream |
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305 // and if a child rule doesn't match, we rollback the input stream to the mark and try |
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306 // to match the next child. |
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307 { |
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308 TBool performedMatch = EFalse; |
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309 CBNFNode* newRule = NULL; |
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310 // new to this Or, or returning from a sub match? |
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311 if (iSubRule) |
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312 { |
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313 if (!iSubRuleMatched) |
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314 { |
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315 newRule = REINTERPRET_CAST(CBNFNode*, iSubRule->NextSibling()); |
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316 } |
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317 EndConditional((enum TParserNodeTypes)aRule.Type(), iSubRuleMatched); |
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318 } |
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319 else |
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320 { |
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321 newRule = REINTERPRET_CAST(CBNFNode*, aRule.Child(0)); |
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322 iString.Mark(); // Mark can leave |
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323 } |
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324 if (newRule) |
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325 { |
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326 iRuleStack.PushL(newRule); |
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327 iSubRule = NULL; // going down |
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328 iString.ResetToMark(); |
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329 StartConditional((enum TParserNodeTypes)aRule.Type()); |
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330 } |
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331 else |
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332 { |
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333 performedMatch = ETrue; |
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334 if (!iSubRuleMatched) |
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335 iString.ResetToMark(); |
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336 iString.DeleteMark(); |
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337 } |
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338 return performedMatch; |
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339 } |
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340 |
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341 EXPORT_C TBool CBNFParser::OptionalL(CBNFNode& aRule, CFragmentedString::TStringMatch& aMatched) |
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342 // Handle Optional rule |
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343 // Process the subrule attached to the optional rule. |
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344 // An optional rule is always successfully processed regardless to success or failure of matching |
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345 // the subrule. This is because of the nature of the optional rule - the subrule here either may |
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346 // or may not be there. |
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347 { |
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348 TBool performedMatch = EFalse; |
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349 // new to this Optional, or returning from a sub match? |
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350 if (iSubRule) |
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351 { |
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352 performedMatch = ETrue; |
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353 aMatched = CFragmentedString::EMatch; |
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354 iOptionalMatched = iSubRuleMatched; |
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355 if (!iSubRuleMatched) |
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356 iString.ResetToMark(); |
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357 iString.DeleteMark(); |
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358 } |
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359 else |
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360 { |
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361 iString.Mark(); // Mark can leave |
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362 iRuleStack.PushL(REINTERPRET_CAST(CBNFNode*, aRule.Child(0))); |
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363 iSubRule = NULL; |
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364 } |
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365 return performedMatch; |
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366 } |
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367 |
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368 |
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369 |
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370 /** Processes an ENMore rule node. |
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371 |
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372 It is called by PerformRuleL(). |
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373 |
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374 @return ETrue if the function completed processing this node, otherwise EFalse |
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375 @param aRule The rule node being processed |
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376 @param aMatched On return, flag indicating if input stream matched the rule |
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377 */ |
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378 EXPORT_C TBool CBNFParser::NMoreL(CBNFNode& aRule, CFragmentedString::TStringMatch& aMatched) |
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379 // Handle NMore rule |
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380 // NMore rule implements the "multiplier" elements of BNF (* and +). |
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381 // We attempt to match the subrule and if it matches we try again until it doesn't match |
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382 // or we run into the upperlimit set to this rule. |
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383 // An NMore rule may contain lower and upper limits for the number of times the matching |
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384 // can or needs to be done. These are included as attributes to the NMore node. The NMore |
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385 // node also holds a counter attribute, which holds the amount of times this rule has been |
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386 // matched. |
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387 { |
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388 TBool performedMatch = EFalse; |
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389 // new to this NMore, or returning from a sub match? |
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390 if (iSubRule) |
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391 { |
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392 CNoDeleteAttributeT<TInt>* countAttribute = REINTERPRET_CAST(CNoDeleteAttributeT<TInt>*, aRule.Attribute(iMoreCount)); |
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393 CNoDeleteAttributeT<TInt>* maxCountAttribute = REINTERPRET_CAST(CNoDeleteAttributeT<TInt>*, aRule.Attribute(iMoreMaximum)); |
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394 |
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395 if (iSubRuleMatched) |
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396 countAttribute->SetAttribute(countAttribute->Attribute()+1); |
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397 else |
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398 { |
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399 performedMatch = ETrue; |
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400 CNoDeleteAttributeT<TInt>* minCountAttribute = REINTERPRET_CAST(CNoDeleteAttributeT<TInt>*, aRule.Attribute(iMoreMinimum)); |
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401 if ((minCountAttribute == NULL) || (countAttribute->Attribute() >= minCountAttribute->Attribute())) |
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402 aMatched = CFragmentedString::EMatch; |
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403 iString.ResetToMark(); |
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404 } |
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405 |
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406 if ((maxCountAttribute) && (countAttribute->Attribute() >= maxCountAttribute->Attribute())) |
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407 performedMatch = ETrue; |
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408 |
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409 iString.DeleteMark(); |
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410 } |
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411 else |
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412 { |
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413 aRule.DeleteAttribute(iMoreCount); |
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414 CNoDeleteAttributeT<TInt>* countAttribute = new (ELeave) CNoDeleteAttributeT<TInt>(0); |
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415 CleanupStack::PushL(countAttribute); |
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416 aRule.AddAttributeL(iMoreCount, countAttribute); |
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417 CleanupStack::Pop(); |
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418 } |
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419 if (!performedMatch) |
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420 { |
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421 iRuleStack.PushL(REINTERPRET_CAST(CBNFNode*, aRule.Child(0))); |
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422 iSubRule = NULL; |
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423 iString.Mark(); // Mark can leave |
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424 } |
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425 return performedMatch; |
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426 } |
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427 |
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428 /** Executes a pre-rule callback function. |
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429 |
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430 @param aRule Node specifying the callback |
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431 */ |
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432 EXPORT_C |
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433 void |
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434 CBNFParser::ExecutePreRuleCallbackL(CBNFNode& aRule) |
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435 { |
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436 CNoDeleteAttributeT<TRuleCallback*>* preRuleAttribute; |
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437 if ((preRuleAttribute= REINTERPRET_CAST(CNoDeleteAttributeT<TRuleCallback*>*, aRule.Attribute(iPreRuleCallback)))!=NULL) |
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438 (*preRuleAttribute->Attribute())(*this); |
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439 } |
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440 |
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441 /** Executes a post-rule callback function. |
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442 |
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443 @param aRule Node specifying the callback |
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444 */ |
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445 EXPORT_C |
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446 void |
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447 CBNFParser::ExecutePostRuleCallbackL(CBNFNode& aRule) |
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448 { |
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449 CNoDeleteAttributeT<TRuleCallback*>* postRuleAttribute; |
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450 if ((postRuleAttribute = REINTERPRET_CAST(CNoDeleteAttributeT<TRuleCallback*>*, aRule.Attribute(iPostRuleCallback)))!=NULL) |
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451 (*postRuleAttribute->Attribute())(*this); |
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452 } |
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453 |
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454 /** Handles a node in the rule tree. |
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455 |
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456 It calls the appropriate handler method for the rule type. |
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457 |
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458 @return ETrue if the function completed processing this node, otherwise EFalse |
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459 @param aRule Rule node |
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460 @param aMatched On return, flag indicating if input stream matched the rule |
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461 */ |
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462 EXPORT_C |
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463 TBool |
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464 CBNFParser::PerformRuleL(CBNFNode& aRule, CFragmentedString::TStringMatch& aMatched) |
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465 // Dispatches a rule node of given type to the appropriate handler |
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466 { |
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467 TBool performedMatch; |
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468 switch (aRule.Type()) |
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469 { |
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470 case EReference: |
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471 performedMatch = ReferenceL(aRule, aMatched); |
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472 break; |
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473 case EExact: |
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474 performedMatch = ExactL(aRule, aMatched); |
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475 break; |
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476 case ERange: |
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477 performedMatch = RangeL(aRule, aMatched); |
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478 break; |
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479 case ESelect: |
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480 performedMatch = SelectL(aRule, aMatched); |
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481 break; |
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482 case EWithout: |
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483 performedMatch = WithoutL(aRule, aMatched); |
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484 break; |
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485 case ERoot: |
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486 case EAnd: |
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487 performedMatch = AndL(aRule, aMatched); |
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488 break; |
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489 case EOr: |
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490 performedMatch = OrL(aRule, aMatched); |
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491 break; |
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492 case EOptional: |
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493 performedMatch = OptionalL(aRule, aMatched); |
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494 break; |
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495 case ENMore: |
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496 performedMatch = NMoreL(aRule, aMatched); |
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497 break; |
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498 case EIncomplete: |
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499 default: |
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500 __ASSERT_DEBUG(EFalse, User::Panic(_L("CBNFPARSE"), 1)); |
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501 // Oh dear an incomplete node in the rule tree. FAIL NOW!!! |
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502 performedMatch = ETrue; |
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503 aMatched = CFragmentedString::ENoMatch; |
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504 break; |
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505 } |
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506 return performedMatch; |
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507 } |
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508 |
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509 EXPORT_C TBool CBNFParser::ParseL() |
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510 // Performs the actual parsing. |
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511 // Consumes as much of the input data as it can using the iTree BNF tree. |
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512 // Whilst parsing the appropriate callbacks are invoked on the parsed rules allowing actions to be performed. |
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513 // Should the input data be fully consumed and the parser has not been notified that there is no more input data |
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514 // this method returns leaving the parser in a state waiting for more input. |
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515 { |
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516 iParsing = EActive; |
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517 while ((State() == EActive) && (!iRuleStack.IsEmpty())) |
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518 { |
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519 // find next rule |
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520 CBNFNode *currentRule = iRuleStack.Head(); |
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521 |
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522 // are we going up or down the tree? |
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523 if (iSubRule == NULL) |
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524 ExecutePreRuleCallbackL(*currentRule); |
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525 |
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526 if (PerformRuleL(*currentRule, iMatched)) |
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527 { |
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528 switch (iMatched) |
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529 { |
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530 case CFragmentedString::EMatch: |
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531 // we matched take ourselves off the stack |
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532 iRuleStack.Pop(); |
|
533 iSubRuleMatched = ETrue; |
|
534 iSubRule = currentRule; |
|
535 break; |
|
536 case CFragmentedString::EInsufficientData: |
|
537 // we ran out of data doing the match, should we try again later or is it a no match |
|
538 if (!iStringComplete) |
|
539 { |
|
540 iParsing= EStopped; |
|
541 break; |
|
542 } |
|
543 case CFragmentedString::ENoMatch: |
|
544 // we didn't match take ourselves off the stack |
|
545 iRuleStack.Pop(); |
|
546 iSubRuleMatched = EFalse; |
|
547 iSubRule = currentRule; |
|
548 break; |
|
549 default: |
|
550 // naughty, naughty. |
|
551 break; |
|
552 } |
|
553 if( iMatched != CFragmentedString::EInsufficientData || iStringComplete) |
|
554 ExecutePostRuleCallbackL(*currentRule); |
|
555 } |
|
556 // have we finished all the rules!?!?! |
|
557 if (iRuleStack.IsEmpty()) |
|
558 iParsing= EStopped; |
|
559 } |
|
560 return (iSubRuleMatched); |
|
561 } |
|
562 |
|
563 |
|
564 // |
|
565 // assist BNF tree building |
|
566 /** Creates a new rule tree root node. |
|
567 |
|
568 It creates a new single instance of CBNFNode as the root node of the rule tree. |
|
569 All the top-level rules are attached as attributes to this node. The root node |
|
570 should have single child node, which should be a reference to the logical root |
|
571 of the rule tree. This can be done be attaching the logical root rule as a component |
|
572 to the root rule. |
|
573 |
|
574 @return New rule tree root node |
|
575 */ |
|
576 EXPORT_C CBNFNode* CBNFParser::NewBNFL() |
|
577 // Generate a new ROOT node for a BNF tree. |
|
578 { |
|
579 return CBNFNode::NewL(ERoot); |
|
580 } |
|
581 |
|
582 /** Creates a new rule node and adds it to the root of the rule tree. |
|
583 |
|
584 This overload takes ownership of the node data. |
|
585 |
|
586 @return The newly created rule node in the rule tree |
|
587 @param aRootRule Pointer to the root BNF node, created with NewBNFL() |
|
588 @param aRuleName Reference to a string identifying this rule. The string is used to make references to this rule from other rule's subtrees. |
|
589 @param aRuleType Rule type |
|
590 @param aData Rule data pointer. This is used with EExact and ESelect type rules to match actual text strings. |
|
591 @param aPreRule Function pointer to a pre-rule function that gets called before the parser starts processing this rule and its children (i.e. the rule subtree). |
|
592 @param aPostRule Function pointer to a post-rule function that gets called after the parser has processed this rule and its subtree. |
|
593 */ |
|
594 EXPORT_C CBNFNode& CBNFParser::NewRuleL(CBNFNode* aRootRule, const TDesC& aRuleName, TParserNodeTypes aRuleType, HBufC* aData, TRuleCallback* aPreRule, TRuleCallback* aPostRule) |
|
595 // Add a new rule to the BNF tree, the new rule is given the name aRuleName (so it can be referred by another rule). |
|
596 // The parameter aData is used by the RuleTypes: Exact & Select. |
|
597 { |
|
598 // taken ownership of aData |
|
599 CleanupStack::PushL(aData); |
|
600 const HBufC* id = iLUT.Des2IDL(aRuleName); |
|
601 |
|
602 CBNFNode* terminal = REINTERPRET_CAST(CBNFNode*, aRootRule->Attribute(id)); |
|
603 |
|
604 if (terminal) |
|
605 terminal->SetType(aRuleType); |
|
606 else |
|
607 { |
|
608 terminal = CBNFNode::NewL(aRuleType); |
|
609 CleanupStack::PushL(terminal); |
|
610 aRootRule->AddAttributeL(id, terminal); |
|
611 CleanupStack::Pop(); |
|
612 } |
|
613 |
|
614 if (aData) |
|
615 terminal->SetDataL(aData); |
|
616 CleanupStack::Pop(); |
|
617 |
|
618 AddRuleCallbackL(*terminal, iPreRuleCallback, aPreRule); |
|
619 AddRuleCallbackL(*terminal, iPostRuleCallback, aPostRule); |
|
620 |
|
621 return *terminal; |
|
622 } |
|
623 |
|
624 /** Creates a new rule node and adds it to the root of the rule tree. |
|
625 |
|
626 This overload takes a reference to the node data instead of owning it. |
|
627 |
|
628 @return The newly created rule node in the rule tree |
|
629 @param aRootRule Pointer to the root BNF node, created with NewBNFL() |
|
630 @param aRuleName Reference to a string identifying this rule. The string is used to make references to this rule from other rule's subtrees. |
|
631 @param aRuleType Rule type |
|
632 @param aData Rule data pointer. This is used with EExact and ESelect type rules to match actual text strings. |
|
633 @param aPreRule Function pointer to a pre-rule function that gets called before the parser starts processing this rule and its children (i.e. the rule subtree). |
|
634 @param aPostRule Function pointer to a post-rule function that gets called after the parser has processed this rule and its subtree. |
|
635 */ |
|
636 EXPORT_C CBNFNode& CBNFParser::NewRuleL(CBNFNode* aRootRule, const TDesC& aRuleName, TParserNodeTypes aRuleType, const TDesC& aData, TRuleCallback* aPreRule, TRuleCallback* aPostRule) |
|
637 { |
|
638 return NewRuleL(aRootRule, aRuleName, aRuleType, aData.AllocL(), aPreRule, aPostRule); |
|
639 } |
|
640 |
|
641 /** Adds a callback to a rule. |
|
642 |
|
643 @param aRule The rule to which the callback is to be added |
|
644 @param aCallbackID Callback type: either CBNFNode::KPreRuleCallback() or CBNFNode::KPostRuleCallback() |
|
645 @param aCallback Callback function |
|
646 */ |
|
647 EXPORT_C void CBNFParser::AddRuleCallbackL(CBNFNode& aRule, const TDesC* aCallbackID, TRuleCallback* aCallback) |
|
648 { |
|
649 if (aCallback) |
|
650 { |
|
651 CNoDeleteAttributeT<TRuleCallback*>* ruleAttribute = new (ELeave) CNoDeleteAttributeT<TRuleCallback*>(aCallback); |
|
652 CleanupStack::PushL(ruleAttribute); |
|
653 aRule.AddAttributeL(aCallbackID, ruleAttribute); |
|
654 CleanupStack::Pop(); |
|
655 } |
|
656 } |
|
657 |
|
658 /** Creates a new reference rule node. |
|
659 |
|
660 @return The new reference rule node |
|
661 @param aRootRule Root node |
|
662 @param aRuleName Rule name |
|
663 */ |
|
664 EXPORT_C CBNFNode* CBNFParser::NewComponentL(CBNFNode* aRootRule, const TDesC& aRuleName) |
|
665 { |
|
666 CBNFNode *terminalNode = (CBNFNode*)aRootRule->Attribute(iLUT.Des2IDL(aRuleName)); |
|
667 if (terminalNode == NULL) |
|
668 terminalNode = &NewRuleL(aRootRule, aRuleName, EIncomplete, NULL, NULL, NULL); |
|
669 |
|
670 CBNFNode* rule = CBNFNode::NewL(EReference); |
|
671 CleanupStack::PushL(rule); |
|
672 CNoDeleteAttributeT<CBNFNode*>* attributeNode = new (ELeave) CNoDeleteAttributeT<CBNFNode*>(terminalNode); |
|
673 CleanupStack::PushL(attributeNode); |
|
674 rule->AddAttributeL(iReferenceString, attributeNode); |
|
675 CleanupStack::Pop(2); |
|
676 |
|
677 return rule; |
|
678 } |
|
679 |
|
680 |
|
681 /** Creates a new rule node, but does not add it to the tree. |
|
682 |
|
683 This overload sets no rule callbacks. |
|
684 |
|
685 @return The new rule node |
|
686 @param aRuleType Rule type |
|
687 @param aData Rule data reference. This is used with EExact and ESelect type rules to match actual text strings. |
|
688 */ |
|
689 EXPORT_C CBNFNode* CBNFParser::NewComponentL(TParserNodeTypes aRuleType, const TDesC& aData) |
|
690 // Adds a new rule component to the given ParentRule. |
|
691 { |
|
692 return NewComponentL(aRuleType, aData.AllocL()); |
|
693 } |
|
694 |
|
695 /** Creates a new rule node, but does not add it to the tree. |
|
696 |
|
697 This overload allows rule callbacks to be set. |
|
698 |
|
699 @return The new rule node |
|
700 @param aRuleType Rule type |
|
701 @param aData Rule data pointer. This is used with EExact and ESelect type rules to match actual text strings. |
|
702 @param aPreRule Function pointer to a pre-rule function that gets called before the parser starts processing this rule and its subtree. |
|
703 @param aPostRule The new rule node |
|
704 */ |
|
705 EXPORT_C CBNFNode* CBNFParser::NewComponentL(TParserNodeTypes aRuleType, HBufC* aData/*=NULL*/, TRuleCallback* aPreRule/*=NULL*/, TRuleCallback* aPostRule/*=NULL*/) |
|
706 { |
|
707 // taken ownership of aData |
|
708 CleanupStack::PushL(aData); |
|
709 CBNFNode* terminal = CBNFNode::NewL(aRuleType); |
|
710 CleanupStack::PushL(terminal); |
|
711 if (aData) |
|
712 terminal->SetDataL(aData); |
|
713 // correct cleanupstack |
|
714 CleanupStack::Pop(2); |
|
715 CleanupStack::PushL(terminal); |
|
716 |
|
717 AddRuleCallbackL(*terminal, iPreRuleCallback, aPreRule); |
|
718 AddRuleCallbackL(*terminal, iPostRuleCallback, aPostRule); |
|
719 |
|
720 CleanupStack::Pop(); //terminal |
|
721 return terminal; |
|
722 } |
|
723 |
|
724 |
|
725 /** Creates a new sub-rule, and makes it a child of a specified parent rule. |
|
726 |
|
727 This overload sets no rule callbacks. |
|
728 |
|
729 @return The new sub-rule node |
|
730 @param aParentRule The rule to the new sub-rule shall be added as a child |
|
731 @param aRuleType Rule type |
|
732 @param aData Rule data reference. This is used with EExact and ESelect type rules to match actual text strings. |
|
733 */ |
|
734 EXPORT_C CBNFNode& CBNFParser::NewComponentL(CBNFNode &aParentRule, TParserNodeTypes aRuleType, const TDesC& aData) |
|
735 // Adds a new rule component to the given ParentRule. |
|
736 { |
|
737 return NewComponentL(aParentRule, aRuleType, aData.AllocL()); |
|
738 } |
|
739 |
|
740 /** Creates a new sub-rule, and makes it a child of a specified parent rule. |
|
741 |
|
742 This overload sets rule callbacks. |
|
743 |
|
744 @return The new sub-rule node |
|
745 @param aParentRule The rule to the new sub-rule shall be added as a child |
|
746 @param aRuleType Rule type |
|
747 @param aData Rule data pointer. This is used with EExact and ESelect type rules to match actual text strings. |
|
748 @param aPreRule Function pointer to a pre-rule function that gets called before the parser starts processing this rule and its subtree. |
|
749 @param aPostRule Function pointer to a post-rule function that gets called after the parser has processed this rule and its subtree. |
|
750 */ |
|
751 EXPORT_C CBNFNode& CBNFParser::NewComponentL(CBNFNode &aParentRule, TParserNodeTypes aRuleType, HBufC* aData, TRuleCallback* aPreRule, TRuleCallback* aPostRule) |
|
752 { |
|
753 // take ownership of aData |
|
754 CleanupStack::PushL(aData); |
|
755 CBNFNode& terminal = REINTERPRET_CAST(CBNFNode&, aParentRule.AppendNodeL(aRuleType)); |
|
756 AddRuleCallbackL(terminal, iPreRuleCallback, aPreRule); |
|
757 AddRuleCallbackL(terminal, iPostRuleCallback, aPostRule); |
|
758 |
|
759 if (aData) |
|
760 terminal.SetDataL(aData); |
|
761 CleanupStack::Pop(); |
|
762 |
|
763 return terminal; |
|
764 } |
|
765 |
|
766 |
|
767 /** Creates a new reference rule node, and adds it as a child of the specified parent. |
|
768 |
|
769 Note that the function succeeds even if the target rule aRuleName does not yet exist. |
|
770 |
|
771 @return The new reference rule node |
|
772 @param aRootRule Root node: the function needs this to find the target rule identified by aRuleName |
|
773 @param aParentRule Parent rule to which to attach the new rule as a child |
|
774 @param aRuleName The name of the rule that the new node refers to |
|
775 */ |
|
776 EXPORT_C CBNFNode& CBNFParser::NewComponentL(CBNFNode* aRootRule, CBNFNode &aParentRule, const TDesC& aRuleName) |
|
777 { |
|
778 CBNFNode *terminalNode = (CBNFNode*)aRootRule->Attribute(iLUT.Des2IDL(aRuleName)); |
|
779 if (terminalNode == NULL) |
|
780 terminalNode = &NewRuleL(aRootRule, aRuleName, EIncomplete, NULL, NULL, NULL); |
|
781 |
|
782 CBNFNode& rule = REINTERPRET_CAST(CBNFNode&, aParentRule.AppendNodeL(EReference)); |
|
783 CNoDeleteAttributeT<CBNFNode*>* attributeNode = new (ELeave) CNoDeleteAttributeT<CBNFNode*>(terminalNode); |
|
784 CleanupStack::PushL(attributeNode); |
|
785 rule.AddAttributeL(iReferenceString, attributeNode); |
|
786 CleanupStack::Pop(); |
|
787 |
|
788 return rule; |
|
789 } |
|
790 |
|
791 /** Adds an additional attribute to an existing rule node. |
|
792 |
|
793 For example, this is used with range rules, which specify the range boundaries using start and end attributes. |
|
794 |
|
795 @param aRule Rule node on which to set the attribute |
|
796 @param aAttribute Attribute type |
|
797 @param aInt Attribute value |
|
798 */ |
|
799 EXPORT_C void CBNFParser::AddComponentAttributeL(CBNFNode& aRule, CBNFNodeAttributeType aAttribute, TInt aInt) |
|
800 // Adds a restriction to a rule component, this is used for instance with Range restrictions (Start/End) |
|
801 { |
|
802 CNoDeleteAttributeT<TInt>* aTIntAttribute = new (ELeave) CNoDeleteAttributeT<TInt>(aInt); |
|
803 CleanupStack::PushL(aTIntAttribute); |
|
804 aRule.AddAttributeL(aAttribute, aTIntAttribute); |
|
805 CleanupStack::Pop(); |
|
806 } |
|
807 |
|
808 /** Inserts a mark to the current position of the stream being processed. |
|
809 |
|
810 Adding a mark is a very common callback operation before starting to process a rule, so the method is provided by the parser. |
|
811 |
|
812 @param aParser Parser processing the stream |
|
813 */ |
|
814 EXPORT_C void CBNFParser::MarkCallback(CBNFParser& aParser) |
|
815 // Provide a very common preaction callback to mark the input stream before the next rule attempts to parse it. |
|
816 {// static |
|
817 aParser.Mark(); // Mark can leave |
|
818 } |
|
819 |
|
820 |
|
821 // |
|
822 // Data Provider access |
|
823 /** Called by the data provider to add data for the parser to process. |
|
824 |
|
825 This implements MDataProviderObserver::ProcessDataL(). |
|
826 |
|
827 @param aData The data to process |
|
828 */ |
|
829 EXPORT_C void CBNFParser::ProcessDataL(HBufC8& aData) |
|
830 // Add new data as the input to the parser, ownership is taken of the aData. |
|
831 { |
|
832 HBufC* newData = HBufC::NewL(aData.Length()); |
|
833 newData->Des().Copy(aData.Des()); |
|
834 |
|
835 iString.AddStringL(newData); |
|
836 |
|
837 ParseL(); |
|
838 } |
|
839 |
|
840 /** Called by the data provider to report its status to its observer. |
|
841 |
|
842 This implements MDataProviderObserver::SetStatus(). |
|
843 |
|
844 @param aStatusCode Status code |
|
845 */ |
|
846 EXPORT_C void CBNFParser::SetStatus(TInt aStatusCode) |
|
847 // Notify the parser that there is no more (new) input data to be added/parsed. |
|
848 { |
|
849 if (aStatusCode == EPluginComplete) |
|
850 { |
|
851 // No more data will be pushed at us |
|
852 // so do what we need to finish and set our |
|
853 // status |
|
854 iStringComplete = ETrue; |
|
855 } |
|
856 } |
|
857 |
|
858 EXPORT_C void CBNFParser::SetDocumentTypeL(const TDesC& /*aDocType*/) |
|
859 { |
|
860 } |
|
861 |
|
862 EXPORT_C void CBNFParser::SetDocumentTypeL(const TDesC&, const TDesC&) |
|
863 { |
|
864 } |
|
865 |
|
866 EXPORT_C void CBNFParser::SetDataExpected(TInt) |
|
867 { |
|
868 } |
|
869 |
|
870 EXPORT_C void CBNFParser::SetBaseUriL(const TDesC* /*aBaseUri*/) |
|
871 { |
|
872 } |
|
873 |
|
874 /** Notifies the parser that all the data has been passed in. |
|
875 |
|
876 It causes the parser to parse any of the input stream not already parsed. |
|
877 */ |
|
878 EXPORT_C void CBNFParser::CommitL() |
|
879 { |
|
880 if (iStringComplete) |
|
881 ParseL(); |
|
882 } |
|
883 |
|
884 EXPORT_C CBNFNode* CBNFParser::TreeL() |
|
885 { |
|
886 return NULL; |
|
887 } |
|
888 |
|
889 EXPORT_C void CBNFParser::StartConditional(TParserNodeTypes /*aRuleType*/) |
|
890 { |
|
891 } |
|
892 |
|
893 EXPORT_C void CBNFParser::EndConditional(TParserNodeTypes /*aRuleType*/, TBool /*aSuccess*/) |
|
894 { |
|
895 } |
|
896 |
|
897 |
|
898 // Provide an implementation for the interface class |
|
899 EXPORT_C void CBNFParser::MDataProviderObserverReserved1() |
|
900 { |
|
901 User::Panic(_L("Reserved"),KErrNotSupported); |
|
902 } |
|
903 |
|
904 EXPORT_C void CBNFParser::MDataProviderObserverReserved2() |
|
905 { |
|
906 User::Panic(_L("Reserved"),KErrNotSupported); |
|
907 } |