//Impletment methods of Scanner class
ScannerClass::ScannerClass(){
buildStateTable();
}
//-----------------------------------------------------------------------------
//
// RBBITableBuilder::build - This is the main function for building the DFA state transtion
// table from the RBBI rules parse tree.
//
//-----------------------------------------------------------------------------
void RBBITableBuilder::build() {
if (U_FAILURE(*fStatus)) {
return;
}
// If there were no rules, just return. This situation can easily arise
// for the reverse rules.
if (fTree==NULL) {
return;
}
//
// Walk through the tree, replacing any references to $variables with a copy of the
// parse tree for the substition expression.
//
fTree = fTree->flattenVariables();
#ifdef RBBI_DEBUG
if (fRB->fDebugEnv && uprv_strstr(fRB->fDebugEnv, "ftree")) {
RBBIDebugPuts("Parse tree after flattening variable references.");
fTree->printTree(TRUE);
}
#endif
//
// If the rules contained any references to {bof}
// add a {bof} <cat> <former root of tree> to the
// tree. Means that all matches must start out with the
// {bof} fake character.
//
if (fRB->fSetBuilder->sawBOF()) {
RBBINode *bofTop = new RBBINode(RBBINode::opCat);
RBBINode *bofLeaf = new RBBINode(RBBINode::leafChar);
bofTop->fLeftChild = bofLeaf;
bofTop->fRightChild = fTree;
bofLeaf->fParent = bofTop;
bofLeaf->fVal = 2; // Reserved value for {bof}.
fTree = bofTop;
}
//
// Add a unique right-end marker to the expression.
// Appears as a cat-node, left child being the original tree,
// right child being the end marker.
//
RBBINode *cn = new RBBINode(RBBINode::opCat);
cn->fLeftChild = fTree;
fTree->fParent = cn;
cn->fRightChild = new RBBINode(RBBINode::endMark);
cn->fRightChild->fParent = cn;
fTree = cn;
//
// Replace all references to UnicodeSets with the tree for the equivalent
// expression.
//
fTree->flattenSets();
#ifdef RBBI_DEBUG
if (fRB->fDebugEnv && uprv_strstr(fRB->fDebugEnv, "stree")) {
RBBIDebugPuts("Parse tree after flattening Unicode Set references.");
fTree->printTree(TRUE);
}
#endif
//
// calculate the functions nullable, firstpos, lastpos and followpos on
// nodes in the parse tree.
// See the alogrithm description in Aho.
// Understanding how this works by looking at the code alone will be
// nearly impossible.
//
calcNullable(fTree);
calcFirstPos(fTree);
calcLastPos(fTree);
calcFollowPos(fTree);
if (fRB->fDebugEnv && uprv_strstr(fRB->fDebugEnv, "pos")) {
RBBIDebugPuts("\n");
printPosSets(fTree);
}
//
// For "chained" rules, modify the followPos sets
//
if (fRB->fChainRules) {
calcChainedFollowPos(fTree);
}
//
// BOF (start of input) test fixup.
//
if (fRB->fSetBuilder->sawBOF()) {
bofFixup();
}
//
// Build the DFA state transition tables.
//
buildStateTable();
flagAcceptingStates();
flagLookAheadStates();
flagTaggedStates();
//
// Update the global table of rule status {tag} values
// The rule builder has a global vector of status values that are common
// for all tables. Merge the ones from this table into the global set.
//
mergeRuleStatusVals();
if (fRB->fDebugEnv && uprv_strstr(fRB->fDebugEnv, "states")) {printStates();};
}
void
ZDriver::writeParserUtil( std::ostream &out )
{
emitFuncBreak( out );
out << "void " << myPimplName << "::popStack( void )" << endl();
out << "{" << endl();
out << " callDtor( myStack.top().first.second, myStack.top().second );"
<< endl();
out << " myStack.pop();" << endl();
out << "}" << endl();
emitFuncBreak( out );
out << "ParserAct " << myPimplName
<< "::findParserAction( int &newVal, int tok )" << endl();
out << "{" << endl();
out << " int stateNum;" << endl();
out << " ParserAct retval = PA_NOP;" << endl();
out << " bool found = false;" << endl();
out << endl();
out << " stateNum = myStack.empty() ? 0 : myStack.top().first.first;"
<< endl();
out << " ActionMap::iterator i = myStates[stateNum].find( tok );"
<< endl();
out << " if ( tok >= 0 && tok <= "
<< SymbolTable::get()->getNumSymbols() << " )" << endl();
out << " {" << endl();
out << " if ( i != myStates[stateNum].end() )" << endl();
out << " {" << endl();
out << " retval = (*i).second.first;" << endl();
out << " newVal = (*i).second.second;" << endl();
out << " found = true;" << endl();
out << " }" << endl();
out << " }" << endl();
out << " else if ( ! myStates[stateNum].empty() )" << endl();
out << " {" << endl();
out << " retval = PA_NOP;" << endl();
out << " newVal = 0;" << endl();
out << " found = true;" << endl();
out << " }" << endl();
out << endl();
out << " if ( ! found )" << endl();
out << " {" << endl();
out << " retval = myStateDefaultActions[stateNum].first;" << endl();
out << " newVal = myStateDefaultActions[stateNum].second;" << endl();
out << " }" << endl();
out << " return retval;" << endl();
out << "}" << endl();
emitFuncBreak( out );
writeStateTable( out );
writeRuleTable( out );
emitFuncBreak( out );
out << "void " << myPimplName << "::initTables( void )" << endl();
out << "{" << endl();
buildStateTable( out );
buildRuleTable( out );
out << "}" << endl();
}
