//-----------------------------------------------------------------------------
//
// flagAcceptingStates Identify accepting states.
// First get a list of all of the end marker nodes.
// Then, for each state s,
// if s contains one of the end marker nodes in its list of tree positions then
// s is an accepting state.
//
//-----------------------------------------------------------------------------
void RBBITableBuilder::flagAcceptingStates() {
if (U_FAILURE(*fStatus)) {
return;
}
UVector endMarkerNodes(*fStatus);
RBBINode *endMarker;
int32_t i;
int32_t n;
if (U_FAILURE(*fStatus)) {
return;
}
fTree->findNodes(&endMarkerNodes, RBBINode::endMark, *fStatus);
if (U_FAILURE(*fStatus)) {
return;
}
for (i=0; i<endMarkerNodes.size(); i++) {
endMarker = (RBBINode *)endMarkerNodes.elementAt(i);
for (n=0; n<fDStates->size(); n++) {
RBBIStateDescriptor *sd = (RBBIStateDescriptor *)fDStates->elementAt(n);
if (sd->fPositions->indexOf(endMarker) >= 0) {
// Any non-zero value for fAccepting means this is an accepting node.
// The value is what will be returned to the user as the break status.
// If no other value was specified, force it to -1.
if (sd->fAccepting==0) {
// State hasn't been marked as accepting yet. Do it now.
sd->fAccepting = endMarker->fVal;
if (sd->fAccepting == 0) {
sd->fAccepting = -1;
}
}
if (sd->fAccepting==-1 && endMarker->fVal != 0) {
// Both lookahead and non-lookahead accepting for this state.
// Favor the look-ahead. Expedient for line break.
// TODO: need a more elegant resolution for conflicting rules.
sd->fAccepting = endMarker->fVal;
}
// implicit else:
// if sd->fAccepting already had a value other than 0 or -1, leave it be.
// If the end marker node is from a look-ahead rule, set
// the fLookAhead field or this state also.
if (endMarker->fLookAheadEnd) {
// TODO: don't change value if already set?
// TODO: allow for more than one active look-ahead rule in engine.
// Make value here an index to a side array in engine?
sd->fLookAhead = sd->fAccepting;
}
}
}
}
}
//-----------------------------------------------------------------------------
//
// flagAcceptingStates Identify accepting states.
// First get a list of all of the end marker nodes.
// Then, for each state s,
// if s contains one of the end marker nodes in its list of tree positions then
// s is an accepting state.
//
//-----------------------------------------------------------------------------
void RBBITableBuilder::flagAcceptingStates() {
if (U_FAILURE(*fStatus)) {
return;
}
UVector endMarkerNodes(*fStatus);
RBBINode *endMarker;
int32_t i;
int32_t n;
if (U_FAILURE(*fStatus)) {
return;
}
fTree->findNodes(&endMarkerNodes, RBBINode::endMark, *fStatus);
if (U_FAILURE(*fStatus)) {
return;
}
for (i=0; i<endMarkerNodes.size(); i++) {
endMarker = (RBBINode *)endMarkerNodes.elementAt(i);
for (n=0; n<fDStates->size(); n++) {
RBBIStateDescriptor *sd = (RBBIStateDescriptor *)fDStates->elementAt(n);
if (sd->fPositions->indexOf(endMarker) >= 0) {
// Any non-zero value for fAccepting means this is an accepting node.
// The value is what will be returned to the user as the break status.
// If no other value was specified, force it to -1.
sd->fAccepting = endMarker->fVal;
if (sd->fAccepting == 0) {
sd->fAccepting = -1;
}
// If the end marker node is from a look-ahead rule, set
// the fLookAhead field or this state also.
if (endMarker->fLookAheadEnd) {
sd->fLookAhead = sd->fAccepting;
}
}
}
}
}
//-----------------------------------------------------------------------------
//
// calcChainedFollowPos. Modify the previously calculated followPos sets
// to implement rule chaining. NOT described by Aho
//
//-----------------------------------------------------------------------------
void RBBITableBuilder::calcChainedFollowPos(RBBINode *tree) {
UVector endMarkerNodes(*fStatus);
UVector leafNodes(*fStatus);
int32_t i;
if (U_FAILURE(*fStatus)) {
return;
}
// get a list of all endmarker nodes.
tree->findNodes(&endMarkerNodes, RBBINode::endMark, *fStatus);
// get a list all leaf nodes
tree->findNodes(&leafNodes, RBBINode::leafChar, *fStatus);
if (U_FAILURE(*fStatus)) {
return;
}
// Get all nodes that can be the start a match, which is FirstPosition()
// of the portion of the tree corresponding to user-written rules.
// See the tree description in bofFixup().
RBBINode *userRuleRoot = tree;
if (fRB->fSetBuilder->sawBOF()) {
userRuleRoot = tree->fLeftChild->fRightChild;
}
U_ASSERT(userRuleRoot != NULL);
UVector *matchStartNodes = userRuleRoot->fFirstPosSet;
// Iteratate over all leaf nodes,
//
int32_t endNodeIx;
int32_t startNodeIx;
for (endNodeIx=0; endNodeIx<leafNodes.size(); endNodeIx++) {
RBBINode *tNode = (RBBINode *)leafNodes.elementAt(endNodeIx);
RBBINode *endNode = NULL;
// Identify leaf nodes that correspond to overall rule match positions.
// These include an endMarkerNode in their followPos sets.
for (i=0; i<endMarkerNodes.size(); i++) {
if (tNode->fFollowPos->contains(endMarkerNodes.elementAt(i))) {
endNode = tNode;
break;
}
}
if (endNode == NULL) {
// node wasn't an end node. Try again with the next.
continue;
}
// We've got a node that can end a match.
// Line Break Specific hack: If this node's val correspond to the $CM char class,
// don't chain from it.
// TODO: Add rule syntax for this behavior, get specifics out of here and
// into the rule file.
if (fRB->fLBCMNoChain) {
UChar32 c = this->fRB->fSetBuilder->getFirstChar(endNode->fVal);
if (c != -1) {
// c == -1 occurs with sets containing only the {eof} marker string.
ULineBreak cLBProp = (ULineBreak)u_getIntPropertyValue(c, UCHAR_LINE_BREAK);
if (cLBProp == U_LB_COMBINING_MARK) {
continue;
}
}
}
// Now iterate over the nodes that can start a match, looking for ones
// with the same char class as our ending node.
RBBINode *startNode;
for (startNodeIx = 0; startNodeIx<matchStartNodes->size(); startNodeIx++) {
startNode = (RBBINode *)matchStartNodes->elementAt(startNodeIx);
if (startNode->fType != RBBINode::leafChar) {
continue;
}
if (endNode->fVal == startNode->fVal) {
// The end val (character class) of one possible match is the
// same as the start of another.
// Add all nodes from the followPos of the start node to the
// followPos set of the end node, which will have the effect of
// letting matches transition from a match state at endNode
// to the second char of a match starting with startNode.
setAdd(endNode->fFollowPos, startNode->fFollowPos);
}
}
}
}
