// -----------------------------------------------------------------------------
//
// bofFixup. Fixup for state tables that include {bof} beginning of input
// testing.
// Do an swizzle similar to chaining, modifying the followPos set of
// the bofNode to include the followPos nodes from other {bot} nodes
// scattered through the tree.
//
// This function has much in common with calcChainedFollowPos().
//
// -----------------------------------------------------------------------------
internal void BofFixup()
{
//
// The parse tree looks like this ...
// fTree root --. <cat>
// / \
// <cat> <#end node>
// / \
// <bofNode> rest
// of tree
//
// We will be adding things to the followPos set of the <bofNode>
//
RBBINode bofNode = fRB.fTreeRoots[fRootIx].fLeftChild.fLeftChild;
IBM.ICU.Impl.Assert.Assrt(bofNode.fType == IBM.ICU.Text.RBBINode.leafChar);
IBM.ICU.Impl.Assert.Assrt(bofNode.fVal == 2);
// Get all nodes that can be the start a match of the user-written rules
// (excluding the fake bofNode)
// We want the nodes that can start a match in the
// part labeled "rest of tree"
//
ILOG.J2CsMapping.Collections.ISet matchStartNodes = fRB.fTreeRoots[fRootIx].fLeftChild.fRightChild.fFirstPosSet;
IIterator startNodeIt = new ILOG.J2CsMapping.Collections.IteratorAdapter(matchStartNodes.GetEnumerator());
while (startNodeIt.HasNext())
{
RBBINode startNode = (RBBINode)startNodeIt.Next();
if (startNode.fType != IBM.ICU.Text.RBBINode.leafChar)
{
continue;
}
if (startNode.fVal == bofNode.fVal)
{
// We found a leaf node corresponding to a {bof} that was
// explicitly written into a rule.
// Add everything from the followPos set of this node to the
// followPos set of the fake bofNode at the start of the tree.
//
ILOG.J2CsMapping.Collections.Generics.Collections.AddAll(startNode.fFollowPos, bofNode.fFollowPos);
}
}
}
// -----------------------------------------------------------------------------
//
// calcFollowPos. Impossible to explain succinctly. See Aho, section 3.9
//
// -----------------------------------------------------------------------------
internal void CalcFollowPos(RBBINode n)
{
if (n == null || n.fType == IBM.ICU.Text.RBBINode.leafChar ||
n.fType == IBM.ICU.Text.RBBINode.endMark)
{
return;
}
CalcFollowPos(n.fLeftChild);
CalcFollowPos(n.fRightChild);
// Aho rule #1
if (n.fType == IBM.ICU.Text.RBBINode.opCat)
{
RBBINode i; // is 'i' in Aho's description
ILOG.J2CsMapping.Collections.ISet LastPosOfLeftChild = n.fLeftChild.fLastPosSet;
IIterator ix = new ILOG.J2CsMapping.Collections.IteratorAdapter(LastPosOfLeftChild.GetEnumerator());
while (ix.HasNext())
{
i = (RBBINode)ix.Next();
ILOG.J2CsMapping.Collections.Generics.Collections.AddAll(n.fRightChild.fFirstPosSet, i.fFollowPos);
}
}
// Aho rule #2
if (n.fType == IBM.ICU.Text.RBBINode.opStar || n.fType == IBM.ICU.Text.RBBINode.opPlus)
{
RBBINode i_0; // again, n and i are the names from Aho's description.
IIterator ix_1 = new ILOG.J2CsMapping.Collections.IteratorAdapter(n.fLastPosSet.GetEnumerator());
while (ix_1.HasNext())
{
i_0 = (RBBINode)ix_1.Next();
ILOG.J2CsMapping.Collections.Generics.Collections.AddAll(n.fFirstPosSet, i_0.fFollowPos);
}
}
}
// -----------------------------------------------------------------------------
//
// calcChainedFollowPos. Modify the previously calculated followPos sets
// to implement rule chaining. NOT described by Aho
//
// -----------------------------------------------------------------------------
internal void CalcChainedFollowPos(RBBINode tree)
{
IList endMarkerNodes = new ArrayList();
IList leafNodes = new ArrayList();
// get a list of all endmarker nodes.
tree.FindNodes(endMarkerNodes, IBM.ICU.Text.RBBINode.endMark);
// get a list all leaf nodes
tree.FindNodes(leafNodes, IBM.ICU.Text.RBBINode.leafChar);
// 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;
}
IBM.ICU.Impl.Assert.Assrt(userRuleRoot != null);
ILOG.J2CsMapping.Collections.ISet matchStartNodes = userRuleRoot.fFirstPosSet;
// Iteratate over all leaf nodes,
//
IIterator endNodeIx = new ILOG.J2CsMapping.Collections.IteratorAdapter(leafNodes.GetEnumerator());
while (endNodeIx.HasNext())
{
RBBINode tNode = (RBBINode)endNodeIx.Next();
RBBINode endNode = null;
// Identify leaf nodes that correspond to overall rule match
// positions.
// These include an endMarkerNode in their followPos sets.
IIterator i = new ILOG.J2CsMapping.Collections.IteratorAdapter(endMarkerNodes.GetEnumerator());
while (i.HasNext())
{
RBBINode endMarkerNode = (RBBINode)i.Next();
if (ILOG.J2CsMapping.Collections.Collections.Contains(endMarkerNode, tNode.fFollowPos))
{
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)
{
int c = this.fRB.fSetBuilder.GetFirstChar(endNode.fVal);
if (c != -1)
{
// c == -1 occurs with sets containing only the {eof} marker
// string.
int cLBProp = IBM.ICU.Lang.UCharacter.GetIntPropertyValue(c,
IBM.ICU.Lang.UProperty_Constants.LINE_BREAK);
if (cLBProp == IBM.ICU.Lang.UCharacter.LineBreak.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;
IIterator startNodeIx = new ILOG.J2CsMapping.Collections.IteratorAdapter(matchStartNodes.GetEnumerator());
while (startNodeIx.HasNext())
{
startNode = (RBBINode)startNodeIx.Next();
if (startNode.fType != IBM.ICU.Text.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.
ILOG.J2CsMapping.Collections.Generics.Collections.AddAll(startNode.fFollowPos, endNode.fFollowPos);
}
}
}
}
