protected internal virtual IParseTree MatchImpl(IParseTree tree, IParseTree patternTree, MultiMap<string, IParseTree> labels)
{
if (tree == null)
{
throw new ArgumentException("tree cannot be null");
}
if (patternTree == null)
{
throw new ArgumentException("patternTree cannot be null");
}
// x and <ID>, x and y, or x and x; or could be mismatched types
if (tree is ITerminalNode && patternTree is ITerminalNode)
{
ITerminalNode t1 = (ITerminalNode)tree;
ITerminalNode t2 = (ITerminalNode)patternTree;
IParseTree mismatchedNode = null;
// both are tokens and they have same type
if (t1.Symbol.Type == t2.Symbol.Type)
{
if (t2.Symbol is TokenTagToken)
{
// x and <ID>
TokenTagToken tokenTagToken = (TokenTagToken)t2.Symbol;
// track label->list-of-nodes for both token name and label (if any)
labels.Map(tokenTagToken.TokenName, tree);
if (tokenTagToken.Label != null)
{
labels.Map(tokenTagToken.Label, tree);
}
}
else
{
if (t1.GetText().Equals(t2.GetText(), StringComparison.Ordinal))
{
}
else
{
// x and x
// x and y
if (mismatchedNode == null)
{
mismatchedNode = t1;
}
}
}
}
else
{
if (mismatchedNode == null)
{
mismatchedNode = t1;
}
}
return mismatchedNode;
}
if (tree is ParserRuleContext && patternTree is ParserRuleContext)
{
ParserRuleContext r1 = (ParserRuleContext)tree;
ParserRuleContext r2 = (ParserRuleContext)patternTree;
IParseTree mismatchedNode = null;
// (expr ...) and <expr>
RuleTagToken ruleTagToken = GetRuleTagToken(r2);
if (ruleTagToken != null)
{
if (r1.RuleIndex == r2.RuleIndex)
{
// track label->list-of-nodes for both rule name and label (if any)
labels.Map(ruleTagToken.RuleName, tree);
if (ruleTagToken.Label != null)
{
labels.Map(ruleTagToken.Label, tree);
}
}
else
{
if (mismatchedNode == null)
{
mismatchedNode = r1;
}
}
return mismatchedNode;
}
// (expr ...) and (expr ...)
if (r1.ChildCount != r2.ChildCount)
{
if (mismatchedNode == null)
{
mismatchedNode = r1;
}
return mismatchedNode;
}
int n = r1.ChildCount;
for (int i = 0; i < n; i++)
{
IParseTree childMatch = MatchImpl(r1.GetChild(i), patternTree.GetChild(i), labels);
if (childMatch != null)
{
return childMatch;
}
}
return mismatchedNode;
}
// if nodes aren't both tokens or both rule nodes, can't match
return tree;
}
