private void _andTerm()
{
_orTerm();
if (next.GetType() == typeof(AndToken))
{
newSimpleTree(new Node(_tokens.getNextToken()), branchesStack.Pop());
next = _tokens.PeekToken();
_andTerm();
}
else
return;
}
public Parser(Tokens tokens)
{
branchesStack = new Stack<Node>();
BinaryTree = new BinaryTreeImp();
_tokens = tokens;
next = _tokens.PeekToken();
if (next.ToString() == "(")
_query();
else //NOTE: if the first token is not a parenthesis then all tokens are treated as word tokens, not logic tokens or others
_buildTreeWordsOnly();
}
//the evaluater uses Reverse Polish Notation
public void evaluate(Token token)
{
IEnumerable<string> newLinkSet = null;
if (stack.Count >= 2)
{
if (token.GetType() == typeof(AndToken))
{
newLinkSet = stack.Pop().Intersect(stack.Pop());
}
if (token.GetType() == typeof(OrToken))
{
newLinkSet = stack.Pop().Union(stack.Pop());
}
if (token.GetType() == typeof(AndNotToken))
{
var excluded = stack.Pop();
var included = stack.Pop();
newLinkSet = included.Except(excluded);
}
stack.Push(newLinkSet);
}
}
public Node(Token token)
{
this.token = token;
left = null;
right = null;
}
private void _term()
{
if (next.GetType() == typeof(ParenthesisBeginToken) && (!_tokens.isEmpty()))
{
Token token = _tokens.getNextToken();
BinaryTree = new BinaryTreeImp(); //reset the binary tree to ready for a new branch build
next = _tokens.PeekToken();
_term();
}
if (next.GetType() == typeof(ParenthesisEndToken) && (!_tokens.isEmpty()))
{
Token token = _tokens.getNextToken();
_buildTreeFromAllRemainingBranches();
if (_tokens.isEmpty())
return;
next = _tokens.PeekToken();
_term();
}
if (next.GetType() == typeof(WordToken) && (!_tokens.isEmpty()))
{
Token wordToken = _tokens.getNextToken();
branchesStack.Push(new Node(wordToken));
next = _tokens.PeekToken();
_term();
}
if (_tokens.isEmpty())
return;
}
public void AddToken(Token token)
{
_tokenQueue.Enqueue(token);
}
