/*!
* \brief Parse an And expression
* \param tokenList The list of tokens
* \return Return the tree corresponding to the expression or null if the parsing fail.
*/
public TreeNode <PromoterNodeData> ParseAndExpr(LinkedList <PromoterLexer.Token> tokenList)
{
PromoterNodeData data = new PromoterNodeData();
TreeNode <PromoterNodeData> left = null;
TreeNode <PromoterNodeData> right = null;
int restoreStatus;
restoreStatus = getRestoreListStatus();
if ((left = ParseParExpr(tokenList)) == null)
{
restoreListState(tokenList, restoreStatus);
return(null);
}
if (tokenList.First().token == PromoterLexer.eToken.OP_AND)
{
PromoterLexer.Token tok = tokenList.First();
popToken(tokenList);
if ((right = ParseAndExpr(tokenList)) == null)
{
restoreListState(tokenList, restoreStatus);
Debug.Log("Syntax error : bad AND expr");
return(null);
}
data.token = PromoterParser.eNodeType.AND;
data.value = tok.c;
return(new TreeNode <PromoterNodeData>(data, left, right));
}
else
{
return(left);
}
}
/*!
* \brief Restore last token that were poped in the given list
* \param list The list where to restore token
*/
public void restoreToken(LinkedList <PromoterLexer.Token> list)
{
PromoterLexer.Token tok = _restoreList.First();
_restoreList.RemoveFirst();
list.AddFirst(tok);
_restoreStatus -= 1;
}
/*!
* \brief Parse a Not expression
* \param tokenList The list of tokens
* \return Return the tree corresponding to the expression or null if the parsing fail.
*/
public TreeNode <PromoterNodeData> ParseNotExpr(LinkedList <PromoterLexer.Token> tokenList)
{
PromoterNodeData data = new PromoterNodeData();
TreeNode <PromoterNodeData> node = new TreeNode <PromoterNodeData>(data);
int restoreStatus;
restoreStatus = getRestoreListStatus();
if (tokenList.First().token == PromoterLexer.eToken.OP_NOT)
{
PromoterLexer.Token tok = tokenList.First();
popToken(tokenList);
if ((node = ParseOperandExpr(tokenList)) == null)
{
restoreListState(tokenList, restoreStatus);
Debug.Log("Syntax Error: Bad Not Expr");
return(null);
}
data.token = PromoterParser.eNodeType.NOT;
data.value = tok.c;
return(new TreeNode <PromoterNodeData>(data, node));
}
return(ParseOperandExpr(tokenList));
}
