private IExpressionNode ParseBinaryExpression(IExpressionNode left, IExpressionNode right, TokenType token, bool isInternalCall)
{
bool returnEmptyNode = false;
List<IExpressionNode> nodes = null;
List<TokenType> tokens = null;
if (isInternalCall)
{
nodes = _nodes;
tokens = _tokens;
returnEmptyNode = nodes != null;
}
if (!IsBinaryToken() && !returnEmptyNode)
return new BinaryExpressionNode(left, right, token);
if (nodes == null)
nodes = new List<IExpressionNode>();
if (tokens == null)
tokens = new List<TokenType>();
nodes.Add(left);
nodes.Add(right);
tokens.Add(token);
var oldTokens = _tokens;
var oldNodes = _nodes;
_nodes = nodes;
_tokens = tokens;
try
{
do
{
token = Tokenizer.Token;
if (!BinaryOperationTokens.ContainsKey(token))
token = BinaryOperationAliases[Tokenizer.Value];
NextToken(true);
tokens.Add(token);
nodes.AddIfNotNull(ParseUnary());
} while (IsBinaryToken());
}
finally
{
_tokens = oldTokens;
_nodes = oldNodes;
}
if (returnEmptyNode)
return null;
int index = GetMaxPriorityTokenIndex(tokens);
while (index != -1)
{
token = tokens[index];
tokens.RemoveAt(index);
nodes[index] = new BinaryExpressionNode(nodes[index], nodes[index + 1], token);
nodes.RemoveAt(index + 1);
index = GetMaxPriorityTokenIndex(tokens);
}
return nodes[0];
}
protected virtual IExpressionNode ParseBinaryExpression(IExpressionNode left = null)
{
if (left == null)
left = ParseUnary();
if (IsBinaryToken())
{
TokenType token = Tokenizer.Token;
if (!BinaryOperationTokens.ContainsKey(token))
token = BinaryOperationAliases[Tokenizer.Value];
NextToken(true);
IExpressionNode right = ParseUnary();
left = ParseBinaryExpression(left, right, token, false);
}
if (Tokenizer.Token == TokenType.Question)
{
NextToken(true);
IExpressionNode expr1 = ParseExpression();
ValidateToken(TokenType.Colon);
NextToken(true);
IExpressionNode expr2 = ParseExpression();
left = new ConditionExpressionNode(left, expr1, expr2);
}
if (Tokenizer.Token == TokenType.DoubleQuestion)
{
NextToken(true);
IExpressionNode right = ParseExpression();
left = new BinaryExpressionNode(left, right, TokenType.DoubleQuestion);
}
return left;
}
