public virtual void Visit(NullExpression expression)
{
}
private Expression ParseExpression()
{
Expression value;
if (_tokenStream.IsEmpty())
{
value = new NullExpression();
}
else
{
Token tok = PeekToken();
if (tok == ReferenceStartToken || tok == OldReferenceStartToken)
value = ParseReference();
else if (tok.type == TokenType.Number
|| (IsIdentifier(tok) && !IsKeyword(tok)))
{
value = ParsePrimitive();
}
else if (IsQuotedString(tok))
{
value = ParseString();
}
else if (tok == LSquareToken)
{
value = ParseCollection();
}
else if (tok == LBraceToken)
{
value = ParseObject();
}
else if (tok == LParenToken)
{
value = ParseCast();
}
else if (tok == NewToken)
{
value = ParseConstructedObject();
}
else
{
throw new ParseException(string.Format("Unexpected token: {0} at Line: {1}, Position: {2}", tok, tok.linenumber, tok.position));
}
}
return value;
}
