private AstNodeBase GetPropExpr1(AstNodeBase leftChild)
{
if (!_tokenizer.HasNext)
{
return(null);
}
var token = _tokenizer.NextToken();
if (token?.Operator?.Type == OperatorType.Reference)
{
var strtoken = _tokenizer.NextToken();
AstNodeBase rchild = new StringConstantAstNode {
Token = strtoken, DeductedType = typeof(string)
};
AstNodeBase node = new PropertyAstNode()
{
Token = token, RightChild = rchild,
};
var nodebase = GetPropExpr1(node);
return(nodebase ?? node);
}
_tokenizer.Failback(token);
return(null);
}
/// <summary>
/// ValExpr ::= DATE
/// | NUMBER
/// | BOOL
/// | PropExpr
/// | STRING
///
/// </summary>
/// <returns></returns>
private AstNodeBase GetValExpr()
{
if (!_tokenizer.HasNext)
{
return(null);
}
var node = GetPropExpr();
if (node != null)
{
return(node);
}
var token = _tokenizer.NextToken();
if (token.Type == TokenType.DateLiteral)
{
AstNodeBase tnode = new DateConstantAstNode()
{
Token = token
};
return(tnode);
}
if (token.Type == TokenType.NumberLiteral)
{
AstNodeBase tnode = new NumberConstantAstNode()
{
Token = token
};
return(tnode);
}
if (token.Type == TokenType.StringLiteral)
{
AstNodeBase tnode = new StringConstantAstNode()
{
Token = token
};
return(tnode);
}
_tokenizer.Failback(token);
return(null);
}
