/// <summary>
/// Scans ahead for a possibly Identifier/Alias and returns the value
/// if it finds one. if it does find one, it will move the Window accordingly
/// </summary>
/// <param name="xoToken"></param>
/// <param name="xoList"></param>
/// <returns></returns>
public static String ScanAheadForAlias(SyntaxList xoList)
{
String sAlias = String.Empty;
// SCAN AHEAD - To grab an alias if there is one
if (xoList.HasTokensLeftToProcess())
{
ISyntax oNextNode = xoList.Peek();
// Explicit
if (oNextNode.ExpectedType == SyntaxKind.AsKeyword)
{
// And the next node after that is an identifier
if (xoList.Peek(1).ExpectedType == SyntaxKind.IdentifierToken)
{
// Alias found
sAlias = xoList.Peek(1).RawSQLText;
xoList.Pop(2);
}
}
// Implicit
else if (oNextNode.ExpectedType == SyntaxKind.IdentifierToken)
{
// Alias found
sAlias = oNextNode.RawSQLText;
xoList.Pop();
}
}
// Return the newly created table node
return(sAlias);
}
/// <summary>
/// Core function for this object. It will attempt to build a source
/// program tree from the stored list of tokens
/// </summary>
/// <returns></returns>
public SyntaxNode ParseTree()
{
// Initialise the Query
QuerySyntaxNode oQuery = new QuerySyntaxNode();
// WHILE has tokens to process
// Anytime we get here, create a new statement?
while (TokenList.HasTokensLeftToProcess())
{
// Initialise a new statement every time we get here
StatementSyntaxNode oStatement = new StatementSyntaxNode();
// Pull off the first node
SyntaxNode CurrentNode = SyntaxNodeFactory.ContextSensitiveConvertTokenToNode(new ParsingContext(oQuery, TokenList));
// If we consumed anything
if (CurrentNode.TryConsumeFromContext(new ParsingContext(CurrentNode, TokenList)))
{
}
// Append to the statement anyways
oStatement.Add(CurrentNode);
oQuery.Add(oStatement);
}
// Return the Query
return(oQuery);
}
