private ASTNode ParseInternal(string input)
{
tokenStream = new TokenStream(ExpressionTokenizer.Tokenize(input, StructList <ExpressionToken> .Get()));
expressionStack = expressionStack ?? StackPool <ASTNode> .Get();
operatorStack = operatorStack ?? StackPool <OperatorNode> .Get();
if (tokenStream.Current == ExpressionTokenType.ExpressionOpen)
{
tokenStream.Advance();
}
if (!tokenStream.HasMoreTokens)
{
throw new ParseException("Failed trying to parse empty expression");
}
if (tokenStream.Last == ExpressionTokenType.ExpressionClose)
{
tokenStream.Chop();
}
ASTNode retn = ParseLoop();
Release();
return(retn);
}