/// <summary>
/// Returns a visitor with the results of a single parsing pass
/// </summary>
/// <param name="textToParse">Z80 assembly code to parse</param>
/// <param name="expectedErrors">Number of errors expected</param>
/// <returns>
/// Visitor with the syntax tree
/// </returns>
protected virtual ExpressionNode ParseExpr(string textToParse, int expectedErrors = 0)
{
var inputStream = new AntlrInputStream(textToParse);
var lexer = new Z80AsmLexer(inputStream);
var tokenStream = new CommonTokenStream(lexer);
var parser = new Z80AsmParser(tokenStream);
var context = parser.expr();
var visitor = new Z80AsmVisitor();
parser.SyntaxErrors.Count.ShouldBe(expectedErrors);
return((ExpressionNode)visitor.VisitExpr(context));
}
