/// <summary>
/// Visit VarExpression
/// </summary>
/// <param name="expression">VarExpression to check</param>
public override void Visit(VarExpression expression)
{
//Check if expression is assigned to existing variable
if (!SymbolTable.ContainsVariable(expression.GetVariableIdentifier()))
{ //Add undefined variable exception
ExceptionList.Add(new UndefinedVariable(expression.GetVariableIdentifier()));
}
}
public void ParseVarExpressionTest()
{
//Create parser and parse tokens
ExpressionParser expressionParser = new ExpressionParser(Init("home"));
VarExpression expression = expressionParser.ParseVarExpression();
//Test variable identifier
Assert.AreEqual("home", expression.GetVariableIdentifier());
}
public void ParseCatExpressionTest()
{
//Create parser and parse tokens
ExpressionParser expressionParser = new ExpressionParser(Init("expression+'symbol"));
Expression expression = expressionParser.ParseExpression();
//Check type of expression
Assert.AreEqual(typeof(CatExpression), expression.GetType());
CatExpression parsedCatExpression = (CatExpression)expression;
//Check expressions in catexpression
Assert.AreEqual(typeof(VarExpression), parsedCatExpression.GetLeftExpression().GetType());
Assert.AreEqual(typeof(SymExpression), parsedCatExpression.GetRightExpression().GetType());
VarExpression left = (VarExpression)parsedCatExpression.GetLeftExpression();
SymExpression right = (SymExpression)parsedCatExpression.GetRightExpression();
Assert.AreEqual("expression", left.GetVariableIdentifier());
Assert.AreEqual("symbol", right.GetSym());
}
