/// <summary>
/// Event handler for the calculate button.
/// Parses and evaluates the input expression.
/// If the expression was valid, the result are shown in the main list view.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnCalculateExpression_Click(object sender, EventArgs e)
{
string expression = ReadExpression();
lstResultList.Items.Add(String.Format(">> {0}", expression));
//Calculate expression and add result to list
RowEvaluator evaluator = new RowEvaluator(expression);
//Try to parse and evaluate the expression.
//Any errors are printed to the main list view.
if (ParseExpression(evaluator) && EvaluateExpression(evaluator))
{
try
{
PrintValue(evaluator.InterpretedExpression);
}
catch (Exception ex)
{
lstResultList.Items.Add(String.Format(" error: {0}", ex.Message));
}
}
AddExpressionToHistory(expression);
lstResultList.Items.Add(String.Empty);
UpdateGUI();
}
/// <summary>
/// Tries to evaluate the input expression contained in the given evaluator.
/// </summary>
/// <param name="evaluator">The row evaluator with the given expression.</param>
/// <returns>True if the evaluation was successfull.</returns>
private bool EvaluateExpression(RowEvaluator evaluator)
{
try
{
evaluator.InterpretExpression();
return(true);
}
catch (Exception ex)
{
lstResultList.Items.Add(String.Format(" error: {0}", ex.Message));
return(false);
}
}
internal void Evaluate(out List <ExpressionItem> list)
{
Scanner scanner = new Scanner(scriptFileContents, Environment.NewLine);
RowEvaluator rowEvaluator;
list = new List <ExpressionItem>();
while (scanner.HasNext())
{
rowEvaluator = new RowEvaluator(scanner.Next());
rowEvaluator.ParseExpression();
rowEvaluator.InterpretExpression();
list.Add(rowEvaluator.InterpretedExpression);
}
}
