public void CreateBinaryExpression()
{
IExpression leftExpression = new ConstantExpression(1);
IExpression rightExpression = new ConstantExpression(2);
BinaryExpression expression = new ArithmeticBinaryExpression(ArithmeticOperator.Add, leftExpression, rightExpression);
Assert.IsTrue(expression.LeftExpression == leftExpression);
Assert.IsTrue(expression.RightExpression == rightExpression);
}
private static object EvaluateArithmeticBinaryOperator(ArithmeticOperator operation, object left, object right)
{
IExpression expression = new ArithmeticBinaryExpression(operation, new ConstantExpression(left), new ConstantExpression(right));
return expression.Evaluate(null);
}
private IExpression ParseBinaryExpressionSecondLevel()
{
IExpression expression = this.ParseUnaryExpression();
if (expression == null)
return null;
while (this.TryParse(TokenType.Operator, "*", "/", @"\", "%"))
{
Token oper = this.lexer.NextToken();
IExpression right = this.ParseUnaryExpression();
ArithmeticOperator op;
if (oper.Value == "*")
op = ArithmeticOperator.Multiply;
else if (oper.Value == "/")
op = ArithmeticOperator.Divide;
else if (oper.Value == "\\")
op = ArithmeticOperator.IntegerDivide;
else if (oper.Value == "%")
op = ArithmeticOperator.Modulo;
else
throw new ParserException(string.Format("Invalid operator '{0}'", oper.Value));
expression = new ArithmeticBinaryExpression(op, expression, right);
}
return expression;
}
private IExpression ParseBinaryExpressionFirstLevel()
{
IExpression expression = this.ParseBinaryExpressionSecondLevel();
if (expression == null)
return null;
while (this.TryParse(TokenType.Operator, "+", "-"))
{
Token oper = this.lexer.NextToken();
IExpression right = this.ParseBinaryExpressionSecondLevel();
ArithmeticOperator op = oper.Value == "+" ? ArithmeticOperator.Add : ArithmeticOperator.Subtract;
expression = new ArithmeticBinaryExpression(op, expression, right);
}
return expression;
}
public void ExecuteForCommand()
{
ICommand setX = new SetVariableCommand("x", new ConstantExpression(0));
ICommand setY = new SetVariableCommand("y", new ConstantExpression(0));
List<ICommand> commands = new List<ICommand>();
commands.Add(setX);
commands.Add(setY);
ICommand initialCommand = new CompositeCommand(commands);
IExpression condition = new CompareExpression(ComparisonOperator.Less, new VariableExpression("x"), new ConstantExpression(6));
IExpression addXtoY = new ArithmeticBinaryExpression(ArithmeticOperator.Add, new VariableExpression("y"), new VariableExpression("x"));
ICommand addToY = new SetVariableCommand("y", addXtoY);
ICommand endCommand = new SetVariableCommand("x", new ArithmeticBinaryExpression(ArithmeticOperator.Add, new VariableExpression("x"), new ConstantExpression(1)));
ForCommand forcmd = new ForCommand(initialCommand, condition, endCommand, addToY);
BindingEnvironment environment = new BindingEnvironment();
environment.SetValue("y", null);
forcmd.Execute(environment);
Assert.AreEqual(15, environment.GetValue("y"));
}
public void ExecuteWhileCommand()
{
IExpression incrementX = new ArithmeticBinaryExpression(ArithmeticOperator.Add, new ConstantExpression(1), new VariableExpression("x"));
IExpression decrementY = new ArithmeticBinaryExpression(ArithmeticOperator.Subtract, new VariableExpression("y"), new ConstantExpression(1));
ICommand setX = new SetVariableCommand("x", incrementX);
ICommand setY = new SetVariableCommand("y", decrementY);
List<ICommand> commands = new List<ICommand>();
commands.Add(setX);
commands.Add(setY);
ICommand command = new CompositeCommand(commands);
IExpression yexpr = new VariableExpression("y");
WhileCommand whilecmd = new WhileCommand(yexpr, command);
BindingEnvironment environment = new BindingEnvironment();
environment.SetValue("x", 0);
environment.SetValue("y", 5);
whilecmd.Execute(environment);
Assert.AreEqual(0, environment.GetValue("y"));
Assert.AreEqual(5, environment.GetValue("x"));
}
public void ExecuteForEachCommand()
{
IExpression addToX = new ArithmeticBinaryExpression(ArithmeticOperator.Add, new VariableExpression("y"), new VariableExpression("x"));
ICommand setX = new SetVariableCommand("x", addToX);
IExpression values = new ConstantExpression(new int[] { 1, 2, 3 });
ForEachCommand foreachcmd = new ForEachCommand("y", values, setX);
BindingEnvironment environment = new BindingEnvironment();
environment.SetValue("x", 0);
foreachcmd.Execute(environment);
Assert.AreEqual(6, environment.GetValue("x"));
}