public void EvaluateUndefinedVariable()
{
Context context = new Context();
VariableExpression expr = new VariableExpression("Foo");
Assert.IsNull(expr.Evaluate(context));
}
public void EvaluateDefinedVariable()
{
Context context = new Context();
context.SetValue("One", 1);
VariableExpression expr = new VariableExpression("One");
Assert.AreEqual(1, expr.Evaluate(context));
}
public void EvaluateDefinedMethod()
{
Context context = new Context();
IList<ICommand> commandlist = new List<ICommand>();
commandlist.Add(new SetVariableCommand("a", new ConstantExpression(1)));
commandlist.Add(new SetVariableCommand("b", new ConstantExpression(2)));
commandlist.Add(new ExpressionCommand(new VariableExpression("b")));
CompositeCommand commands = new CompositeCommand(commandlist);
DefinedMethod method = new DefinedMethod(null, commands);
context.SetValue("foo", method);
VariableExpression expr = new VariableExpression("foo");
Assert.AreEqual(2, expr.Evaluate(context));
}
private IExpression ParseSimpleExpression()
{
Token token = this.NextToken();
if (token == null)
return null;
switch (token.Type)
{
case TokenType.Integer:
return new ConstantExpression(int.Parse(token.Value, CultureInfo.InvariantCulture));
case TokenType.Name:
string name = token.Value;
token = this.NextToken();
if (IsReservedWord(token))
{
this.PushToken(token);
return new VariableExpression(name);
}
if (token != null && token.Type != TokenType.Separator && token.Type != TokenType.Operator && token.Type != TokenType.EndOfLine)
{
this.PushToken(token);
return new CallExpression(new NameExpression(name), new IExpression[] { this.ParseExpression() });
}
if (token != null && token.Type == TokenType.Separator && token.Type == TokenType.Separator && token.Value == "(")
{
this.PushToken(token);
return new CallExpression(new NameExpression(name), this.ParseArguments());
}
IExpression expr = new VariableExpression(name);
if (token != null)
this.PushToken(token);
return expr;
case TokenType.String:
return new ConstantExpression(token.Value);
}
throw new ParserException(string.Format("Unexpected '{0}'", token.Value));
}
