public void ParseString()
{
Parser parser = new Parser("\"foo\".");
IExpression expression = parser.ParseExpression();
Assert.IsNotNull(expression);
Assert.IsInstanceOfType(expression, typeof(ConstantExpression));
ConstantExpression consexpression = (ConstantExpression)expression;
Assert.IsNotNull(consexpression.Value);
Assert.AreEqual("foo", consexpression.Value);
Assert.IsNull(parser.ParseExpression());
}