private static string AsName(IExpression expression)
{
if (expression is VariableExpression)
{
return(((VariableExpression)expression).Name);
}
if (expression is DotExpression)
{
DotExpression dot = (DotExpression)expression;
return(AsName(dot.Expression) + "." + dot.Name);
}
return(null);
}
public void EvaluateDotExpressionOnString()
{
IExpression expression = new DotExpression(new ConstantExpression("foo"), "Length");
Assert.AreEqual(3, expression.Evaluate(null));
}
public void EvaluateDotExpressionOnInteger()
{
IExpression expression = new DotExpression(new ConstantExpression(1), "ToString", new List<IExpression>());
Assert.AreEqual("1", expression.Evaluate(null));
}
public void EvaluateDotExpressionAsTypeInvocation()
{
DotExpression dot = new DotExpression(new DotExpression(new DotExpression(new VariableExpression("System"), "IO"), "File"), "Exists", new IExpression[] { new ConstantExpression("unknown.txt") });
Assert.IsFalse((bool) dot.Evaluate(new Context()));
}
private IExpression ParseDotExpression()
{
IExpression expression = this.ParseSimpleExpression();
if (expression == null)
return null;
while (this.TryParseToken(".", TokenType.Separator))
{
string name = this.ParseName();
if (this.TryParseToken("(", TokenType.Separator))
{
expression = new DotExpression(expression, name, this.ParseExpressionList(")"));
}
else
expression = new DotExpression(expression, name);
}
return expression;
}