/// <summary>
/// Creates new instance of the map entry defined by this node.
/// </summary>
/// <param name="context">Context to evaluate expressions against.</param>
/// <param name="evalContext">Current expression evaluation context.</param>
/// <returns>Node's value.</returns>
protected override object Get(object context, EvaluationContext evalContext)
{
BaseNode firstChild = (BaseNode)this.getFirstChild();
object key = GetValue(firstChild, context, evalContext);
object value = GetValue((BaseNode)firstChild.getNextSibling(), context, evalContext);
return(new DictionaryEntry(key, value));
}
/// <summary>
/// Returns a <see cref="IList"/> containing results of evaluation
/// of selection expression against each node in the context.
/// </summary>
/// <param name="context">Context to evaluate expressions against.</param>
/// <param name="evalContext">Current expression evaluation context.</param>
/// <returns>Node's value.</returns>
protected override object Get(object context, EvaluationContext evalContext)
{
IEnumerable enumerable = context as IEnumerable;
if (enumerable == null)
{
throw new ArgumentException(
"Selection can only be used on an instance of the type that implements IEnumerable.");
}
BaseNode expression = (BaseNode)this.getFirstChild();
BaseNode minIndexExpression = (BaseNode)expression.getNextSibling();
BaseNode maxIndexExpression = (minIndexExpression == null) ? null : (BaseNode)minIndexExpression.getNextSibling();
int minIndex = (int)((minIndexExpression == null)
? Int32.MinValue
: GetValue(minIndexExpression, context, evalContext));
int maxIndex = (int)((maxIndexExpression == null)
? Int32.MaxValue
: GetValue(maxIndexExpression, context, evalContext));
IList selectionList = new ArrayList();
using (evalContext.SwitchThisContext())
{
int found = 0;
foreach (object o in enumerable)
{
evalContext.ThisContext = o;
bool isMatch = (bool)GetValue(expression, o, evalContext);
if (isMatch)
{
if (minIndex <= found && found <= maxIndex)
{
selectionList.Add(o);
}
found++;
if (found > maxIndex)
{
break; // don't look any further
}
}
}
}
return(selectionList);
}