public override IEnumerable <OutputRecord> Execute(ParseEngine engine)
{
var current = Enclosure.Execute(engine);
if (engine.IsFailure(current))
{
return(current);
}
Func <IEnumerable <OutputRecord> > predicate = () =>
{
var mark = engine.Mark();
var result = Enclosure.Execute(engine);
engine.Reset(mark);
return(result);
};
engine.AddInterceptor(predicate);
try
{
var operandResult = Operand.Execute(engine);
if (engine.IsFailure(operandResult))
{
return(operandResult);
}
current = current.Concat(operandResult);
}
finally
{
engine.RemoveInterceptor(predicate);
}
var closeResult = Enclosure.Execute(engine);
if (engine.IsFailure(closeResult))
{
return(closeResult);
}
return(current.Concat(closeResult));
}
