private async Task <SqlObject> IterateReference(MethodContext context, ObjectName refName, IGroupResolver groupResolver)
{
SqlObject result = null;
for (long i = 0; i < groupResolver.Size; i++)
{
var rowValue = await groupResolver.ResolveReferenceAsync(refName, i);
var current = rowValue;
using (var accumulate = new IterateContext(context, i, result, current)) {
await IterateAsync(accumulate);
if (accumulate.Result == null)
{
throw new MethodAccessException("No result value was provided by the iteration");
}
result = accumulate.Result;
if (!accumulate.Iterate)
{
break;
}
}
}
return(result);
}
private async Task <SqlObject> IterateValues(MethodContext context, SqlExpression input, IGroupResolver groupResolver)
{
SqlObject result = null;
for (long i = 0; i < groupResolver.Size; i++)
{
SqlObject value;
var resolver = groupResolver.GetResolver(i);
using (var reduce = context.Create("reduce", scope => scope.AddReferenceResolver(resolver))) {
var reduced = await input.ReduceAsync(reduce);
if (reduced.ExpressionType != SqlExpressionType.Constant)
{
throw new InvalidOperationException();
}
value = ((SqlConstantExpression)reduced).Value;
}
using (var accumulate = new IterateContext(context, i, result, value)) {
await IterateAsync(accumulate);
if (accumulate.Result == null)
{
throw new MethodAccessException("No result value was provided by the iteration");
}
result = accumulate.Result;
if (!accumulate.Iterate)
{
break;
}
}
}
return(result);
}
protected override Task IterateAsync(IterateContext context)
{
return(iterate(context));
}
protected abstract Task IterateAsync(IterateContext context);