public override Value Next()
{
using var popper = new RegionPopper(region, "if-generator");
popper.Push();
switch (ifStage)
{
case IfStage.Condition:
if (condition.IsTrue)
{
ifStage = IfStage.Result;
return(resultGenerator.Next());
}
if (_elseIf.If(out var elseIf))
{
ifStage = IfStage.ElseIf;
return(elseIf.Next());
}
if (_elseBlockGenerator.If(out var elseBlockGenerator))
{
ifStage = IfStage.Else;
return(elseBlockGenerator.Next());
}
return(NilValue);
case IfStage.Result:
return(resultGenerator.Next());
case IfStage.ElseIf:
return(_elseIf.If(out elseIf) ? elseIf.Next() : NilValue);
case IfStage.Else:
return(_elseBlockGenerator.If(out elseBlockGenerator) ? elseBlockGenerator.Next() : NilValue);
default:
return(IgnoreValue);
}
}
public override Value Next()
{
if (current.If(out var value))
{
if (index++ < MAX_LOOP && compare(value, stop) < 0)
{
var next = successor(value);
var result = value;
current = next.Some();
return(result);
}
}
if (current.If(out value))
{
var result = value;
current = none <Object>();
return(result);
}
return(NilValue);
}
public override Value Next()
{
if (currentIterator.If(out var iterator))
{
var value = iterator.Next();
if (value.IsNil)
{
currentIterator = none <NSIterator>();
}
else
{
return(value);
}
}
while (iterators.Count > 0)
{
currentIterator = iterators.Dequeue();
if (currentIterator.If(out iterator))
{
iterator.Reset();
var value = iterator.Next();
if (!value.IsNil)
{
return(value);
}
}
else
{
return(NilValue);
}
}
return(NilValue);
}