Class BaseListCommonStream<E>

  extended by org.shapelogic.streams.BaseCommonStream<E>
      extended by org.shapelogic.streams.BaseListCommonStream<E>
All Implemented Interfaces:
java.lang.Iterable<E>, java.util.Iterator<E>, CalcValue<E>, ContextGettable, LazyCalc<E>, RecursiveContext, ListStream<E>, NumberedStream<E>, Stream<E>, StreamProperties
Direct Known Subclasses:
BaseListIndexedStream1, BaseListStream0, BaseListStream1, BaseListStream2, BaseListStreamList, IteratorStream, SingleListStream, WrappedListStream

public abstract class BaseListCommonStream<E>
extends BaseCommonStream<E>
implements ListStream<E>

Implementation of ListStream.
Close to
1: a lazy stream.
2: a UNIX pipe.

This is close to org.apache.commons.collections.list.LazyList, but that takes a factory to calculate next element, and that works badly here. How should a step work?
Normally call the hasNext, in order for this to work it would have to do the calculation.

So _current should be the last element that has been returned.

So when you call hasNext it will add that element to the list. When you call next it will bump the counter up one element if goes too high then do the calculation. At the end it will get to a point where the calculation fails. At that point last will be set to the current element. I will ignore synchronization to begin with.

Sami Badawi

Field Summary
protected  java.util.List<E> _list
Fields inherited from class org.shapelogic.streams.BaseCommonStream
_context, _current, _dirty, _last, _maxLast, _name, _nullLegalValue, _parentContext, _query, _value
Constructor Summary
Method Summary
protected  boolean calcAddNext()
          Try to calculate one more, independent of the _current.
 E get(int inputIndex)
          Get next element without advancing _current.
 int getCurrentSize()
 java.util.List<E> getList()
          Get underlying list.
 boolean hasNext()
 boolean hasNextBase()
abstract  E invokeIndex(int index)
          Calculate the value at an index.
 boolean isCached()
          If there is a list that contains all the results.
 boolean isRandomAccess()
          If you can calculate 1 element independent of other elements.
 java.util.Iterator<E> iterator()
 E next()
          Get next element and advance _current.
protected  void setLastFromInput()
 void setList(java.util.List<E> list)
          Get underlying list.
Methods inherited from class org.shapelogic.streams.BaseCommonStream
getContext, getInContext, getIndex, getLast, getMaxLast, getName, getParentContext, getValue, isDeterministic, isDirty, isNullLegalValue, remove, setMaxLast, setNullLegalValue, setup
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface org.shapelogic.streams.NumberedStream
getIndex, getLast, getMaxLast, setMaxLast
Methods inherited from interface org.shapelogic.calculation.LazyCalc
isDirty, setup
Methods inherited from interface org.shapelogic.calculation.CalcValue
Methods inherited from interface java.util.Iterator

Field Detail


protected java.util.List<E> _list
Constructor Detail


public BaseListCommonStream()
Method Detail


public abstract E invokeIndex(int index)
Calculate the value at an index.
So it gets the needed input value and call the appropriate invoke function.
Can this be used for a filter call?
The index does not make sense for a filter since you do not know where the input is coming from. So maybe just ignore it.
This is a little messy but less messy that what is there now.

Specified by:
invokeIndex in class BaseCommonStream<E>


public boolean hasNext()
Specified by:
hasNext in interface java.util.Iterator<E>


protected boolean calcAddNext()
Try to calculate one more, independent of the _current.

Specified by:
calcAddNext in class BaseCommonStream<E>


public boolean hasNextBase()


protected void setLastFromInput()
setLastFromInput in class BaseCommonStream<E>


public E next()
Get next element and advance _current.

Specified by:
next in interface java.util.Iterator<E>


public E get(int inputIndex)
Get next element without advancing _current.

Specified by:
get in interface NumberedStream<E>


public boolean isRandomAccess()
Description copied from interface: StreamProperties
If you can calculate 1 element independent of other elements.

Specified by:
isRandomAccess in interface StreamProperties


public boolean isCached()
If there is a list that contains all the results. I would think that this should always happen for a ListStream, but it could happen for other streams as well.

Specified by:
isCached in interface StreamProperties


public int getCurrentSize()


public java.util.List<E> getList()
Description copied from interface: ListStream
Get underlying list.

Specified by:
getList in interface ListStream<E>


public void setList(java.util.List<E> list)
Description copied from interface: ListStream
Get underlying list.

Specified by:
setList in interface ListStream<E>


public java.util.Iterator<E> iterator()
Specified by:
iterator in interface java.lang.Iterable<E>

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