ValueIterator (Teiid 15.0.0 API)

All Known Implementing Classes:

CollectionValueIterator
```
public interface ValueIterator
```
Interface for interating through Expressions or values. It may return instances of Expression (which then have to be evaluated) or it may return some Object constant value - this should be checked for after calling next
This interface is meant to abstract the details of how the values are stored and retrieved, if they are even stored in memory or not, etc. etc. An implementation instance may or may not be resettable and therefore reusable - see reset.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`boolean`	`hasNext()`	Returns `true` if the iteration has more values.
`Object`	`next()`	Returns the next Expression or Object value in the interation.
`void`	`reset()`	Optional reset method - allows a single instance of a ValueIterator implementation to be resettable, such that the next call to `next` returns the first element in the iteration (if any).

- Method Detail
  - hasNext
```
boolean hasNext()
         throws TeiidComponentException
```
    Returns true if the iteration has more values. (In other words, returns true if next would return a value rather than throwing an exception.)
    
    Returns:
    
    true if this ValueIterator has more values.
    
    Throws:
    
    TeiidComponentException - indicating a non business- related Exception such as a service or bean being unavailable, or a communication failure.
  - next
```
Object next()
     throws TeiidComponentException
```
    Returns the next Expression or Object value in the interation.
    
    Returns:
    
    the next Expression or Object value in the iteration.
    
    Throws:
    
    TeiidComponentException - indicating a non business- related Exception such as a service or bean being unavailable, or a communication failure.
  - reset
```
void reset()
```
    Optional reset method - allows a single instance of a ValueIterator implementation to be resettable, such that the next call to next returns the first element in the iteration (if any). This method should be able to be called at any point during the lifecycle of a ValueIterator instance.
    
    Throws:
    
    UnsupportedOperationException - if this method is not implemented