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antlr
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wasn't chked out 

[git-p4: depot-paths = "//depot/code/antlr4/main/": change = 8868]
This commit is contained in:
parrt 2011-07-16 15:45:20 -08:00
parent 7a109d29d5
commit c3f5bbed37
1 changed files with 18 additions and 0 deletions
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18
runtime/Java/src/org/antlr/v4/runtime/tree/ElementList.java
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@ -35,9 +35,17 @@ import java.util.*;
public class ElementList<E> extends ArrayList<E> {
protected TreeAdaptor adaptor;
/** Once a node / subtree has been used in a stream, it must be dup'd
* from then on.
*/
protected HashSet<Integer> used = new HashSet<Integer>();
public class ElementListIterator implements Iterator<E> {
int cursor = 0;
/** If just 1 element, we still track cursor; next() will dup if
* cursor beyond 1 element.
*/
public boolean hasNext() {
int n = size();
return (n==1 && cursor<1) || (n>1 && cursor<n);
@ -72,6 +80,16 @@ public class ElementList<E> extends ArrayList<E> {
this.adaptor = adaptor;
}
@Override
public E get(int index) {
E o = super.get(index);
if ( used.contains(index) ) {
return (E)adaptor.dupTree( o );
}
used.add(index); // any subsequent ref must be dup'd
return o;
}
@Override
public Iterator<E> iterator() {
return new ElementListIterator();