Top Description Inners Fields Constructors Methods
org.antlr.runtime.tree

public Class BufferedTreeNodeStream

extends Object
implements TreeNodeStream
Class Inheritance
All Implemented Interfaces
org.antlr.runtime.tree.TreeNodeStream, org.antlr.runtime.IntStream
Imports
org.antlr.runtime.Token, .TokenStream, org.antlr.runtime.misc.IntArray, java.util.*

A buffered stream of tree nodes. Nodes can be from a tree of ANY kind. This node stream sucks all nodes out of the tree specified in the constructor during construction and makes pointers into the tree using an array of Object pointers. The stream necessarily includes pointers to DOWN and UP and EOF nodes. This stream knows how to mark/release for backtracking. This stream is most suitable for tree interpreters that need to jump around a lot or for tree parsers requiring speed (at cost of memory). There is some duplicated functionality here with UnBufferedTreeNodeStream but just in bookkeeping, not tree walking etc... TARGET DEVELOPERS: This is the old CommonTreeNodeStream that buffered up entire node stream. No need to implement really as new CommonTreeNodeStream is much better and covers what we need.
See Also
CommonTreeNodeStream

Nested and Inner Type Summary

Modifier and TypeClass and Description
protected class

Field Summary

Modifier and TypeField and Description
pack-priv TreeAdaptor
adaptor

What tree adaptor was used to build these trees

protected IntArray
calls

Stack of indexes used for push/pop calls

public static final int
protected Object
protected Object
public static final int
protected int
lastMarker

Track the last mark() call result value for use in rewind().

protected List<Object>
nodes

The complete mapping from stream index to tree node.

protected int
p

The index into the nodes list of the current node (next node to consume).

protected Object
root

Pull nodes from which tree?

protected TokenStream
tokens

IF this tree (root) was created from a token stream, track it.

protected boolean
uniqueNavigationNodes

Reuse same DOWN, UP navigation nodes unless this is true

protected Object

Constructor Summary

AccessConstructor and Description
public
public
public
BufferedTreeNodeStream(TreeAdaptor adaptor, Object tree, int initialBufferSize)

Method Summary

Modifier and TypeMethod and Description
protected void
addNavigationNode(final int ttype)

As we flatten the tree, we use UP, DOWN nodes to represent the tree structure.

public void
protected void
fillBuffer()

Walk tree with depth-first-search and fill nodes buffer.

public void
public Object
get(int i)

Implements org.antlr.runtime.tree.TreeNodeStream.get.

Get a tree node at an absolute index i; 0..n-1.
public Object
protected int
getNodeIndex(Object node)

What is the stream index for node?

public String
getSourceName()

Implements org.antlr.runtime.IntStream.getSourceName.

Where are you getting symbols from?
public TokenStream
getTokenStream()

Implements org.antlr.runtime.tree.TreeNodeStream.getTokenStream.

If the tree associated with this stream was created from a TokenStream, you can specify it here.
public TreeAdaptor
getTreeAdaptor()

Implements org.antlr.runtime.tree.TreeNodeStream.getTreeAdaptor.

What adaptor can tell me how to interpret/navigate nodes and trees.
public Object
getTreeSource()

Implements org.antlr.runtime.tree.TreeNodeStream.getTreeSource.

Where is this stream pulling nodes from?
public boolean
public int
index()

Implements org.antlr.runtime.IntStream.index.

Return the current input symbol index 0..n where n indicates the last symbol has been read.
public Iterator<Object>
public int
LA(int i)

Implements org.antlr.runtime.IntStream.LA.

Get int at current input pointer + i ahead where i=1 is next int.
protected Object
LB(int k)

Look backwards k nodes

public Object
LT(int k)

Implements org.antlr.runtime.tree.TreeNodeStream.LT.

Get tree node at current input pointer + k ahead where k==1 is next node.
public int
mark()

Implements org.antlr.runtime.IntStream.mark.

Tell the stream to start buffering if it hasn't already.
public int
pop()

Seek back to previous index saved during last push() call.

public void
push(int index)

Make stream jump to a new location, saving old location.

public void
release(int marker)

Implements org.antlr.runtime.IntStream.release.

You may want to commit to a backtrack but don't want to force the stream to keep bookkeeping objects around for a marker that is no longer necessary.
public void
replaceChildren(Object parent, int startChildIndex, int stopChildIndex, Object t)

Implements org.antlr.runtime.tree.TreeNodeStream.replaceChildren.

Replace children of parent from index startChildIndex to stopChildIndex with t, which might be a list.
public void
reset()

Implements org.antlr.runtime.tree.TreeNodeStream.reset.

Reset the tree node stream in such a way that it acts like a freshly constructed stream.
public void
rewind(int marker)

Implements org.antlr.runtime.IntStream.rewind.

Reset the stream so that next call to index would return marker.
public void
rewind()

Implements org.antlr.runtime.IntStream.rewind.

Rewind to the input position of the last marker.
public void
seek(int index)

Implements org.antlr.runtime.IntStream.seek.

Set the input cursor to the position indicated by index.
public void
public void
public void
setUniqueNavigationNodes(boolean uniqueNavigationNodes)

Implements org.antlr.runtime.tree.TreeNodeStream.setUniqueNavigationNodes.

As we flatten the tree, we use Token#UP, Token#DOWN nodes to represent the tree structure.
public int
size()

Implements org.antlr.runtime.IntStream.size.

Only makes sense for streams that buffer everything up probably, but might be useful to display the entire stream or for testing.
public String
toString(Object start, Object stop)

Implements org.antlr.runtime.tree.TreeNodeStream.toString.

Return the text of all nodes from start to stop, inclusive.
public String
toTokenString(int start, int stop)

Debugging

public String
toTokenTypeString()

Used for testing, just return the token type stream

Inherited from java.lang.Object:
cloneequalsfinalizegetClasshashCodenotifynotifyAlltoStringwaitwaitwait

Field Detail

adaptorback to summary
pack-priv TreeAdaptor adaptor

What tree adaptor was used to build these trees

callsback to summary
protected IntArray calls

Stack of indexes used for push/pop calls

DEFAULT_INITIAL_BUFFER_SIZEback to summary
public static final int DEFAULT_INITIAL_BUFFER_SIZE
downback to summary
protected Object down
eofback to summary
protected Object eof
INITIAL_CALL_STACK_SIZEback to summary
public static final int INITIAL_CALL_STACK_SIZE
lastMarkerback to summary
protected int lastMarker

Track the last mark() call result value for use in rewind().

nodesback to summary
protected List<Object> nodes

The complete mapping from stream index to tree node. This buffer includes pointers to DOWN, UP, and EOF nodes. It is built upon ctor invocation. The elements are type Object as we don't what the trees look like. Load upon first need of the buffer so we can set token types of interest for reverseIndexing. Slows us down a wee bit to do all of the if p==-1 testing everywhere though.

pback to summary
protected int p

The index into the nodes list of the current node (next node to consume). If -1, nodes array not filled yet.

rootback to summary
protected Object root

Pull nodes from which tree?

tokensback to summary
protected TokenStream tokens

IF this tree (root) was created from a token stream, track it.

uniqueNavigationNodesback to summary
protected boolean uniqueNavigationNodes

Reuse same DOWN, UP navigation nodes unless this is true

upback to summary
protected Object up

Constructor Detail

BufferedTreeNodeStreamback to summary
public BufferedTreeNodeStream(Object tree)
BufferedTreeNodeStreamback to summary
public BufferedTreeNodeStream(TreeAdaptor adaptor, Object tree)
BufferedTreeNodeStreamback to summary
public BufferedTreeNodeStream(TreeAdaptor adaptor, Object tree, int initialBufferSize)

Method Detail

addNavigationNodeback to summary
protected void addNavigationNode(final int ttype)

As we flatten the tree, we use UP, DOWN nodes to represent the tree structure. When debugging we need unique nodes so instantiate new ones when uniqueNavigationNodes is true.

consumeback to summary
public void consume()

Implements org.antlr.runtime.IntStream.consume.

Annotations
@Override
fillBufferback to summary
protected void fillBuffer()

Walk tree with depth-first-search and fill nodes buffer. Don't do DOWN, UP nodes if its a list (t is isNil).

fillBufferback to summary
public void fillBuffer(Object t)
getback to summary
public Object get(int i)

Implements org.antlr.runtime.tree.TreeNodeStream.get.

Doc from org.antlr.runtime.tree.TreeNodeStream.get.

Get a tree node at an absolute index i; 0..n-1. If you don't want to buffer up nodes, then this method makes no sense for you.

Annotations
@Override
getCurrentSymbolback to summary
public Object getCurrentSymbol()
getNodeIndexback to summary
protected int getNodeIndex(Object node)

What is the stream index for node? 0..n-1 Return -1 if node not found.

getSourceNameback to summary
public String getSourceName()

Implements org.antlr.runtime.IntStream.getSourceName.

Doc from org.antlr.runtime.IntStream.getSourceName.

Where are you getting symbols from? Normally, implementations will pass the buck all the way to the lexer who can ask its input stream for the file name or whatever.

Annotations
@Override
getTokenStreamback to summary
public TokenStream getTokenStream()

Implements org.antlr.runtime.tree.TreeNodeStream.getTokenStream.

Doc from org.antlr.runtime.tree.TreeNodeStream.getTokenStream.

If the tree associated with this stream was created from a TokenStream, you can specify it here. Used to do rule $text attribute in tree parser. Optional unless you use tree parser rule $text attribute or output=template and rewrite=true options.

Annotations
@Override
getTreeAdaptorback to summary
public TreeAdaptor getTreeAdaptor()

Implements org.antlr.runtime.tree.TreeNodeStream.getTreeAdaptor.

Doc from org.antlr.runtime.tree.TreeNodeStream.getTreeAdaptor.

What adaptor can tell me how to interpret/navigate nodes and trees. E.g., get text of a node.

Annotations
@Override
getTreeSourceback to summary
public Object getTreeSource()

Implements org.antlr.runtime.tree.TreeNodeStream.getTreeSource.

Doc from org.antlr.runtime.tree.TreeNodeStream.getTreeSource.

Where is this stream pulling nodes from? This is not the name, but the object that provides node objects.

Annotations
@Override
hasUniqueNavigationNodesback to summary
public boolean hasUniqueNavigationNodes()
indexback to summary
public int index()

Implements org.antlr.runtime.IntStream.index.

Doc from org.antlr.runtime.IntStream.index.

Return the current input symbol index 0..n where n indicates the last symbol has been read. The index is the symbol about to be read not the most recently read symbol.

Annotations
@Override
iteratorback to summary
public Iterator<Object> iterator()
LAback to summary
public int LA(int i)

Implements org.antlr.runtime.IntStream.LA.

Doc from org.antlr.runtime.IntStream.LA.

Get int at current input pointer + i ahead where i=1 is next int. Negative indexes are allowed. LA(-1) is previous token (token just matched). LA(-i) where i is before first token should yield -1, invalid char / EOF.

Annotations
@Override
LBback to summary
protected Object LB(int k)

Look backwards k nodes

LTback to summary
public Object LT(int k)

Implements org.antlr.runtime.tree.TreeNodeStream.LT.

Doc from org.antlr.runtime.tree.TreeNodeStream.LT.

Get tree node at current input pointer + k ahead where k==1 is next node. k<0 indicates nodes in the past. So LT(-1) is previous node, but implementations are not required to provide results for k < -1. LT(0) is undefined. For k<=n, return null. Return null for LT(0) and any index that results in an absolute address that is negative.

This is analogous to TokenStream#LT, but this returns a tree node instead of a Token. Makes code generation identical for both parser and tree grammars.

Annotations
@Override
markback to summary
public int mark()

Implements org.antlr.runtime.IntStream.mark.

Doc from org.antlr.runtime.IntStream.mark.

Tell the stream to start buffering if it hasn't already. Return current input position, index(), or some other marker so that when passed to rewind() you get back to the same spot. rewind(mark()) should not affect the input cursor. The Lexer track line/col info as well as input index so its markers are not pure input indexes. Same for tree node streams.

Annotations
@Override
popback to summary
public int pop()

Seek back to previous index saved during last push() call. Return top of stack (return index).

pushback to summary
public void push(int index)

Make stream jump to a new location, saving old location. Switch back with pop().

releaseback to summary
public void release(int marker)

Implements org.antlr.runtime.IntStream.release.

Doc from org.antlr.runtime.IntStream.release.

You may want to commit to a backtrack but don't want to force the stream to keep bookkeeping objects around for a marker that is no longer necessary. This will have the same behavior as rewind() except it releases resources without the backward seek. This must throw away resources for all markers back to the marker argument. So if you're nested 5 levels of mark(), and then release(2) you have to release resources for depths 2..5.

Annotations
@Override
replaceChildrenback to summary
public void replaceChildren(Object parent, int startChildIndex, int stopChildIndex, Object t)

Implements org.antlr.runtime.tree.TreeNodeStream.replaceChildren.

Doc from org.antlr.runtime.tree.TreeNodeStream.replaceChildren.

Replace children of parent from index startChildIndex to stopChildIndex with t, which might be a list. Number of children may be different after this call. The stream is notified because it is walking the tree and might need to know you are monkeying with the underlying tree. Also, it might be able to modify the node stream to avoid restreaming for future phases.

If parent is null, don't do anything; must be at root of overall tree. Can't replace whatever points to the parent externally. Do nothing.

Annotations
@Override
resetback to summary
public void reset()

Implements org.antlr.runtime.tree.TreeNodeStream.reset.

Doc from org.antlr.runtime.tree.TreeNodeStream.reset.

Reset the tree node stream in such a way that it acts like a freshly constructed stream.

Annotations
@Override
rewindback to summary
public void rewind(int marker)

Implements org.antlr.runtime.IntStream.rewind.

Doc from org.antlr.runtime.IntStream.rewind.

Reset the stream so that next call to index would return marker. The marker will usually be index() but it doesn't have to be. It's just a marker to indicate what state the stream was in. This is essentially calling release() and seek(). If there are markers created after this marker argument, this routine must unroll them like a stack. Assume the state the stream was in when this marker was created.

Annotations
@Override
rewindback to summary
public void rewind()

Implements org.antlr.runtime.IntStream.rewind.

Doc from org.antlr.runtime.IntStream.rewind.

Rewind to the input position of the last marker. Used currently only after a cyclic DFA and just before starting a sem/syn predicate to get the input position back to the start of the decision. Do not "pop" the marker off the state. mark(i) and rewind(i) should balance still. It is like invoking rewind(last marker) but it should not "pop" the marker off. It's like seek(last marker's input position).

Annotations
@Override
seekback to summary
public void seek(int index)

Implements org.antlr.runtime.IntStream.seek.

Doc from org.antlr.runtime.IntStream.seek.

Set the input cursor to the position indicated by index. This is normally used to seek ahead in the input stream. No buffering is required to do this unless you know your stream will use seek to move backwards such as when backtracking. This is different from rewind in its multi-directional requirement and in that its argument is strictly an input cursor (index). For char streams, seeking forward must update the stream state such as line number. For seeking backwards, you will be presumably backtracking using the mark/rewind mechanism that restores state and so this method does not need to update state when seeking backwards. Currently, this method is only used for efficient backtracking using memoization, but in the future it may be used for incremental parsing. The index is 0..n-1. A seek to position i means that LA(1) will return the ith symbol. So, seeking to 0 means LA(1) will return the first element in the stream.

Annotations
@Override
setTokenStreamback to summary
public void setTokenStream(TokenStream tokens)
setTreeAdaptorback to summary
public void setTreeAdaptor(TreeAdaptor adaptor)
setUniqueNavigationNodesback to summary
public void setUniqueNavigationNodes(boolean uniqueNavigationNodes)

Implements org.antlr.runtime.tree.TreeNodeStream.setUniqueNavigationNodes.

Doc from org.antlr.runtime.tree.TreeNodeStream.setUniqueNavigationNodes.

As we flatten the tree, we use Token#UP, Token#DOWN nodes to represent the tree structure. When debugging we need unique nodes so we have to instantiate new ones. When doing normal tree parsing, it's slow and a waste of memory to create unique navigation nodes. Default should be false.

Annotations
@Override
sizeback to summary
public int size()

Implements org.antlr.runtime.IntStream.size.

Doc from org.antlr.runtime.IntStream.size.

Only makes sense for streams that buffer everything up probably, but might be useful to display the entire stream or for testing. This value includes a single EOF.

Annotations
@Override
toStringback to summary
public String toString(Object start, Object stop)

Implements org.antlr.runtime.tree.TreeNodeStream.toString.

Doc from org.antlr.runtime.tree.TreeNodeStream.toString.

Return the text of all nodes from start to stop, inclusive. If the stream does not buffer all the nodes then it can still walk recursively from start until stop. You can always return null or "" too, but users should not access $ruleLabel.text in an action of course in that case.

Annotations
@Override
toTokenStringback to summary
public String toTokenString(int start, int stop)

Debugging

toTokenTypeStringback to summary
public String toTokenTypeString()

Used for testing, just return the token type stream

org.antlr.runtime.tree back to summary

protected Class BufferedTreeNodeStream.StreamIterator

extends Object
implements Iterator<Object>
Class Inheritance
All Implemented Interfaces
java.util.Iterator

Field Summary

Modifier and TypeField and Description
pack-priv int
i

Constructor Summary

AccessConstructor and Description
protected

Method Summary

Modifier and TypeMethod and Description
public boolean
hasNext()

Implements java.util.Iterator.hasNext.

Returns true if the iteration has more elements.
public Object
next()

Implements java.util.Iterator.next.

Returns the next element in the iteration.
public void
remove()

Overrides default java.util.Iterator.remove.

Removes from the underlying collection the last element returned by this iterator (optional operation).
Inherited from java.lang.Object:
cloneequalsfinalizegetClasshashCodenotifynotifyAlltoStringwaitwaitwait

Field Detail

iback to summary
pack-priv int i

Constructor Detail

StreamIteratorback to summary
protected StreamIterator()

Method Detail

hasNextback to summary
public boolean hasNext()

Implements java.util.Iterator.hasNext.

Doc from java.util.Iterator.hasNext.

Returns true if the iteration has more elements. (In other words, returns true if next would return an element rather than throwing an exception.)

Returns:boolean

true if the iteration has more elements

Annotations
@Override
nextback to summary
public Object next()

Implements java.util.Iterator.next.

Doc from java.util.Iterator.next.

Returns the next element in the iteration.

Returns:Object

the next element in the iteration

Annotations
@Override
removeback to summary
public void remove()

Overrides default java.util.Iterator.remove.

Doc from java.util.Iterator.remove.

Removes from the underlying collection the last element returned by this iterator (optional operation). This method can be called only once per call to next.

The behavior of an iterator is unspecified if the underlying collection is modified while the iteration is in progress in any way other than by calling this method, unless an overriding class has specified a concurrent modification policy.

The behavior of an iterator is unspecified if this method is called after a call to the forEachRemaining method.

Annotations
@Override