org.antlr.runtime.debug

Class DebugTreeAdaptor

java.lang.Object

org.antlr.runtime.debug.DebugTreeAdaptor

All Implemented Interfaces:

TreeAdaptor

public class DebugTreeAdaptor
extends Object
implements TreeAdaptor

A TreeAdaptor proxy that fires debugging events to a DebugEventListener delegate and uses the TreeAdaptor delegate to do the actual work. All AST events are triggered by this adaptor; no code gen changes are needed in generated rules. Debugging events are triggered *after* invoking tree adaptor routines. Trees created with actions in rewrite actions like "-> ^(ADD {foo} {bar})" cannot be tracked as they might not use the adaptor to create foo, bar. The debug listener has to deal with tree node IDs for which it did not see a createNode event. A single node is sufficient even if it represents a whole tree.

Field Summary

Fields

Modifier and Type	Field and Description
protected TreeAdaptor	adaptor
protected DebugEventListener	dbg

Constructor Summary

Constructors

Constructor and Description
DebugTreeAdaptor(DebugEventListener dbg, TreeAdaptor adaptor)

Method Summary

Methods

Modifier and Type	Method and Description
void	addChild(Object t, Object child) Add a child to the tree t.
void	addChild(Object t, Token child)
Object	becomeRoot(Object newRoot, Object oldRoot) If oldRoot is a nil root, just copy or move the children to newRoot.
Object	becomeRoot(Token newRoot, Object oldRoot) Create a node for newRoot make it the root of oldRoot.
Object	create(int tokenType, String text) Create a new node derived from a token, with a new token type.
Object	create(int tokenType, Token fromToken) Create a new node derived from a token, with a new token type.
Object	create(int tokenType, Token fromToken, String text) Same as create(tokenType,fromToken) except set the text too.
Object	create(Token payload) Create a tree node from Token object; for CommonTree type trees, then the token just becomes the payload.
Object	deleteChild(Object t, int i) Remove ith child and shift children down from right.
Object	dupNode(Object treeNode) Duplicate a single tree node.
Object	dupTree(Object tree) Duplicate tree recursively, using dupNode() for each node
Object	errorNode(TokenStream input, Token start, Token stop, RecognitionException e) Return a tree node representing an error.
Object	getChild(Object t, int i) Get a child 0..n-1 node
int	getChildCount(Object t) How many children? If 0, then this is a leaf node
int	getChildIndex(Object t) What index is this node in the child list? Range: 0..n-1 If your node type doesn't handle this, it's ok but the tree rewrites in tree parsers need this functionality.
DebugEventListener	getDebugListener()
Object	getParent(Object t) Who is the parent node of this node; if null, implies node is root.
String	getText(Object t)
Token	getToken(Object t) Return the token object from which this node was created.
int	getTokenStartIndex(Object t) Get the token start index for this subtree; return -1 if no such index
int	getTokenStopIndex(Object t) Get the token stop index for this subtree; return -1 if no such index
TreeAdaptor	getTreeAdaptor()
int	getType(Object t) For tree parsing, I need to know the token type of a node
int	getUniqueID(Object node) For identifying trees.
boolean	isNil(Object tree) Is tree considered a nil node used to make lists of child nodes?
Object	nil() Return a nil node (an empty but non-null node) that can hold a list of element as the children.
void	replaceChildren(Object parent, int startChildIndex, int stopChildIndex, Object t) Replace from start to stop child index of parent with t, which might be a list.
Object	rulePostProcessing(Object root) Given the root of the subtree created for this rule, post process it to do any simplifications or whatever you want.
void	setChild(Object t, int i, Object child) Set ith child (0..n-1) to t; t must be non-null and non-nil node
void	setChildIndex(Object t, int index)
void	setDebugListener(DebugEventListener dbg)
void	setParent(Object t, Object parent)
void	setText(Object t, String text) Node constructors can set the text of a node
void	setTokenBoundaries(Object t, Token startToken, Token stopToken) Where are the bounds in the input token stream for this node and all children? Each rule that creates AST nodes will call this method right before returning.
void	setType(Object t, int type) Node constructors can set the type of a node
protected void	simulateTreeConstruction(Object t) ^(A B C): emit create A, create B, add child, ...

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

dbg

protected DebugEventListener dbg

adaptor

protected TreeAdaptor adaptor

Constructor Detail

DebugTreeAdaptor

public DebugTreeAdaptor(DebugEventListener dbg,
                TreeAdaptor adaptor)

Method Detail

create

public Object create(Token payload)

Description copied from interface: TreeAdaptor

Create a tree node from Token object; for CommonTree type trees, then the token just becomes the payload. This is the most common create call. Override if you want another kind of node to be built.

Specified by:

create in interface TreeAdaptor

errorNode

public Object errorNode(TokenStream input,
               Token start,
               Token stop,
               RecognitionException e)

Description copied from interface: TreeAdaptor

Return a tree node representing an error. This node records the tokens consumed during error recovery. The start token indicates the input symbol at which the error was detected. The stop token indicates the last symbol consumed during recovery. You must specify the input stream so that the erroneous text can be packaged up in the error node. The exception could be useful to some applications; default implementation stores ptr to it in the CommonErrorNode. This only makes sense during token parsing, not tree parsing. Tree parsing should happen only when parsing and tree construction succeed.

Specified by:

errorNode in interface TreeAdaptor

dupTree

public Object dupTree(Object tree)

Description copied from interface: TreeAdaptor

Duplicate tree recursively, using dupNode() for each node

Specified by:

dupTree in interface TreeAdaptor

simulateTreeConstruction

protected void simulateTreeConstruction(Object t)

^(A B C): emit create A, create B, add child, ...

dupNode

public Object dupNode(Object treeNode)

Description copied from interface: TreeAdaptor

Duplicate a single tree node. Override if you want another kind of node to be built.

Specified by:

dupNode in interface TreeAdaptor

nil

public Object nil()

Description copied from interface: TreeAdaptor

Return a nil node (an empty but non-null node) that can hold a list of element as the children. If you want a flat tree (a list) use "t=adaptor.nil(); t.addChild(x); t.addChild(y);"

Specified by:

nil in interface TreeAdaptor

isNil

public boolean isNil(Object tree)

Description copied from interface: TreeAdaptor

Is tree considered a nil node used to make lists of child nodes?

Specified by:

isNil in interface TreeAdaptor

addChild

public void addChild(Object t,
            Object child)

Description copied from interface: TreeAdaptor

Add a child to the tree t. If child is a flat tree (a list), make all in list children of t. Warning: if t has no children, but child does and child isNil then you can decide it is ok to move children to t via t.children = child.children; i.e., without copying the array. Just make sure that this is consistent with have the user will build ASTs. Do nothing if t or child is null.

Specified by:

addChild in interface TreeAdaptor

becomeRoot

public Object becomeRoot(Object newRoot,
                Object oldRoot)

Description copied from interface: TreeAdaptor

If oldRoot is a nil root, just copy or move the children to newRoot. If not a nil root, make oldRoot a child of newRoot. old=^(nil a b c), new=r yields ^(r a b c) old=^(a b c), new=r yields ^(r ^(a b c)) If newRoot is a nil-rooted single child tree, use the single child as the new root node. old=^(nil a b c), new=^(nil r) yields ^(r a b c) old=^(a b c), new=^(nil r) yields ^(r ^(a b c)) If oldRoot was null, it's ok, just return newRoot (even if isNil). old=null, new=r yields r old=null, new=^(nil r) yields ^(nil r) Return newRoot. Throw an exception if newRoot is not a simple node or nil root with a single child node--it must be a root node. If newRoot is ^(nil x) return x as newRoot. Be advised that it's ok for newRoot to point at oldRoot's children; i.e., you don't have to copy the list. We are constructing these nodes so we should have this control for efficiency.

Specified by:

becomeRoot in interface TreeAdaptor

rulePostProcessing

public Object rulePostProcessing(Object root)

Description copied from interface: TreeAdaptor

Given the root of the subtree created for this rule, post process it to do any simplifications or whatever you want. A required behavior is to convert ^(nil singleSubtree) to singleSubtree as the setting of start/stop indexes relies on a single non-nil root for non-flat trees. Flat trees such as for lists like "idlist : ID+ ;" are left alone unless there is only one ID. For a list, the start/stop indexes are set in the nil node. This method is executed after all rule tree construction and right before setTokenBoundaries().

Specified by:

rulePostProcessing in interface TreeAdaptor

addChild

public void addChild(Object t,
            Token child)

becomeRoot

public Object becomeRoot(Token newRoot,
                Object oldRoot)

Description copied from interface: TreeAdaptor

Create a node for newRoot make it the root of oldRoot. If oldRoot is a nil root, just copy or move the children to newRoot. If not a nil root, make oldRoot a child of newRoot. Return node created for newRoot. Be advised: when debugging ASTs, the DebugTreeAdaptor manually calls create(Token child) and then plain becomeRoot(node, node) because it needs to trap calls to create, but it can't since it delegates to not inherits from the TreeAdaptor.

Specified by:

becomeRoot in interface TreeAdaptor

create

public Object create(int tokenType,
            Token fromToken)

Description copied from interface: TreeAdaptor

Create a new node derived from a token, with a new token type. This is invoked from an imaginary node ref on right side of a rewrite rule as IMAG[$tokenLabel]. This should invoke createToken(Token).

Specified by:

create in interface TreeAdaptor

create

public Object create(int tokenType,
            Token fromToken,
            String text)

Description copied from interface: TreeAdaptor

Same as create(tokenType,fromToken) except set the text too. This is invoked from an imaginary node ref on right side of a rewrite rule as IMAG[$tokenLabel, "IMAG"]. This should invoke createToken(Token).

Specified by:

create in interface TreeAdaptor

create

public Object create(int tokenType,
            String text)

Description copied from interface: TreeAdaptor

Create a new node derived from a token, with a new token type. This is invoked from an imaginary node ref on right side of a rewrite rule as IMAG["IMAG"]. This should invoke createToken(int,String).

Specified by:

create in interface TreeAdaptor

getType

public int getType(Object t)

Description copied from interface: TreeAdaptor

For tree parsing, I need to know the token type of a node

Specified by:

getType in interface TreeAdaptor

setType

public void setType(Object t,
           int type)

Description copied from interface: TreeAdaptor

Node constructors can set the type of a node

Specified by:

setType in interface TreeAdaptor

getText

public String getText(Object t)

Specified by:

getText in interface TreeAdaptor

setText

public void setText(Object t,
           String text)

Description copied from interface: TreeAdaptor

Node constructors can set the text of a node

Specified by:

setText in interface TreeAdaptor

getToken

public Token getToken(Object t)

Description copied from interface: TreeAdaptor

Return the token object from which this node was created. Currently used only for printing an error message. The error display routine in BaseRecognizer needs to display where the input the error occurred. If your tree of limitation does not store information that can lead you to the token, you can create a token filled with the appropriate information and pass that back. See BaseRecognizer.getErrorMessage().

Specified by:

getToken in interface TreeAdaptor

setTokenBoundaries

public void setTokenBoundaries(Object t,
                      Token startToken,
                      Token stopToken)

Description copied from interface: TreeAdaptor

Where are the bounds in the input token stream for this node and all children? Each rule that creates AST nodes will call this method right before returning. Flat trees (i.e., lists) will still usually have a nil root node just to hold the children list. That node would contain the start/stop indexes then.

Specified by:

setTokenBoundaries in interface TreeAdaptor

getTokenStartIndex

public int getTokenStartIndex(Object t)

Description copied from interface: TreeAdaptor

Get the token start index for this subtree; return -1 if no such index

Specified by:

getTokenStartIndex in interface TreeAdaptor

getTokenStopIndex

public int getTokenStopIndex(Object t)

Description copied from interface: TreeAdaptor

Get the token stop index for this subtree; return -1 if no such index

Specified by:

getTokenStopIndex in interface TreeAdaptor

getChild

public Object getChild(Object t,
              int i)

Description copied from interface: TreeAdaptor

Get a child 0..n-1 node

Specified by:

getChild in interface TreeAdaptor

setChild

public void setChild(Object t,
            int i,
            Object child)

Description copied from interface: TreeAdaptor

Set ith child (0..n-1) to t; t must be non-null and non-nil node

Specified by:

setChild in interface TreeAdaptor

deleteChild

public Object deleteChild(Object t,
                 int i)

Description copied from interface: TreeAdaptor

Remove ith child and shift children down from right.

Specified by:

deleteChild in interface TreeAdaptor

getChildCount

public int getChildCount(Object t)

Description copied from interface: TreeAdaptor

How many children? If 0, then this is a leaf node

Specified by:

getChildCount in interface TreeAdaptor

getUniqueID

public int getUniqueID(Object node)

Description copied from interface: TreeAdaptor

For identifying trees. How to identify nodes so we can say "add node to a prior node"? Even becomeRoot is an issue. Use System.identityHashCode(node) usually.

Specified by:

getUniqueID in interface TreeAdaptor

getParent

public Object getParent(Object t)

Description copied from interface: TreeAdaptor

Who is the parent node of this node; if null, implies node is root. If your node type doesn't handle this, it's ok but the tree rewrites in tree parsers need this functionality.

Specified by:

getParent in interface TreeAdaptor

getChildIndex

public int getChildIndex(Object t)

Description copied from interface: TreeAdaptor

What index is this node in the child list? Range: 0..n-1 If your node type doesn't handle this, it's ok but the tree rewrites in tree parsers need this functionality.

Specified by:

getChildIndex in interface TreeAdaptor

setParent

public void setParent(Object t,
             Object parent)

Specified by:

setParent in interface TreeAdaptor

setChildIndex

public void setChildIndex(Object t,
                 int index)

Specified by:

setChildIndex in interface TreeAdaptor

replaceChildren

public void replaceChildren(Object parent,
                   int startChildIndex,
                   int stopChildIndex,
                   Object t)

Description copied from interface: TreeAdaptor

Replace from start to stop child index of parent with t, which might be a list. Number of children may be different after this call. 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.

Specified by:

replaceChildren in interface TreeAdaptor

getDebugListener

public DebugEventListener getDebugListener()

setDebugListener

public void setDebugListener(DebugEventListener dbg)

getTreeAdaptor

public TreeAdaptor getTreeAdaptor()