antlr3.tree.TreeAdaptor Class Reference

Abstract baseclass for tree adaptors. More...

Inheritance diagram for antlr3.tree.TreeAdaptor:

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List of all members.

Public Member Functions

def createWithPayload
 Create a tree node from Token object; for CommonTree type trees, then the token just becomes the payload.
def dupNode
 Duplicate a single tree node.
def dupTree
 Duplicate tree recursively, using dupNode() for each node.
def nil
 Return a nil node (an empty but non-null node) that can hold a list of element as the children.
def errorNode
 Return a tree node representing an error.
def isNil
 Is tree considered a nil node used to make lists of child nodes?
def addChild
 Add a child to the tree t.
def becomeRoot
 If oldRoot is a nil root, just copy or move the children to newRoot.
def rulePostProcessing
 Given the root of the subtree created for this rule, post process it to do any simplifications or whatever you want.
def getUniqueID
 For identifying trees.
def createFromToken
 Create a new node derived from a token, with a new token type and (optionally) new text.
def createFromType
 Create a new node derived from a token, with a new token type.
def getType
 For tree parsing, I need to know the token type of a node.
def setType
 Node constructors can set the type of a node.
def getText
def setText
 Node constructors can set the text of a node.
def getToken
 Return the token object from which this node was created.
def setTokenBoundaries
 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.
def getTokenStartIndex
 Get the token start index for this subtree; return -1 if no such index.
def getTokenStopIndex
 Get the token stop index for this subtree; return -1 if no such index.
def getChild
 Get a child 0.
def setChild
 Set ith child (0.
def deleteChild
 Remove ith child and shift children down from right.
def getChildCount
 How many children? If 0, then this is a leaf node.
def getParent
 Who is the parent node of this node; if null, implies node is root.
def setParent
 Who is the parent node of this node; if null, implies node is root.
def getChildIndex
 What index is this node in the child list? Range: 0.
def setChildIndex
 What index is this node in the child list? Range: 0.
def replaceChildren
 Replace from start to stop child index of parent with t, which might be a list.
def create
 Deprecated, use createWithPayload, createFromToken or createFromType.


Detailed Description

Abstract baseclass for tree adaptors.

How to create and navigate trees. Rather than have a separate factory and adaptor, I've merged them. Makes sense to encapsulate.

This takes the place of the tree construction code generated in the generated code in 2.x and the ASTFactory.

I do not need to know the type of a tree at all so they are all generic Objects. This may increase the amount of typecasting needed. :(

Definition at line 304 of file tree.py.


Member Function Documentation

def antlr3.tree.TreeAdaptor.createWithPayload (   self,
  payload 
)

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.

Reimplemented in antlr3.tree.CommonTreeAdaptor.

Definition at line 316 of file tree.py.

def antlr3.tree.TreeAdaptor.dupNode (   self,
  treeNode 
)

Duplicate a single tree node.

Override if you want another kind of node to be built.

Reimplemented in antlr3.tree.CommonTreeAdaptor.

Definition at line 325 of file tree.py.

def antlr3.tree.TreeAdaptor.dupTree (   self,
  tree 
)

Duplicate tree recursively, using dupNode() for each node.

Definition at line 332 of file tree.py.

def antlr3.tree.TreeAdaptor.nil (   self  ) 

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);"

Reimplemented in antlr3.tree.BaseTreeAdaptor.

Definition at line 343 of file tree.py.

def antlr3.tree.TreeAdaptor.errorNode (   self,
  input,
  start,
  stop,
  exc 
)

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.

Reimplemented in antlr3.tree.BaseTreeAdaptor.

Definition at line 364 of file tree.py.

def antlr3.tree.TreeAdaptor.isNil (   self,
  tree 
)

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

Reimplemented in antlr3.tree.BaseTreeAdaptor.

Definition at line 371 of file tree.py.

def antlr3.tree.TreeAdaptor.addChild (   self,
  t,
  child 
)

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.

Reimplemented in antlr3.tree.BaseTreeAdaptor.

Definition at line 385 of file tree.py.

def antlr3.tree.TreeAdaptor.becomeRoot (   self,
  newRoot,
  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.

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.

Reimplemented in antlr3.tree.BaseTreeAdaptor.

Definition at line 418 of file tree.py.

def antlr3.tree.TreeAdaptor.rulePostProcessing (   self,
  root 
)

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().

Reimplemented in antlr3.tree.BaseTreeAdaptor.

Definition at line 438 of file tree.py.

def antlr3.tree.TreeAdaptor.getUniqueID (   self,
  node 
)

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.

Reimplemented in antlr3.tree.BaseTreeAdaptor.

Definition at line 450 of file tree.py.

def antlr3.tree.TreeAdaptor.createFromToken (   self,
  tokenType,
  fromToken,
  text = None 
)

Create a new node derived from a token, with a new token type and (optionally) new text.

This is invoked from an imaginary node ref on right side of a rewrite rule as IMAG[$tokenLabel] or IMAG[$tokenLabel "IMAG"].

This should invoke createToken(Token).

Reimplemented in antlr3.tree.BaseTreeAdaptor.

Definition at line 467 of file tree.py.

def antlr3.tree.TreeAdaptor.createFromType (   self,
  tokenType,
  text 
)

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).

Reimplemented in antlr3.tree.BaseTreeAdaptor.

Definition at line 480 of file tree.py.

def antlr3.tree.TreeAdaptor.getType (   self,
  t 
)

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

Reimplemented in antlr3.tree.BaseTreeAdaptor, and antlr3.tree.CommonTreeAdaptor.

Definition at line 489 of file tree.py.

def antlr3.tree.TreeAdaptor.setType (   self,
  t,
  type 
)

Node constructors can set the type of a node.

Reimplemented in antlr3.tree.BaseTreeAdaptor.

Definition at line 496 of file tree.py.

def antlr3.tree.TreeAdaptor.getText (   self,
  t 
)

Reimplemented in antlr3.tree.BaseTreeAdaptor, and antlr3.tree.CommonTreeAdaptor.

Definition at line 501 of file tree.py.

def antlr3.tree.TreeAdaptor.setText (   self,
  t,
  text 
)

Node constructors can set the text of a node.

Reimplemented in antlr3.tree.BaseTreeAdaptor.

Definition at line 506 of file tree.py.

def antlr3.tree.TreeAdaptor.getToken (   self,
  t 
)

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().

Reimplemented in antlr3.tree.CommonTreeAdaptor.

Definition at line 522 of file tree.py.

def antlr3.tree.TreeAdaptor.setTokenBoundaries (   self,
  t,
  startToken,
  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.

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.

Reimplemented in antlr3.tree.CommonTreeAdaptor.

Definition at line 535 of file tree.py.

def antlr3.tree.TreeAdaptor.getTokenStartIndex (   self,
  t 
)

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

Reimplemented in antlr3.tree.CommonTreeAdaptor.

Definition at line 544 of file tree.py.

def antlr3.tree.TreeAdaptor.getTokenStopIndex (   self,
  t 
)

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

Reimplemented in antlr3.tree.CommonTreeAdaptor.

Definition at line 553 of file tree.py.

def antlr3.tree.TreeAdaptor.getChild (   self,
  t,
  i 
)

Get a child 0.

.n-1 node

Reimplemented in antlr3.tree.BaseTreeAdaptor, and antlr3.tree.CommonTreeAdaptor.

Definition at line 562 of file tree.py.

def antlr3.tree.TreeAdaptor.setChild (   self,
  t,
  i,
  child 
)

Set ith child (0.

.n-1) to t; t must be non-null and non-nil node

Reimplemented in antlr3.tree.BaseTreeAdaptor.

Definition at line 569 of file tree.py.

def antlr3.tree.TreeAdaptor.deleteChild (   self,
  t,
  i 
)

Remove ith child and shift children down from right.

Reimplemented in antlr3.tree.BaseTreeAdaptor.

Definition at line 576 of file tree.py.

def antlr3.tree.TreeAdaptor.getChildCount (   self,
  t 
)

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

Reimplemented in antlr3.tree.BaseTreeAdaptor, and antlr3.tree.CommonTreeAdaptor.

Definition at line 583 of file tree.py.

def antlr3.tree.TreeAdaptor.getParent (   self,
  t 
)

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.

Reimplemented in antlr3.tree.CommonTreeAdaptor.

Definition at line 594 of file tree.py.

def antlr3.tree.TreeAdaptor.setParent (   self,
  t,
  parent 
)

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.

Reimplemented in antlr3.tree.CommonTreeAdaptor.

Definition at line 605 of file tree.py.

def antlr3.tree.TreeAdaptor.getChildIndex (   self,
  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.

Reimplemented in antlr3.tree.CommonTreeAdaptor.

Definition at line 616 of file tree.py.

def antlr3.tree.TreeAdaptor.setChildIndex (   self,
  t,
  index 
)

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.

Reimplemented in antlr3.tree.CommonTreeAdaptor.

Definition at line 627 of file tree.py.

def antlr3.tree.TreeAdaptor.replaceChildren (   self,
  parent,
  startChildIndex,
  stopChildIndex,
  t 
)

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.

Reimplemented in antlr3.tree.CommonTreeAdaptor.

Definition at line 641 of file tree.py.

def antlr3.tree.TreeAdaptor.create (   self,
  args 
)

Deprecated, use createWithPayload, createFromToken or createFromType.

This method only exists to mimic the Java interface of TreeAdaptor.

Definition at line 655 of file tree.py.


The documentation for this class was generated from the following file:

Generated on Mon Nov 29 17:24:29 2010 for ANTLR Python API by  doxygen 1.5.5