| org.antlr.runtime.tree.TreeAdaptor
All known Subclasses: org.antlr.runtime.tree.BaseTreeAdaptor, org.antlr.runtime.debug.DebugTreeAdaptor,
| TreeAdaptor | | public interface TreeAdaptor (Code) | | 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. :(
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| Method Summary | |
| public void | addChild(Object t, Object child)
Add a child to the tree t. | | public Object | becomeRoot(Object newRoot, Object 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. | | public Object | becomeRoot(Token newRoot, Object oldRoot)
Create a node for newRoot make it the root of oldRoot. | | public Object | create(Token payload)
Create a tree node from Token object; for CommonTree type trees,
then the token just becomes the payload. | | public Object | create(int tokenType, Token fromToken)
Create a new node derived from a token, with a new token type. | | public Object | create(int tokenType, Token fromToken, String text)
Same as create(tokenType,fromToken) except set the text too. | | public Object | create(int tokenType, String text)
Create a new node derived from a token, with a new token type. | | public Object | dupNode(Object treeNode)
| | public Object | dupTree(Object tree)
| | public Object | getChild(Object t, int i)
| | public int | getChildCount(Object t)
| | public String | getText(Object t)
| | public Token | getToken(Object 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. | | public int | getTokenStartIndex(Object t)
| | public int | getTokenStopIndex(Object t)
| | public int | getType(Object t)
| | public int | getUniqueID(Object node)
For identifying trees.
How to identify nodes so we can say "add node to a prior node"?
Even becomeRoot is an issue. | | public boolean | isNil(Object tree)
| | public Object | nil()
Return a nil node (an empty but non-null node) that can hold
a list of element as the children. | | public 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. | | public void | setText(Object t, String text)
| | public 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. | | public void | setType(Object t, int type)
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| addChild | | public void addChild(Object t, Object child)(Code) | | 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.
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| becomeRoot | | public Object becomeRoot(Object newRoot, Object oldRoot)(Code) | | 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.
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| becomeRoot | | public Object becomeRoot(Token newRoot, Object oldRoot)(Code) | | 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.
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| create | | public Object create(Token payload)(Code) | | 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.
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| create | | public Object create(int tokenType, Token fromToken)(Code) | | 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[$tokenLabel].
This should invoke createToken(Token).
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| create | | public Object create(int tokenType, Token fromToken, String text)(Code) | | Same as create(tokenType,fromToken) except set the text too.
This is invoked from an imaginary node ref on right side of a
rewrite rule as IMAG[$tokenLabel, "IMAG"].
This should invoke createToken(Token).
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| create | | public Object create(int tokenType, String text)(Code) | | 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).
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| dupTree | | public Object dupTree(Object tree)(Code) | | Duplicate tree recursively, using dupNode() for each node
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| getChildCount | | public int getChildCount(Object t)(Code) | | How many children? If 0, then this is a leaf node
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| getToken | | public Token getToken(Object t)(Code) | | 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().
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| getTokenStartIndex | | public int getTokenStartIndex(Object t)(Code) | | Get the token start index for this subtree; return -1 if no such index
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| getTokenStopIndex | | public int getTokenStopIndex(Object t)(Code) | | Get the token stop index for this subtree; return -1 if no such index
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| getType | | public int getType(Object t)(Code) | | For tree parsing, I need to know the token type of a node
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| getUniqueID | | public int getUniqueID(Object node)(Code) | | 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.
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| isNil | | public boolean isNil(Object tree)(Code) | | Is tree considered a nil node used to make lists of child nodes?
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| nil | | public Object nil()(Code) | | 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);"
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| rulePostProcessing | | public Object rulePostProcessing(Object root)(Code) | | 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().
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| setText | | public void setText(Object t, String text)(Code) | | Node constructors can set the text of a node
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| setTokenBoundaries | | public void setTokenBoundaries(Object t, Token startToken, Token stopToken)(Code) | | 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.
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| setType | | public void setType(Object t, int type)(Code) | | Node constructors can set the type of a node
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