Package org.antlr.runtime.tree
Interface TreeNodeStream
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- All Superinterfaces:
IntStream
- All Known Implementing Classes:
BufferedTreeNodeStream
,CommonTreeNodeStream
,DebugTreeNodeStream
public interface TreeNodeStream extends IntStream
A stream of tree nodes, accessing nodes from a tree of some kind
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Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description Object
get(int i)
Get a tree node at an absolute indexi
; 0..n-1.TokenStream
getTokenStream()
If the tree associated with this stream was created from aTokenStream
, you can specify it here.TreeAdaptor
getTreeAdaptor()
What adaptor can tell me how to interpret/navigate nodes and trees.Object
getTreeSource()
Where is this stream pulling nodes from? This is not the name, but the object that provides node objects.Object
LT(int k)
Get tree node at current input pointer +k
ahead wherek==1
is next node.void
replaceChildren(Object parent, int startChildIndex, int stopChildIndex, Object t)
Replace children ofparent
from indexstartChildIndex
tostopChildIndex
witht
, which might be a list.void
reset()
Reset the tree node stream in such a way that it acts like a freshly constructed stream.void
setUniqueNavigationNodes(boolean uniqueNavigationNodes)
As we flatten the tree, we useToken.UP
,Token.DOWN
nodes to represent the tree structure.String
toString(Object start, Object stop)
Return the text of all nodes fromstart
tostop
, inclusive.
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Method Detail
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get
Object get(int i)
Get a tree node at an absolute indexi
; 0..n-1. If you don't want to buffer up nodes, then this method makes no sense for you.
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LT
Object LT(int k)
Get tree node at current input pointer +k
ahead wherek==1
is next node.k<0
indicates nodes in the past. SoLT(-1)
is previous node, but implementations are not required to provide results fork < -1
.LT(0)
is undefined. Fork<=n
, returnnull
. Returnnull
forLT(0)
and any index that results in an absolute address that is negative.This is analogous to
TokenStream.LT(int)
, but this returns a tree node instead of aToken
. Makes code generation identical for both parser and tree grammars.
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getTreeSource
Object getTreeSource()
Where is this stream pulling nodes from? This is not the name, but the object that provides node objects.
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getTokenStream
TokenStream getTokenStream()
If the tree associated with this stream was created from aTokenStream
, you can specify it here. Used to do rule$text
attribute in tree parser. Optional unless you use tree parser rule$text
attribute oroutput=template
andrewrite=true
options.
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getTreeAdaptor
TreeAdaptor getTreeAdaptor()
What adaptor can tell me how to interpret/navigate nodes and trees. E.g., get text of a node.
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setUniqueNavigationNodes
void setUniqueNavigationNodes(boolean uniqueNavigationNodes)
As we flatten the tree, we useToken.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 befalse
.
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reset
void reset()
Reset the tree node stream in such a way that it acts like a freshly constructed stream.
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toString
String toString(Object start, Object stop)
Return the text of all nodes fromstart
tostop
, inclusive. If the stream does not buffer all the nodes then it can still walk recursively from start until stop. You can always returnnull
or""
too, but users should not access$ruleLabel.text
in an action of course in that case.
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replaceChildren
void replaceChildren(Object parent, int startChildIndex, int stopChildIndex, Object t)
Replace children ofparent
from indexstartChildIndex
tostopChildIndex
witht
, 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
isnull
, don't do anything; must be at root of overall tree. Can't replace whatever points to the parent externally. Do nothing.
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