public interface TreeNodeStream extends IntStream
Modifier and Type | Method and Description |
---|---|
Object |
get(int i)
Get a tree node at an absolute index
i ; 0..n-1. |
TokenStream |
getTokenStream()
If the tree associated with this stream was created from a
TokenStream , 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 where
k==1 is next node. |
void |
replaceChildren(Object parent,
int startChildIndex,
int stopChildIndex,
Object t)
Replace children of
parent from index startChildIndex to
stopChildIndex with t , 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 use
Token.UP , Token.DOWN nodes
to represent the tree structure. |
String |
toString(Object start,
Object stop)
Return the text of all nodes from
start to stop ,
inclusive. |
Object get(int i)
i
; 0..n-1.
If you don't want to buffer up nodes, then this method makes no
sense for you.Object LT(int k)
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(int)
, but this returns a tree node
instead of a Token
. Makes code generation identical for both
parser and tree grammars.
Object getTreeSource()
TokenStream getTokenStream()
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.TreeAdaptor getTreeAdaptor()
void setUniqueNavigationNodes(boolean uniqueNavigationNodes)
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
.void reset()
String toString(Object start, Object stop)
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.void replaceChildren(Object parent, int startChildIndex, int stopChildIndex, Object t)
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.
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