public class TreeNormalizer extends Object implements Serializable
TreeNormalizermay wish to perform is interning the
Strings passed to it. Can be reused as a Singleton. Designed to be extended.
TreeNormalizermethods are in two groups. The contract for this class is that first normalizeTerminal or normalizeNonterminal will be called on each
Stringthat will be put into a
Tree, when they are read from files or otherwise created. Then
normalizeWholeTreewill be called on the
Tree. It normally walks the
Treemaking whatever modifications it wishes to. A
TreeNormalizerneed not make a deep copy of a
Tree. It is assumed to be able to work destructively, because afterwards we will only use the normalized
|Constructor and Description|
|Modifier and Type||Method and Description|
Normalizes a nonterminal contents (and maybe intern it).
Normalizes a leaf contents (and maybe intern it).
Normalize a whole tree -- this method assumes that the argument that it is passed is the root of a complete
leaf- The String that decorates the leaf
category- The String that decorates this nonterminal node
public Tree normalizeWholeTree(Tree tree, TreeFactory tf)
Tree. It is normally implemented as a Tree-walking routine.
This method may return
null. This is interpreted to
mean that this is a tree that should not be included in further
processing. PennTreeReader recognizes this return value, and
asks for another Tree from the input Reader.
tree- The tree to be normalized
tf- the TreeFactory to create new nodes (if needed)
Stanford NLP Group