Class AnnotationIndexImpl<T extends AnnotationFS>

  • All Implemented Interfaces:
    Iterable<T>, FSIndex<T>, AnnotationIndex<T>

    public class AnnotationIndexImpl<T extends AnnotationFS>
    extends Object
    implements AnnotationIndex<T>
    Implementation of annotation indexes. A wrapper not an extend, because the constructor argument index has customization for additional fns and a ref to it's enclosing instance of the FSIndexRepositoryImpl.
    • Constructor Detail

      • AnnotationIndexImpl

        public AnnotationIndexImpl​(FSIndex<T> index)
    • Method Detail

      • size

        public int size()
        Description copied from interface: FSIndex
        Return the number of feature structures in this index.
        Specified by:
        size in interface FSIndex<T extends AnnotationFS>
        Returns:
        The number of FSs in this index.
      • getType

        public Type getType()
        Description copied from interface: FSIndex
        Return the type of feature structures this index contains.
        Specified by:
        getType in interface FSIndex<T extends AnnotationFS>
        Returns:
        The type of feature structures in this index.
      • contains

        public boolean contains​(FeatureStructure fs)
        Description copied from interface: FSIndex
        Check if the index contains an element equal to the given feature structure according to the comparators defined for this index. For bag indexes (which have no comparators), the equality test means the identical feature structure. Note that this is in general not the same as feature structure identity.
        Specified by:
        contains in interface FSIndex<T extends AnnotationFS>
        Parameters:
        fs - A Feature Structure used a template to match for equality with the FSs in the index.
        Returns:
        true if the index contains such an element.
      • find

        public FeatureStructure find​(FeatureStructure fs)
        Description copied from interface: FSIndex
        Find an entry in the index "equal to" the given feature structure according to the comparators specified for this index. Note that this is in general not the same as feature structure identity. For BAG indexes, it is identity, for others it means the found feature structure compares equal with the parameter in terms of the defined comparators for the index.
        Specified by:
        find in interface FSIndex<T extends AnnotationFS>
        Parameters:
        fs - A Feature Structure used a template to match with the Feature Structures in the index.
        Returns:
        A FS equal to the template argument, or null if no such FS exists.
        See Also:
        FSIterator.moveTo(FeatureStructure)
      • compare

        public int compare​(FeatureStructure fs1,
                           FeatureStructure fs2)
        Description copied from interface: FSIndex
        Compare two feature structures according to the ordering relation of the index. If the input feature structures are not of the type of the index, the result is undefined.
        Specified by:
        compare in interface FSIndex<T extends AnnotationFS>
        Parameters:
        fs1 - the first Feature Structure to compare
        fs2 - the second Feature Structure to compare
        Returns:
        -1 if fs1 < fs2; 0 if fs1 = fs2; 1 else.
      • iterator

        public FSIterator<T> iterator​(FeatureStructure fs)
        Description copied from interface: FSIndex
        Return an iterator over the index. The position of the iterator will be set such that the feature structure returned by a call to the iterator's get() method is greater than or equal to fs, and any previous FS is less than FS (the iterator is positioned at the earliest of equal values). If no such position exists, the iterator will be invalid.
        Specified by:
        iterator in interface FSIndex<T extends AnnotationFS>
        Parameters:
        fs - The feature structure at which the iterator should be positioned.
        Returns:
        An iterator positioned at fs, if it exists. An invalid iterator, else.
      • getIndexingStrategy

        public int getIndexingStrategy()
        Description copied from interface: FSIndex
        Return the indexing strategy.
        Specified by:
        getIndexingStrategy in interface FSIndex<T extends AnnotationFS>
        Returns:
        One of SORTED_INDEX, BAG_INDEX or SET_INDEX.
      • iterator

        public FSIterator<T> iterator​(boolean ambiguous)
        Description copied from interface: AnnotationIndex
        Return an iterator over annotations that can be constrained to be unambiguous.

        A disambiguated iterator is defined as follows. The first annotation returned is the same as would be returned by the corresponding ambiguous iterator. If the unambiguous iterator has returned a previously, it will next return the smallest b s.t. a < b and a.getEnd() <= b.getBegin(). In other words, the b annotation's start will be large enough to not overlap the span of a.

        An unambiguous iterator makes a snapshot copy of the index containing just the disambiguated items, and iterates over that. It doesn't check for concurrent index modifications (the ambiguous iterator does check for this).

        Specified by:
        iterator in interface AnnotationIndex<T extends AnnotationFS>
        Parameters:
        ambiguous - If set to false, iterator will be unambiguous.
        Returns:
        A annotation iterator.
      • subiterator

        public FSIterator<T> subiterator​(AnnotationFS annot)
        Description copied from interface: AnnotationIndex
        Return a subiterator whose bounds are defined by the input annotation.

        The annot is used for 3 purposes:

        • It is used to compute the position in the index where the iteration starts.
        • It is used to compute end point where the iterator stops when moving forward.
        • It is used to specify which annotations will be skipped while iterating.

        The starting position is computed by first finding a position whose annotation compares equal with the annot (this might be one of several), and then advancing until reaching a position where the annotation there is not equal to the annot. If no item in the index is equal (meaning it has the same begin, the same end, and is the same type as the annot) then the iterator is positioned to the first annotation which is greater than the annot, or if there are no annotations greater than the annot, the iterator is marked invalid.

        The iterator will stop (become invalid) when

        • it runs out of items in the index going forward or backwards, or
        • while moving forward, it reaches a point where the annotation at that position has a start is beyond the annot's end position, or
        • while moving backwards, it reaches a position in front of its original starting position.

        While iterating, it operates like a strict iterator; annotations whose end positions are > the end position of annot are skipped.

        This is equivalent to returning annotations b such that

        • annot < b, and
        • annot.getEnd() >= b.getBegin(), skipping b's whose end position is > annot.getEnd().

        For annotations x, y, x < y here is to be interpreted as "x comes before y in the index", according to the rules defined in the description of this class.

        This definition implies that annotations b that have the same span as annot may or may not be returned by the subiterator. This is determined by the type priorities; the subiterator will only return such an annotation b if the type of annot precedes the type of b in the type priorities definition. If you have not specified the priority, or if annot and b are of the same type, then the behavior is undefined.

        For example, if you have an annotation S of type Sentence and an annotation P of type Paragraph that have the same span, and you have defined Paragraph before Sentence in your type priorities, then subiterator(P) will give you an iterator that will return S, but subiterator(S) will give you an iterator that will NOT return P. The intuition is that a Paragraph is conceptually larger than a Sentence, as defined by the type priorities.

        Calling subiterator(a) is equivalent to calling subiterator(a, true, true).. See subiterator(AnnotationFS, boolean, boolean).

        Specified by:
        subiterator in interface AnnotationIndex<T extends AnnotationFS>
        Parameters:
        annot - Defines the boundaries of the subiterator.
        Returns:
        A subiterator.
      • subiterator

        public FSIterator<T> subiterator​(AnnotationFS annot,
                                         boolean ambiguous,
                                         boolean strict)
        Description copied from interface: AnnotationIndex
        Return a subiterator whose bounds are defined by the annot.

        The annot is used in 2 or 3 ways.

        • It specifies the left-most position in the index where the iteration starts.
        • It specifies an end point where the iterator stops.
        • If strict is specified, the end point also specifies which annotations will be skipped while iterating.

        The starting position is computed by first finding the position whose annotation compares equal with the annot, and then advancing until reaching a position where the annotation there is not equal to the annot. If no item in the index is equal (meaning it has the same begin, the same end, and is the same type as the annot) then the iterator is positioned to the first annotation which is greater than the annot, or if there are no annotations greater than the annot, the iterator is marked invalid.

        The iterator will stop (become invalid) when

        • it runs out of items in the index going forward or backwards, or
        • while moving forward, it reaches a point where the annotation at that position has a start is beyond the annot's end position, or
        • while moving backwards, it reaches a position in front of its original starting position

        Ignoring strict and ambiguous for a moment, this is equivalent to returning annotations b such that

        • annot < b using the standard annotation comparator, and
        • annot.getEnd() >= b.getBegin(), and also bounded by the index itself.

        A strict subiterator skips annotations where annot.getEnd() < b.getEnd().

        A ambiguous = false specification produces an unambiguous iterator, which computes a subset of the annotations, going forward, such that annotations whose begin is contained within the previous returned annotation's span, are skipped.

        For annotations x,y, x < y here is to be interpreted as "x comes before y in the index", according to the rules defined in the description of this class.

        If strict = true then annotations whose end is > annot.getEnd() are skipped.

        These definitions imply that annotations b that have the same span as annot may or may not be returned by the subiterator. This is determined by the type priorities; the subiterator will only return such an annotation b if the type of annot precedes the type of b in the type priorities definition. If you have not specified the priority, or if annot and b are of the same type, then the behavior is undefined.

        For example, if you have an annotation S of type Sentence and an annotation P of type Paragraph that have the same span, and you have defined Paragraph before Sentence in your type priorities, then subiterator(P) will give you an iterator that will return S, but subiterator(S) will give you an iterator that will NOT return P. The intuition is that a Paragraph is conceptually larger than a Sentence, as defined by the type priorities.

        Specified by:
        subiterator in interface AnnotationIndex<T extends AnnotationFS>
        Parameters:
        annot - Annotation setting boundary conditions for subiterator.
        ambiguous - If set to false, resulting iterator will be unambiguous.
        strict - Controls if annotations that overlap to the right are considered in or out.
        Returns:
        A subiterator.
      • tree

        public AnnotationTree<T> tree​(T annot)
        Description copied from interface: AnnotationIndex
        Create an annotation tree with annot as root node. The tree is defined as follows: for each node in the tree, the children are the sequence of annotations that would be obtained from a strict, unambiguous subiterator of the node's annotation.
        Specified by:
        tree in interface AnnotationIndex<T extends AnnotationFS>
        Parameters:
        annot - The annotation at the root of the tree. This must be of type T or a subtype
        Returns:
        The annotation tree rooted at annot.
      • withSnapshotIterators

        public FSIndex<T> withSnapshotIterators()
        Description copied from interface: FSIndex
        Creates a shared copy of this FSIndex configured to produce snapshot iterators that don't throw ConcurrentModificationExceptions.
        Specified by:
        withSnapshotIterators in interface FSIndex<T extends AnnotationFS>
        Returns:
        a light-weight copy of this FSIndex, configured such that any iterator created using it will be a snapshot iterator - one where a snapshot is made of the state of the index at the time the iterator is created, and where subsequent modifications to the underlying index are allowed, but don't affect the iterator (which iterates over the read-only snapshot). Iterators produced with this won't throw ConcurrentModificationExceptions.