Example usage for java.util LinkedList listIterator

List of usage examples for java.util LinkedList listIterator

Introduction

In this page you can find the example usage for java.util LinkedList listIterator.

Prototype

ListIterator<E> listIterator();

Source Link

Document

Returns a list iterator over the elements in this list (in proper sequence).

Usage

From source file:org.trnltk.experiment.morphology.ambiguity.DataDiffUtil.java

/**
 * Reduce the number of edits by eliminating semantically trivial equalities.
 *
 * @param diffs LinkedList of Diff objects.
 *//*  w  ww. j  a  v a 2s .co m*/
public void diff_cleanupSemantic(LinkedList<Diff<T>> diffs) {
    if (diffs.isEmpty()) {
        return;
    }
    boolean changes = false;
    Stack<Diff<T>> equalities = new Stack<Diff<T>>(); // Stack of qualities.
    List<T> lastequality = null; // Always equal to equalities.lastElement().text
    ListIterator<Diff<T>> pointer = diffs.listIterator();
    // Number of characters that changed prior to the equality.
    int length_insertions1 = 0;
    int length_deletions1 = 0;
    // Number of characters that changed after the equality.
    int length_insertions2 = 0;
    int length_deletions2 = 0;
    Diff<T> thisDiff = pointer.next();
    while (thisDiff != null) {
        if (thisDiff.operation == Operation.EQUAL) {
            // Equality found.
            equalities.push(thisDiff);
            length_insertions1 = length_insertions2;
            length_deletions1 = length_deletions2;
            length_insertions2 = 0;
            length_deletions2 = 0;
            lastequality = thisDiff.text;
        } else {
            // An insertion or deletion.
            if (thisDiff.operation == Operation.INSERT) {
                length_insertions2 += thisDiff.text.size();
            } else {
                length_deletions2 += thisDiff.text.size();
            }
            // Eliminate an equality that is smaller or equal to the edits on both
            // sides of it.
            if (lastequality != null && (lastequality.size() <= Math.max(length_insertions1, length_deletions1))
                    && (lastequality.size() <= Math.max(length_insertions2, length_deletions2))) {
                //System.out.println("Splitting: '" + lastequality + "'");
                // Walk back to offending equality.
                while (thisDiff != equalities.lastElement()) {
                    thisDiff = pointer.previous();
                }
                pointer.next();

                // Replace equality with a delete.
                pointer.set(new Diff(Operation.DELETE, lastequality));
                // Insert a corresponding an insert.
                pointer.add(new Diff(Operation.INSERT, lastequality));

                equalities.pop(); // Throw away the equality we just deleted.
                if (!equalities.empty()) {
                    // Throw away the previous equality (it needs to be reevaluated).
                    equalities.pop();
                }
                if (equalities.empty()) {
                    // There are no previous equalities, walk back to the start.
                    while (pointer.hasPrevious()) {
                        pointer.previous();
                    }
                } else {
                    // There is a safe equality we can fall back to.
                    thisDiff = equalities.lastElement();
                    while (thisDiff != pointer.previous()) {
                        // Intentionally empty loop.
                    }
                }

                length_insertions1 = 0; // Reset the counters.
                length_insertions2 = 0;
                length_deletions1 = 0;
                length_deletions2 = 0;
                lastequality = null;
                changes = true;
            }
        }
        thisDiff = pointer.hasNext() ? pointer.next() : null;
    }

    // Normalize the diff.
    if (changes) {
        diff_cleanupMerge(diffs);
    }
    diff_cleanupSemanticLossless(diffs);

    // Find any overlaps between deletions and insertions.
    // e.g: <del>abcxxx</del><ins>xxxdef</ins>
    //   -> <del>abc</del>xxx<ins>def</ins>
    // e.g: <del>xxxabc</del><ins>defxxx</ins>
    //   -> <ins>def</ins>xxx<del>abc</del>
    // Only extract an overlap if it is as big as the edit ahead or behind it.
    pointer = diffs.listIterator();
    Diff<T> prevDiff = null;
    thisDiff = null;
    if (pointer.hasNext()) {
        prevDiff = pointer.next();
        if (pointer.hasNext()) {
            thisDiff = pointer.next();
        }
    }
    while (thisDiff != null) {
        if (prevDiff.operation == Operation.DELETE && thisDiff.operation == Operation.INSERT) {
            List<T> deletion = prevDiff.text;
            List<T> insertion = thisDiff.text;
            int overlap_length1 = this.diff_commonOverlap(deletion, insertion);
            int overlap_length2 = this.diff_commonOverlap(insertion, deletion);
            if (overlap_length1 >= overlap_length2) {
                if (overlap_length1 >= deletion.size() / 2.0 || overlap_length1 >= insertion.size() / 2.0) {
                    // Overlap found. Insert an equality and trim the surrounding edits.
                    pointer.previous();
                    pointer.add(new Diff<T>(Operation.EQUAL, insertion.subList(0, overlap_length1)));
                    prevDiff.text = deletion.subList(0, deletion.size() - overlap_length1);
                    thisDiff.text = insertion.subList(overlap_length1, insertion.size());
                    // pointer.add inserts the element before the cursor, so there is
                    // no need to step past the new element.
                }
            } else {
                if (overlap_length2 >= deletion.size() / 2.0 || overlap_length2 >= insertion.size() / 2.0) {
                    // Reverse overlap found.
                    // Insert an equality and swap and trim the surrounding edits.
                    pointer.previous();
                    pointer.add(new Diff<T>(Operation.EQUAL, deletion.subList(0, overlap_length2)));
                    prevDiff.operation = Operation.INSERT;
                    prevDiff.text = insertion.subList(0, insertion.size() - overlap_length2);
                    thisDiff.operation = Operation.DELETE;
                    thisDiff.text = deletion.subList(overlap_length2, deletion.size());
                    // pointer.add inserts the element before the cursor, so there is
                    // no need to step past the new element.
                }
            }
            thisDiff = pointer.hasNext() ? pointer.next() : null;
        }
        prevDiff = thisDiff;
        thisDiff = pointer.hasNext() ? pointer.next() : null;
    }
}

From source file:org.trnltk.experiment.morphology.ambiguity.DataDiffUtil.java

/**
 * Look for single edits surrounded on both sides by equalities
 * which can be shifted sideways to align the edit to a word boundary.
 * e.g: The c<ins>at c</ins>ame. -> The <ins>cat </ins>came.
 *
 * @param diffs LinkedList of Diff objects.
 */// ww w  .j  a  v a2  s  .  c  o  m
public void diff_cleanupSemanticLossless(LinkedList<Diff<T>> diffs) {
    List<T> equality1, edit, equality2;
    List<T> commonString;
    int commonOffset;
    int score, bestScore;
    List<T> bestEquality1, bestEdit, bestEquality2;
    // Create a new iterator at the start.
    ListIterator<Diff<T>> pointer = diffs.listIterator();
    Diff<T> prevDiff = pointer.hasNext() ? pointer.next() : null;
    Diff<T> thisDiff = pointer.hasNext() ? pointer.next() : null;
    Diff<T> nextDiff = pointer.hasNext() ? pointer.next() : null;
    // Intentionally ignore the first and last element (don't need checking).
    while (nextDiff != null) {
        if (prevDiff.operation == Operation.EQUAL && nextDiff.operation == Operation.EQUAL) {
            // This is a single edit surrounded by equalities.
            equality1 = prevDiff.text;
            edit = thisDiff.text;
            equality2 = nextDiff.text;

            // First, shift the edit as far left as possible.
            commonOffset = diff_commonSuffix(equality1, edit);
            if (commonOffset != 0) {
                commonString = edit.subList(edit.size() - commonOffset, edit.size());
                equality1 = equality1.subList(0, equality1.size() - commonOffset);
                edit = ListUtils.union(commonString, edit.subList(0, edit.size() - commonOffset));
                equality2 = ListUtils.union(commonString, equality2);
            }

            // Second, step character by character right, looking for the best fit.
            bestEquality1 = equality1;
            bestEdit = edit;
            bestEquality2 = equality2;
            bestScore = diff_cleanupSemanticScore(equality1, edit) + diff_cleanupSemanticScore(edit, equality2);
            while (edit.size() != 0 && equality2.size() != 0 && edit.get(0).equals(equality2.get(0))) {
                equality1 = ListUtils.union(equality1, Arrays.asList(edit.get(0)));
                edit = ListUtils.union(edit.subList(1, edit.size()), Arrays.asList(equality2.get(0)));
                equality2 = equality2.subList(1, equality2.size());
                score = diff_cleanupSemanticScore(equality1, edit) + diff_cleanupSemanticScore(edit, equality2);
                // The >= encourages trailing rather than leading whitespace on edits.
                if (score >= bestScore) {
                    bestScore = score;
                    bestEquality1 = equality1;
                    bestEdit = edit;
                    bestEquality2 = equality2;
                }
            }

            if (!prevDiff.text.equals(bestEquality1)) {
                // We have an improvement, save it back to the diff.
                if (bestEquality1.size() != 0) {
                    prevDiff.text = bestEquality1;
                } else {
                    pointer.previous(); // Walk past nextDiff.
                    pointer.previous(); // Walk past thisDiff.
                    pointer.previous(); // Walk past prevDiff.
                    pointer.remove(); // Delete prevDiff.
                    pointer.next(); // Walk past thisDiff.
                    pointer.next(); // Walk past nextDiff.
                }
                thisDiff.text = bestEdit;
                if (bestEquality2.size() != 0) {
                    nextDiff.text = bestEquality2;
                } else {
                    pointer.remove(); // Delete nextDiff.
                    nextDiff = thisDiff;
                    thisDiff = prevDiff;
                }
            }
        }
        prevDiff = thisDiff;
        thisDiff = nextDiff;
        nextDiff = pointer.hasNext() ? pointer.next() : null;
    }
}

From source file:org.trnltk.experiment.morphology.ambiguity.DataDiffUtil.java

/**
 * Reduce the number of edits by eliminating operationally trivial equalities.
 *
 * @param diffs LinkedList of Diff objects.
 */// www  . j  a v  a 2  s  . c  o m
public void diff_cleanupEfficiency(LinkedList<Diff<T>> diffs) {
    if (diffs.isEmpty()) {
        return;
    }
    boolean changes = false;
    Stack<Diff> equalities = new Stack<Diff>(); // Stack of equalities.
    List<T> lastequality = null; // Always equal to equalities.lastElement().text
    ListIterator<Diff<T>> pointer = diffs.listIterator();
    // Is there an insertion operation before the last equality.
    boolean pre_ins = false;
    // Is there a deletion operation before the last equality.
    boolean pre_del = false;
    // Is there an insertion operation after the last equality.
    boolean post_ins = false;
    // Is there a deletion operation after the last equality.
    boolean post_del = false;
    Diff<T> thisDiff = pointer.next();
    Diff<T> safeDiff = thisDiff; // The last Diff that is known to be unsplitable.
    while (thisDiff != null) {
        if (thisDiff.operation == Operation.EQUAL) {
            // Equality found.
            if (thisDiff.text.size() < Diff_EditCost && (post_ins || post_del)) {
                // Candidate found.
                equalities.push(thisDiff);
                pre_ins = post_ins;
                pre_del = post_del;
                lastequality = thisDiff.text;
            } else {
                // Not a candidate, and can never become one.
                equalities.clear();
                lastequality = null;
                safeDiff = thisDiff;
            }
            post_ins = post_del = false;
        } else {
            // An insertion or deletion.
            if (thisDiff.operation == Operation.DELETE) {
                post_del = true;
            } else {
                post_ins = true;
            }
            /*
             * Five types to be split:
             * <ins>A</ins><del>B</del>XY<ins>C</ins><del>D</del>
             * <ins>A</ins>X<ins>C</ins><del>D</del>
             * <ins>A</ins><del>B</del>X<ins>C</ins>
             * <ins>A</del>X<ins>C</ins><del>D</del>
             * <ins>A</ins><del>B</del>X<del>C</del>
             */
            if (lastequality != null && ((pre_ins && pre_del && post_ins && post_del)
                    || ((lastequality.size() < Diff_EditCost / 2) && ((pre_ins ? 1 : 0) + (pre_del ? 1 : 0)
                            + (post_ins ? 1 : 0) + (post_del ? 1 : 0)) == 3))) {
                //System.out.println("Splitting: '" + lastequality + "'");
                // Walk back to offending equality.
                while (thisDiff != equalities.lastElement()) {
                    thisDiff = pointer.previous();
                }
                pointer.next();

                // Replace equality with a delete.
                pointer.set(new Diff(Operation.DELETE, lastequality));
                // Insert a corresponding an insert.
                pointer.add(thisDiff = new Diff(Operation.INSERT, lastequality));

                equalities.pop(); // Throw away the equality we just deleted.
                lastequality = null;
                if (pre_ins && pre_del) {
                    // No changes made which could affect previous entry, keep going.
                    post_ins = post_del = true;
                    equalities.clear();
                    safeDiff = thisDiff;
                } else {
                    if (!equalities.empty()) {
                        // Throw away the previous equality (it needs to be reevaluated).
                        equalities.pop();
                    }
                    if (equalities.empty()) {
                        // There are no previous questionable equalities,
                        // walk back to the last known safe diff.
                        thisDiff = safeDiff;
                    } else {
                        // There is an equality we can fall back to.
                        thisDiff = equalities.lastElement();
                    }
                    while (thisDiff != pointer.previous()) {
                        // Intentionally empty loop.
                    }
                    post_ins = post_del = false;
                }

                changes = true;
            }
        }
        thisDiff = pointer.hasNext() ? pointer.next() : null;
    }

    if (changes) {
        diff_cleanupMerge(diffs);
    }
}

From source file:org.trnltk.experiment.morphology.ambiguity.DataDiffUtil.java

/**
 * Reorder and merge like edit sections.  Merge equalities.
 * Any edit section can move as long as it doesn't cross an equality.
 *
 * @param diffs LinkedList of Diff objects.
 *//*from www  .ja  va  2s. c  o  m*/
public void diff_cleanupMerge(LinkedList<Diff<T>> diffs) {
    diffs.add(new Diff<T>(Operation.EQUAL, new ArrayList<T>())); // Add a dummy entry at the end.
    ListIterator<Diff<T>> pointer = diffs.listIterator();
    int count_delete = 0;
    int count_insert = 0;
    List<T> text_delete = new ArrayList<T>();
    List<T> text_insert = new ArrayList<T>();
    Diff thisDiff = pointer.next();
    Diff prevEqual = null;
    int commonlength;
    while (thisDiff != null) {
        switch (thisDiff.operation) {
        case INSERT:
            count_insert++;
            text_insert = ListUtils.union(text_insert, thisDiff.text);
            prevEqual = null;
            break;
        case DELETE:
            count_delete++;
            text_delete = ListUtils.union(text_delete, thisDiff.text);
            prevEqual = null;
            break;
        case EQUAL:
            if (count_delete + count_insert > 1) {
                boolean both_types = count_delete != 0 && count_insert != 0;
                // Delete the offending records.
                pointer.previous(); // Reverse direction.
                while (count_delete-- > 0) {
                    pointer.previous();
                    pointer.remove();
                }
                while (count_insert-- > 0) {
                    pointer.previous();
                    pointer.remove();
                }
                if (both_types) {
                    // Factor out any common prefixies.
                    commonlength = diff_commonPrefix(text_insert, text_delete);
                    if (commonlength != 0) {
                        if (pointer.hasPrevious()) {
                            thisDiff = pointer.previous();
                            assert thisDiff.operation == Operation.EQUAL : "Previous diff should have been an equality.";
                            thisDiff.text = ListUtils.union(thisDiff.text,
                                    text_insert.subList(0, commonlength));
                            pointer.next();
                        } else {
                            pointer.add(new Diff(Operation.EQUAL, text_insert.subList(0, commonlength)));
                        }
                        text_insert = text_insert.subList(commonlength, text_insert.size());
                        text_delete = text_delete.subList(commonlength, text_delete.size());
                    }
                    // Factor out any common suffixies.
                    commonlength = diff_commonSuffix(text_insert, text_delete);
                    if (commonlength != 0) {
                        thisDiff = pointer.next();
                        thisDiff.text = ListUtils.union(
                                text_insert.subList(text_insert.size() - commonlength, text_insert.size()),
                                thisDiff.text);
                        text_insert = text_insert.subList(0, text_insert.size() - commonlength);
                        text_delete = text_delete.subList(0, text_delete.size() - commonlength);
                        pointer.previous();
                    }
                }
                // Insert the merged records.
                if (text_delete.size() != 0) {
                    pointer.add(new Diff(Operation.DELETE, text_delete));
                }
                if (text_insert.size() != 0) {
                    pointer.add(new Diff(Operation.INSERT, text_insert));
                }
                // Step forward to the equality.
                thisDiff = pointer.hasNext() ? pointer.next() : null;
            } else if (prevEqual != null) {
                // Merge this equality with the previous one.
                prevEqual.text = ListUtils.union(prevEqual.text, thisDiff.text);
                pointer.remove();
                thisDiff = pointer.previous();
                pointer.next(); // Forward direction
            }
            count_insert = 0;
            count_delete = 0;
            text_delete = new ArrayList<T>();
            text_insert = new ArrayList<T>();
            prevEqual = thisDiff;
            break;
        }
        thisDiff = pointer.hasNext() ? pointer.next() : null;
    }
    if (diffs.getLast().text.size() == 0) {
        diffs.removeLast(); // Remove the dummy entry at the end.
    }

    /*
     * Second pass: look for single edits surrounded on both sides by equalities
     * which can be shifted sideways to eliminate an equality.
     * e.g: A<ins>BA</ins>C -> <ins>AB</ins>AC
     */
    boolean changes = false;
    // Create a new iterator at the start.
    // (As opposed to walking the current one back.)
    pointer = diffs.listIterator();
    Diff<T> prevDiff = pointer.hasNext() ? pointer.next() : null;
    thisDiff = pointer.hasNext() ? pointer.next() : null;
    Diff nextDiff = pointer.hasNext() ? pointer.next() : null;
    // Intentionally ignore the first and last element (don't need checking).
    while (nextDiff != null) {
        if (prevDiff.operation == Operation.EQUAL && nextDiff.operation == Operation.EQUAL) {
            // This is a single edit surrounded by equalities.
            if (endsWith(thisDiff.text, prevDiff.text)) {
                // Shift the edit over the previous equality.
                thisDiff.text = ListUtils.union(prevDiff.text,
                        thisDiff.text.subList(0, thisDiff.text.size() - prevDiff.text.size()));
                nextDiff.text = ListUtils.union(prevDiff.text, nextDiff.text);
                pointer.previous(); // Walk past nextDiff.
                pointer.previous(); // Walk past thisDiff.
                pointer.previous(); // Walk past prevDiff.
                pointer.remove(); // Delete prevDiff.
                pointer.next(); // Walk past thisDiff.
                thisDiff = pointer.next(); // Walk past nextDiff.
                nextDiff = pointer.hasNext() ? pointer.next() : null;
                changes = true;
            } else if (startsWith(thisDiff.text, nextDiff.text)) {
                // Shift the edit over the next equality.
                prevDiff.text = ListUtils.union(prevDiff.text, nextDiff.text);
                thisDiff.text = ListUtils.union(
                        thisDiff.text.subList(nextDiff.text.size(), thisDiff.text.size()), nextDiff.text);
                pointer.remove(); // Delete nextDiff.
                nextDiff = pointer.hasNext() ? pointer.next() : null;
                changes = true;
            }
        }
        prevDiff = thisDiff;
        thisDiff = nextDiff;
        nextDiff = pointer.hasNext() ? pointer.next() : null;
    }
    // If shifts were made, the diff needs reordering and another shift sweep.
    if (changes) {
        diff_cleanupMerge(diffs);
    }
}

From source file:ru.runa.wfe.extension.orgfunction.DemoSubordinateRecursive.java

/**
 * @param list/*  w w w  .ja v a  2 s .  co  m*/
 * @param subordinatesList
 * @param demoChiefFunction
 * @throws OrgFunctionException
 */
private void findIndirectSubordinates(LinkedList<Actor> list, LinkedList<Actor> subordinatesList,
        DemoChiefFunction demoChiefFunction) throws OrgFunctionException {
    int flag = -1;
    while (flag != 0) {
        LinkedList<Actor> newGeneratedSubordinates = new LinkedList<Actor>();
        for (ListIterator<Actor> iter = subordinatesList.listIterator(); iter.hasNext();) {
            findDirectSubordinates(list, newGeneratedSubordinates, iter.next(), demoChiefFunction);
        }
        flag = addNotContainedElements(subordinatesList, newGeneratedSubordinates);
    }
}

From source file:ru.runa.wfe.extension.orgfunction.DemoSubordinateRecursive.java

/**
 * @param subordinatesList/* w ww  .  j a v a2 s  .c o m*/
 * @param flag
 * @param newSubordinates
 * @return
 */
private int addNotContainedElements(LinkedList<Actor> subordinatesList,
        LinkedList<Actor> newGeneratedSubordinates) {
    int flag = 0;
    for (ListIterator<Actor> iter = newGeneratedSubordinates.listIterator(); iter.hasNext();) {
        Actor acurr = iter.next();
        if (!subordinatesList.contains(acurr)) {
            subordinatesList.add(acurr);
            flag = -1;
        }
    }

    return flag;
}