Package com.composum.ai.aem.core.impl.autotranslate

Class DiffMatchPatch

  • public class DiffMatchPatch
extends Object
    Class containing the diff, match and patch methods. Also contains the behaviour settings.

    • Field Detail

      • Diff_Timeout

        public float Diff_Timeout
        Number of seconds to map a diff before giving up (0 for infinity).

      • Diff_EditCost

        public short Diff_EditCost
        Cost of an empty edit operation in terms of edit characters.

      • Match_Threshold

        public float Match_Threshold
        At what point is no match declared (0.0 = perfection, 1.0 = very loose).

      • Match_Distance

        public int Match_Distance
        How far to search for a match (0 = exact location, 1000+ = broad match). A match this many characters away from the expected location will add 1.0 to the score (0.0 is a perfect match).

      • Patch_DeleteThreshold

        public float Patch_DeleteThreshold
        When deleting a large block of text (over ~64 characters), how close do the contents have to be to match the expected contents. (0.0 = perfection, 1.0 = very loose). Note that Match_Threshold controls how closely the end points of a delete need to match.

      • Patch_Margin

        public short Patch_Margin
        Chunk size for context length.

    • Constructor Detail

      • DiffMatchPatch

        public DiffMatchPatch()

    • Method Detail

      • diff_main

        public LinkedList<DiffMatchPatch.Diff> diff_main​(String text1,
                                                 String text2)
        Find the differences between two texts. Run a faster, slightly less optimal diff. This method allows the 'checklines' of diff_main() to be optional. Most of the time checklines is wanted, so default to true.
        Parameters:
        text1 - Old string to be diffed.
        text2 - New string to be diffed.
        Returns:
        Linked List of Diff objects.

      • diff_main

        public LinkedList<DiffMatchPatch.Diff> diff_main​(String text1,
                                                 String text2,
                                                 boolean checklines)
        Find the differences between two texts.
        Parameters:
        text1 - Old string to be diffed.
        text2 - New string to be diffed.
        checklines - Speedup flag. If false, then don't run a line-level diff first to identify the changed areas. If true, then run a faster slightly less optimal diff.
        Returns:
        Linked List of Diff objects.

      • diff_bisect

        protected LinkedList<DiffMatchPatch.Diff> diff_bisect​(String text1,
                                                      String text2,
                                                      long deadline)
        Find the 'middle snake' of a diff, split the problem in two and return the recursively constructed diff. See Myers 1986 paper: An O(ND) Difference Algorithm and Its Variations.
        Parameters:
        text1 - Old string to be diffed.
        text2 - New string to be diffed.
        deadline - Time at which to bail if not yet complete.
        Returns:
        LinkedList of Diff objects.

      • diff_linesToChars

        protected DiffMatchPatch.LinesToCharsResult diff_linesToChars​(String text1,
                                                              String text2)
        Split two texts into a list of strings. Reduce the texts to a string of hashes where each Unicode character represents one line.
        Parameters:
        text1 - First string.
        text2 - Second string.
        Returns:
        An object containing the encoded text1, the encoded text2 and the List of unique strings. The zeroth element of the List of unique strings is intentionally blank.

      • diff_charsToLines

        protected void diff_charsToLines​(List<DiffMatchPatch.Diff> diffs,
                                 List<String> lineArray)
        Rehydrate the text in a diff from a string of line hashes to real lines of text.
        Parameters:
        diffs - List of Diff objects.
        lineArray - List of unique strings.

      • diff_commonPrefix

        public int diff_commonPrefix​(String text1,
                             String text2)
        Determine the common prefix of two strings
        Parameters:
        text1 - First string.
        text2 - Second string.
        Returns:
        The number of characters common to the start of each string.

      • diff_commonSuffix

        public int diff_commonSuffix​(String text1,
                             String text2)
        Determine the common suffix of two strings
        Parameters:
        text1 - First string.
        text2 - Second string.
        Returns:
        The number of characters common to the end of each string.

      • diff_commonOverlap

        protected int diff_commonOverlap​(String text1,
                                 String text2)
        Determine if the suffix of one string is the prefix of another.
        Parameters:
        text1 - First string.
        text2 - Second string.
        Returns:
        The number of characters common to the end of the first string and the start of the second string.

      • diff_halfMatch

        protected String[] diff_halfMatch​(String text1,
                                  String text2)
        Do the two texts share a substring which is at least half the length of the longer text? This speedup can produce non-minimal diffs.
        Parameters:
        text1 - First string.
        text2 - Second string.
        Returns:
        Five element String array, containing the prefix of text1, the suffix of text1, the prefix of text2, the suffix of text2 and the common middle. Or null if there was no match.

      • diff_cleanupSemantic

        public void diff_cleanupSemantic​(LinkedList<DiffMatchPatch.Diff> diffs)
        Reduce the number of edits by eliminating semantically trivial equalities.
        Parameters:
        diffs - LinkedList of Diff objects.

      • diff_cleanupSemanticLossless

        public void diff_cleanupSemanticLossless​(LinkedList<DiffMatchPatch.Diff> diffs)
        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 cat came. -> The cat came.
        Parameters:
        diffs - LinkedList of Diff objects.

      • diff_cleanupEfficiency

        public void diff_cleanupEfficiency​(LinkedList<DiffMatchPatch.Diff> diffs)
        Reduce the number of edits by eliminating operationally trivial equalities.
        Parameters:
        diffs - LinkedList of Diff objects.

      • diff_cleanupMerge

        public void diff_cleanupMerge​(LinkedList<DiffMatchPatch.Diff> diffs)
        Reorder and merge like edit sections. Merge equalities. Any edit section can move as long as it doesn't cross an equality.
        Parameters:
        diffs - LinkedList of Diff objects.

      • diff_xIndex

        public int diff_xIndex​(List<DiffMatchPatch.Diff> diffs,
                       int loc)
        loc is a location in text1, compute and return the equivalent location in text2. e.g. "The cat" vs "The big cat", 1->1, 5->8
        Parameters:
        diffs - List of Diff objects.
        loc - Location within text1.
        Returns:
        Location within text2.

      • diff_prettyHtml

        public String diff_prettyHtml​(List<DiffMatchPatch.Diff> diffs)
        Convert a Diff list into a pretty HTML report.
        Parameters:
        diffs - List of Diff objects.
        Returns:
        HTML representation.

      • diff_text1

        public String diff_text1​(List<DiffMatchPatch.Diff> diffs)
        Compute and return the source text (all equalities and deletions).
        Parameters:
        diffs - List of Diff objects.
        Returns:
        Source text.

      • diff_text2

        public String diff_text2​(List<DiffMatchPatch.Diff> diffs)
        Compute and return the destination text (all equalities and insertions).
        Parameters:
        diffs - List of Diff objects.
        Returns:
        Destination text.

      • diff_levenshtein

        public int diff_levenshtein​(List<DiffMatchPatch.Diff> diffs)
        Compute the Levenshtein distance; the number of inserted, deleted or substituted characters.
        Parameters:
        diffs - List of Diff objects.
        Returns:
        Number of changes.

      • diff_toDelta

        public String diff_toDelta​(List<DiffMatchPatch.Diff> diffs)
        Crush the diff into an encoded string which describes the operations required to transform text1 into text2. E.g. =3\t-2\t+ing -> Keep 3 chars, delete 2 chars, insert 'ing'. Operations are tab-separated. Inserted text is escaped using %xx notation.
        Parameters:
        diffs - List of Diff objects.
        Returns:
        Delta text.

      • diff_fromDelta

        public LinkedList<DiffMatchPatch.Diff> diff_fromDelta​(String text1,
                                                      String delta)
                                               throws IllegalArgumentException
        Given the original text1, and an encoded string which describes the operations required to transform text1 into text2, compute the full diff.
        Parameters:
        text1 - Source string for the diff.
        delta - Delta text.
        Returns:
        Array of Diff objects or null if invalid.
        Throws:
        IllegalArgumentException - If invalid input.

      • match_main

        public int match_main​(String text,
                      String pattern,
                      int loc)
        Locate the best instance of 'pattern' in 'text' near 'loc'. Returns -1 if no match found.
        Parameters:
        text - The text to search.
        pattern - The pattern to search for.
        loc - The location to search around.
        Returns:
        Best match index or -1.

      • match_bitap

        protected int match_bitap​(String text,
                          String pattern,
                          int loc)
        Locate the best instance of 'pattern' in 'text' near 'loc' using the Bitap algorithm. Returns -1 if no match found.
        Parameters:
        text - The text to search.
        pattern - The pattern to search for.
        loc - The location to search around.
        Returns:
        Best match index or -1.

      • match_alphabet

        protected Map<Character,​Integer> match_alphabet​(String pattern)
        Initialise the alphabet for the Bitap algorithm.
        Parameters:
        pattern - The text to encode.
        Returns:
        Hash of character locations.

      • patch_addContext

        protected void patch_addContext​(DiffMatchPatch.Patch patch,
                                String text)
        Increase the context until it is unique, but don't let the pattern expand beyond Match_MaxBits.
        Parameters:
        patch - The patch to grow.
        text - Source text.

      • patch_make

        public LinkedList<DiffMatchPatch.Patch> patch_make​(String text1,
                                                   String text2)
        Compute a list of patches to turn text1 into text2. A set of diffs will be computed.
        Parameters:
        text1 - Old text.
        text2 - New text.
        Returns:
        LinkedList of Patch objects.

      • patch_make

        public LinkedList<DiffMatchPatch.Patch> patch_make​(LinkedList<DiffMatchPatch.Diff> diffs)
        Compute a list of patches to turn text1 into text2. text1 will be derived from the provided diffs.
        Parameters:
        diffs - Array of Diff objects for text1 to text2.
        Returns:
        LinkedList of Patch objects.

      • patch_make

        @Deprecated
public LinkedList<DiffMatchPatch.Patch> patch_make​(String text1,
                                                   String text2,
                                                   LinkedList<DiffMatchPatch.Diff> diffs)
        Deprecated.
        Prefer patch_make(String text1, LinkedList diffs).
        Compute a list of patches to turn text1 into text2. text2 is ignored, diffs are the delta between text1 and text2.
        Parameters:
        text1 - Old text
        text2 - Ignored.
        diffs - Array of Diff objects for text1 to text2.
        Returns:
        LinkedList of Patch objects.

      • patch_make

        public LinkedList<DiffMatchPatch.Patch> patch_make​(String text1,
                                                   LinkedList<DiffMatchPatch.Diff> diffs)
        Compute a list of patches to turn text1 into text2. text2 is not provided, diffs are the delta between text1 and text2.
        Parameters:
        text1 - Old text.
        diffs - Array of Diff objects for text1 to text2.
        Returns:
        LinkedList of Patch objects.

      • patch_apply

        public Object[] patch_apply​(LinkedList<DiffMatchPatch.Patch> patches,
                            String text)
        Merge a set of patches onto the text. Return a patched text, as well as an array of true/false values indicating which patches were applied.
        Parameters:
        patches - Array of Patch objects
        text - Old text.
        Returns:
        Two element Object array, containing the new text and an array of boolean values.

      • patch_addPadding

        public String patch_addPadding​(LinkedList<DiffMatchPatch.Patch> patches)
        Add some padding on text start and end so that edges can match something. Intended to be called only from within patch_apply.
        Parameters:
        patches - Array of Patch objects.
        Returns:
        The padding string added to each side.

      • patch_splitMax

        public void patch_splitMax​(LinkedList<DiffMatchPatch.Patch> patches)
        Look through the patches and break up any which are longer than the maximum limit of the match algorithm. Intended to be called only from within patch_apply.
        Parameters:
        patches - LinkedList of Patch objects.

      • patch_toText

        public String patch_toText​(List<DiffMatchPatch.Patch> patches)
        Take a list of patches and return a textual representation.
        Parameters:
        patches - List of Patch objects.
        Returns:
        Text representation of patches.