feat: update repo and dependencies (#1) #6
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upgrade gopkg.in/yaml.v2
Use common cache of line contents between two texts in `DiffLinesToChars` to get line diffs correctly. In some cases, line diffs cannot be retrieved correctly in the standard way (https://github.com/google/diff-match-patch/wiki/Line-or-Word-Diffs#line-mode). In the below case, we failed to get line diffs correctly before this fix. ```go:main.go package main import ( "fmt" "github.com/sergi/go-diff/diffmatchpatch" ) const ( text1 = `hoge: step11: - arrayitem1 - arrayitem2 step12: step21: hoge step22: -93 fuga: flatitem ` text2 = `hoge: step11: - arrayitem4 - arrayitem2 - arrayitem3 step12: step21: hoge step22: -92 fuga: flatitem ` ) func main() { dmp := diffmatchpatch.New() a, b, c := dmp.DiffLinesToChars(text1, text2) diffs := dmp.DiffMain(a, b, false) diffs = dmp.DiffCharsToLines(diffs, c) // diffs = dmp.DiffCleanupSemantic(diffs) fmt.Println(diffs) } ``` ```text:output [{Insert hoge: step11: hoge: } {Equal hoge: } {Insert hoge: } {Equal step11: } {Insert hoge: } {Equal - arrayitem1 } {Insert hoge: } {Equal - arrayitem2 } {Insert hoge: } {Equal step12: } {Insert hoge: } {Equal step21: hoge } {Insert hoge: } {Equal step22: -93 } {Delete fuga: flatitem }] ``` Note: This fix corresponds to a javascript implementation. (ref: https://github.com/google/diff-match-patch/blob/62f2e689f498f9c92dbc588c58750addec9b1654/javascript/diff_match_patch_uncompressed.js#L466)
Use common lineHash to share indice between text1 and text2 for correct line diffs
Current implementation produces wrong result because it calls `DiffMain` on the following 2 arguments: * `1,2,3,4,5,6,7,8,9,10` * `1,2,3,4,5,6,7,8,9,11` This numbers represent indices into the lines array. The algorithm finds that equal part of those strings is `1,2,3,4,5,6,7,8,9,1` and which is followed by `Delete 0` and `Insert `1`.
[The suggested approach](https://github.com/google/diff-match-patch/wiki/Line-or-Word-Diffs#line-mode ) for doing line level diffing is the following set of steps: 1. `ti1, ti2, linesIdx = DiffLinesToChars(t1, t2)` 2. `diffs = DiffMain(ti1, ti2)` 3. `DiffCharsToLines(diff, linesIdx)` The original implementation in `google/diff-match-patch` uses unicode codepoints for storing indices in `ti1` and `ti2` joined by an empty string. Current implementation in this repo stores them as integers joined by a comma. While this implementation makes `ti1` and `ti2` more readable, it introduces bugs when trying to rely on it when doing line level diffing with `DiffMain`. The root cause of the issue is that an integer line index might span more than one character/rune, and `DiffMain` can assume that two different lines having the same index prefix match partially. For example, indices 123 and 129 will have partial match `12`. In that example, the diff will show lines 3 and 9 which is not correct. A simple failing test case demonstrating this issue is available at `TestDiffPartialLineIndex`. In this PR I am adjusting the algorithm to use the same approach as in [diff-match-patch](https://github.com/google/diff-match-patch/blob/62f2e689f498f9c92dbc588c58750addec9b1654/javascript/diff_match_patch_uncompressed.js#L508-L510 ) by storing each line index as a rune. While a rune in Golang is a type alias to uint32, not every uint32 can be a valid rune. During string to rune slice conversion invalid runes will be replaced with `utf.RuneError`. The integer to rune generation logic is based on the table in https://en.wikipedia.org/wiki/UTF-8#Encoding The first 127 lines will work the fastest as they are represented as a single bytes. Higher numbers are represented as 2-4 bytes. In addition to that, the range `U+D800 - U+DFFF` contains [invalid codepoints](https://en.wikipedia.org/wiki/UTF-8#Invalid_sequences_and_error_handling). and all codepoints higher or equal to `0xD800` are incremented by `0xDFFF - 0xD800`. The maximum representable integer using this approach is 1'112'060. This improves on Javascript implementation which currently [bails out](https://github.com/google/diff-match-patch/blob/62f2e689f498f9c92dbc588c58750addec9b1654/javascript/diff_match_patch_uncompressed.js#L503-L505 ) when files have more than 65535 lines.
Fix line diff by using rune index without a separator
…red_text Fix colored display for diffs with newlines
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Release new forked version with no security issue