my fork of dmp
| -rw-r--r-- | src/dmp.rs | 59 |
1 files changed, 59 insertions, 0 deletions
@@ -2845,6 +2845,7 @@ impl DiffMatchPatch { pub fn new() -> Self { Self::default() } + /// Find the differences between two texts (old and new). Simplifies the problem by stripping any common prefix or suffix off the texts before diffing. /// /// Returns: @@ -3041,6 +3042,64 @@ impl DiffMatchPatch { // Ok(html) } + /// Given a location in text1, compute and return the equivalent location in text2. + /// e.g. "The cat" -> "The big cat", 1->1, 4->8 + /// # Example + /// ``` + /// # use diff_match_patch_rs::{DiffMatchPatch, Error, Efficient}; + /// # fn main() -> Result<(), Error> { + /// let dmp = DiffMatchPatch::new(); + /// let diffs1 = dmp.diff_main::<Efficient>("The cat", "The big cat").unwrap(); + /// assert_eq!(DiffMatchPatch::diff_x_index(&diffs1, 1), 1); + /// assert_eq!(DiffMatchPatch::diff_x_index(&diffs1, 4), 8); + /// let diffs2 = dmp.diff_main::<Efficient>("The big cat", "The cat").unwrap(); + /// assert_eq!(DiffMatchPatch::diff_x_index(&diffs2, 1), 1); + /// assert_eq!(DiffMatchPatch::diff_x_index(&diffs2, 9), 5); + /// assert_eq!(DiffMatchPatch::diff_x_index(&diffs2, 6), 4); + /// # Ok(()) + /// # } + /// ``` + pub fn diff_x_index<D: DType>(diffs: &[Diff<D>], loc: usize) -> usize { + let mut chars1 = 0; + let mut chars2 = 0; + let mut last_chars1 = 0; + let mut last_chars2 = 0; + + for diff in diffs { + match diff.op() { + Ops::Delete => { + chars1 += diff.data().len(); + } + Ops::Insert => { + chars2 += diff.data().len(); + } + Ops::Equal => { + chars1 += diff.data().len(); + chars2 += diff.data().len(); + } + } + + if chars1 > loc { + // Overshot the location + match diff.op() { + Ops::Delete => { + // The location was deleted + return last_chars2; + } + _ => { + // The location was changed + return last_chars2 + (loc - last_chars1); + } + } + } + + last_chars1 = chars1; + last_chars2 = chars2; + } + + chars2 + } + /// Given a text to search, a pattern to search for and an expected location in the text near which to find the pattern, return the location which matches closest. /// The function will search for the best match based on both the number of character errors between the pattern and the potential match, /// as well as the distance between the expected location and the potential match. |