Basic diffing

1 files changed, 26 insertions, 0 deletions

diff --git a/src/diff.rs b/src/diff.rs
new file mode 100644
index 0000000..0d11400
--- /dev/null
+++ b/src/diff.rs
@@ -0,0 +1,26 @@
+use std::ops::Range;
+
+use imara_diff::{Algorithm, Diff, Hunk, InternedInput};
+
+pub enum DiffSpan {
+	Insertion(Range<u32>),
+	Deletion(Range<u32>),
+}
+
+pub fn diff(before: &[u8], after: &[u8]) -> Vec<DiffSpan> {
+	let input = InternedInput::new(before, after);
+	let diff = Diff::compute(Algorithm::Histogram, &input);
+
+	let hunks: Vec<Hunk> = diff.hunks().collect();
+	let mut spans = Vec::with_capacity(hunks.len());
+	for hunk in hunks {
+		if !hunk.before.is_empty() {
+			spans.push(DiffSpan::Deletion(hunk.before));
+		}
+		if !hunk.after.is_empty() {
+			spans.push(DiffSpan::Insertion(hunk.after));
+		}
+	}
+
+	spans
+}