Add ability to restore sequence after differ

src/differ.rs

@@ -181,6 +181,28 @@ impl Differ{
         res
     }
 
+    pub fn restore(delta: &Vec<String>, which: usize) -> Vec<String> {
+        if !(which == 1 || which == 2) {
+            panic!("Second parameter must be 1 or 2");
+        }
+        let mut res = Vec::new();
+        let mut tag = String::new();
+        if which == 1 {
+            tag = "- ".to_string();
+        } else {
+            tag = "+ ".to_string();
+        }
+        let prefixes = vec![tag, "  ".to_string()];
+        for line in delta {
+            for prefix in &prefixes {
+                if line.starts_with(prefix) {
+                    res.push( line.split_at(2).1.to_string() );
+                }
+            }
+        }
+        res
+    }
+
 }
 
 #[test]

src/lib.rs

@@ -124,4 +124,4 @@ pub fn context_diff<T: Sequence>(first_sequence: &T, second_sequence: &T, from_f
 		}
 	}
 	res
-}
+}

tests/test.rs

@@ -102,6 +102,16 @@ fn test_differ_compare() {
     assert_eq!(result, "- one\n?  ^\n+ ore\n?  ^\n- two\n- three\n?  -\n+ tree\n+ emu\n");
 }
 
+#[test]
+fn test_differ_restore() {
+    let first_text = vec!["one\n", "two\n", "three\n"];
+    let second_text = vec!["ore\n", "tree\n", "emu\n"];
+    let differ = Differ::new();
+    let diff = differ.compare(&first_text, &second_text);
+    assert_eq!(first_text, Differ::restore(&diff, 1));
+    assert_eq!(second_text, Differ::restore(&diff, 2));
+}
+
 #[test]
 fn test_unified_diff() {
     let first_text = "one two three four".split(" ").collect::<Vec<&str>>();