Add old() and new() functions.

Author: coreh

Diff for: Readme.md

@@ -55,6 +55,34 @@ Becomes:
 
 Converts a delta string back into a diff. This requires the original text.
 
+### diff.old(diff)
+
+Returns the old (source) text from a diff.
+
+#### Example
+
+The call:
+
+    diff.old([[0,"hi "], [-1,"joe"], [1,"sarah"], [0,", I "], [1,"dis"], [0,"like "], [-1,"cu"], [0,"p"], [1,"an"], [0,"cakes"]])
+
+Returns:
+
+    'hi joe, I like cupcakes'
+
+### diff.new(diff)
+
+Returns the new (destination) text from a diff.
+
+#### Example
+
+The call:
+
+    diff.new([[0,"hi "], [-1,"joe"], [1,"sarah"], [0,", I "], [1,"dis"], [0,"like "], [-1,"cu"], [0,"p"], [1,"an"], [0,"cakes"]])
+
+Returns:
+
+    'hi sarah, I dislike pancakes'
+
 ## License
 
 

Diff for: index.js

@@ -38,4 +38,28 @@ diff.fromDelta = function(oldText, delta) {
   return dmp.diff_fromDelta(oldText, delta);
 }
 
+/**
+ * Returns the old (source) text from a diff.
+ * @param {Array} diff
+ * @returns {String}
+ * @api public
+ */
+
+diff.old = function(diff) {
+  var dmp = new diff_match_patch();
+  return dmp.diff_text1(diff);
+}
+
+/**
+ * Returns the new (destination) text from a diff.
+ * @param {Array} diff
+ * @returns {String}
+ * @api public
+ */
+
+diff.new = function(diff) {
+  var dmp = new diff_match_patch();
+  return dmp.diff_text2(diff);
+}
+
 module.exports = diff;