Adding a simple console based diff

Author: adam-singer

bin/diff.dart

@@ -1,3 +1,33 @@
-void main() {
-  print("Hello, World!");
+import "dart:io";
+
+import "package:diff/diff.dart";
+
+void main(List<String> args) {
+  if (args.length != 3) {
+    print("diff.dart [ours] [base] [theirs]");
+    return;
+  }
+
+  String filename1 = args[0]; // ours
+  String filename2 = args[1]; // base
+  String filename3 = args[2]; // theirs
+
+  File file1 = new File(filename1);
+  String file1Contents = file1.readAsStringSync();
+
+  File file2 = new File(filename2);
+  String file2Contents = file2.readAsStringSync();
+
+  File file3 = new File(filename3);
+  String file3Contents = file3.readAsStringSync();
+
+  Diff3DigResult diff3DigResult = diff3_dig(file1Contents, file2Contents,
+      file3Contents);
+
+  if (diff3DigResult.Conflict) {
+    print("diff3_dig: $filename1, $filename2, $filename3");
+    print(diff3DigResult.Text.join("\n"));
+  } else {
+    print("No conflicts found with $filename1, $filename2, $filename3");
+  }
 }