From ab2d8ae3f38fc6ebedb58ad0068c29a55b642fe8 Mon Sep 17 00:00:00 2001
From: Natalie Weizenbaum <nweiz@google.com>
Date: Thu, 28 Jul 2016 17:40:52 -0700
Subject: [PATCH] unify complex

---
 lib/src/extender.dart | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/lib/src/extender.dart b/lib/src/extender.dart
index 6f761eec..4f4fdafa 100644
--- a/lib/src/extender.dart
+++ b/lib/src/extender.dart
@@ -186,8 +186,8 @@ class Extender {
 
       var unified = _unifyComplex(group1, group2);
       if (unified == null) return null;
-      if (unified.members.length > 1) return null;
-      return unified.members.first.members;
+      if (unified.length > 1) return null;
+      return unified.first;
     });
 
     var choices = [[initialCombinator]];
@@ -519,6 +519,24 @@ class Extender {
     return result;
   }
 
+  List<List<ComplexSelectorComponent> _unifyComplex(
+      List<SimpleSelector> complex1, List<SimpleSelector> complex2) {
+    var base1 = complex1.members.last;
+    var base2 = complex2.members.last;
+    if (base1 is CompoundSelector && base2 is CompoundSelector) {
+      var unified = _unifyCompound(base2.components, base1.components);
+      if (unified == null) return null;
+
+      return weave([
+        base1.components.take(base1.components.length - 1).toList(),
+        base2.components.take(base2.components.length - 1).toList()
+          ..add(unified)
+      ]);
+    } else {
+      return null;
+    }
+  }
+
   CompoundSelector _unifyCompound(List<SimpleSelector> compound1,
       List<SimpleSelector> compound2) {
     var result = compound2;