Fix analyzer warnings in the YAML package.

pkg/yaml/lib/src/parser.dart

Index: pkg/yaml/lib/src/parser.dart
diff --git a/pkg/yaml/lib/src/parser.dart b/pkg/yaml/lib/src/parser.dart
index 2616038ee175b0b25020af36f9b6789618742aa9..fcf1402e7db0665d0d24b60734cde4e841709971 100644
--- a/pkg/yaml/lib/src/parser.dart
+++ b/pkg/yaml/lib/src/parser.dart
@@ -1106,13 +1106,16 @@ class Parser {
   // 136
   int inFlow(int ctx) {
     switch (ctx) {
-    case FLOW_OUT:
-    case FLOW_IN:
-      return FLOW_IN;
-    case BLOCK_KEY:
-    case FLOW_KEY:
-      return FLOW_KEY;
+      case FLOW_OUT:
+      case FLOW_IN:
+        return FLOW_IN;
+      case BLOCK_KEY:
+      case FLOW_KEY:
+        return FLOW_KEY;
     }
+    assert(false);
+    // Remove this return when issue 18730 is fixed.
+    return null;

[Bob Nystrom, 2014/05/08 21:01:04]

Most other code I've seen uses:

throw "unreachable";

for this.

[nweiz, 2014/05/08 21:18:18]

Done.

   }
 
   // 137
@@ -1434,6 +1437,9 @@ class Parser {
     case CHOMPING_KEEP:
       return b_asLineFeed();
     }
+    assert(false);
+    // Remove this return when issue 18730 is fixed.
+    return null;
   }
 
   // 166