Updates and improvements to comments

plans/changes_src.go

@@ -157,7 +157,11 @@ type ChangeSrc struct {
 	// storage.
 	Before, After DynamicValue
 
-	// Marked Paths
+	// BeforeValMarks and AfterValMarks are stored path+mark combinations
+	// that might be discovered when encoding a change. Marks are removed
+	// to enable encoding (marked values cannot be marshalled), and so storing
+	// the path+mark combinations allow us to re-mark the value later
+	// when, for example, displaying the diff to the UI.
 	BeforeValMarks, AfterValMarks []cty.PathValueMarks
 }
 

terraform/eval_diff.go

@@ -148,8 +148,7 @@ func (n *EvalDiff) Eval(ctx EvalContext) (interface{}, error) {
 	var unmarkedPaths []cty.PathValueMarks
 	if configVal.ContainsMarked() {
 		// store the marked values so we can re-mark them later after
-		// we've sent things over the wire. Right now this stores
-		// one path for proof of concept, but we should store multiple
+		// we've sent things over the wire.
 		unmarkedConfigVal, unmarkedPaths = configVal.UnmarkDeepWithPaths()
 	}