From a072d6d6e7b62be6eaac5c2898eb79656d329989 Mon Sep 17 00:00:00 2001
From: Vincent Batts <vbatts@hashbangbash.com>
Date: Mon, 13 Aug 2018 23:09:49 -0400
Subject: [PATCH] WIP

---
 check.go   |  6 +++---
 compare.go | 16 ++++++++++------
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/check.go b/check.go
index 29e05e3..0e63e5a 100644
--- a/check.go
+++ b/check.go
@@ -5,18 +5,18 @@ package mtree
 // If keywords is nil, the check all present in the DirectoryHierarchy
 //
 // This is equivalent to creating a new DirectoryHierarchy with Walk(root, nil,
-// keywords, fs) and then doing a Compare(dh, newDh, keywords).
+// keywords, fs) and then doing a Compare(dh, curDh, keywords).
 func Check(root string, dh *DirectoryHierarchy, keywords []Keyword, fs FsEval) ([]InodeDelta, error) {
 	if keywords == nil {
 		keywords = dh.UsedKeywords()
 	}
 
-	newDh, err := Walk(root, nil, keywords, fs)
+	curDh, err := Walk(root, nil, keywords, fs)
 	if err != nil {
 		return nil, err
 	}
 
-	return Compare(dh, newDh, keywords)
+	return Compare(dh, curDh, keywords)
 }
 
 // TarCheck is the tar equivalent of checking a file hierarchy spec against a
diff --git a/compare.go b/compare.go
index 5394832..5549e24 100644
--- a/compare.go
+++ b/compare.go
@@ -325,13 +325,17 @@ func compareEntry(oldEntry, newEntry Entry) ([]KeyDelta, error) {
 // missing entries and the like). A missing or extra key is treated as a
 // Modified type.
 //
-// If oldDh or newDh are empty, we assume they are a hierarchy that is
+// If thisDh or thatDh are empty, we assume they are a hierarchy that is
 // completely empty. This is purely for helping callers create synthetic
 // InodeDeltas.
 //
+// Comparing this directory hierarchy to that directory hierarchy is that
+// sometimes it has few than all files, or may not have directories, etc.,
+// so lack of presence of entries in thisDh may not be reportable.
+//
 // NB: The order of the parameters matters (old, new) because Extra and
 //     Missing are considered as different discrepancy types.
-func Compare(oldDh, newDh *DirectoryHierarchy, keys []Keyword) ([]InodeDelta, error) {
+func Compare(thisDh, thatDh *DirectoryHierarchy, keys []Keyword) ([]InodeDelta, error) {
 	// Represents the new and old states for an entry.
 	type stateT struct {
 		Old *Entry
@@ -343,8 +347,8 @@ func Compare(oldDh, newDh *DirectoryHierarchy, keys []Keyword) ([]InodeDelta, er
 	diffs := map[string]*stateT{}
 
 	// First, iterate over the old hierarchy. If nil, pretend it's empty.
-	if oldDh != nil {
-		for _, e := range oldDh.Entries {
+	if thisDh != nil {
+		for _, e := range thisDh.Entries {
 			if e.Type == RelativeType || e.Type == FullType {
 				path, err := e.Path()
 				if err != nil {
@@ -365,8 +369,8 @@ func Compare(oldDh, newDh *DirectoryHierarchy, keys []Keyword) ([]InodeDelta, er
 	}
 
 	// Then, iterate over the new hierarchy. If nil, pretend it's empty.
-	if newDh != nil {
-		for _, e := range newDh.Entries {
+	if thatDh != nil {
+		for _, e := range thatDh.Entries {
 			if e.Type == RelativeType || e.Type == FullType {
 				path, err := e.Path()
 				if err != nil {