.

wcfs/internal/xbtree/blib/blib.go

@@ -43,8 +43,8 @@ const KeyMin Key = math.MinInt64
 type setOid = set.Oid
 
 
-// kstr formats key as string.
-func kstr(k Key) string {
+// KStr formats key as string.
+func KStr(k Key) string {
 	if k == KeyMin {
 		return "-∞"
 	}

wcfs/internal/xbtree/blib/rangeset.go

@@ -380,11 +380,11 @@ func (S RangedKeySet) String() string {
 func (r KeyRange) String() string {
 	var shi string
 	if r.Hi_ == KeyMax {
-		shi = kstr(r.Hi_) // ∞
+		shi = KStr(r.Hi_) // ∞
 	} else {
 		shi = fmt.Sprintf("%d", r.Hi_+1)
 	}
-	return fmt.Sprintf("[%s,%s)", kstr(r.Lo), shi)
+	return fmt.Sprintf("[%s,%s)", KStr(r.Lo), shi)
 }
 
 

wcfs/internal/xbtree/treediff.go

@@ -995,29 +995,6 @@ func pop(nodeStk *[]*nodeInRange) *nodeInRange {
 	return top
 }
 
-// pathEqual returns whether two paths are the same.
-func pathEqual(patha, pathb []zodb.Oid) bool {
-	if len(patha) != len(pathb) {
-		return false
-	}
-	for i, a := range patha {
-		if pathb[i] != a {
-			return false
-		}
-	}
-	return true
-}
-
-// vnode returns brief human-readable representation of node.
-func vnode(node Node) string {
-	kind := "?"
-	switch node.(type) {
-	case *Tree:   kind = "T"
-	case *Bucket: kind = "B"
-	}
-	return kind + node.POid().String()
-}
-
 func tracefDiff(format string, argv ...interface{}) {
 	if traceDiff {
 		fmt.Printf(format, argv...)

wcfs/internal/xbtree/xbtree.go

@@ -35,6 +35,9 @@ import (
 )
 
 
+// this file contains only tree types and utilities.
+// main code lives in δbtail.go and treediff.go .
+
 // XXX instead of generics
 type Tree   = blib.Tree
 type Bucket = blib.Bucket
@@ -59,7 +62,6 @@ type setTid = set.Tid
 
 
 // nodePathToPath converts path from []Node to []Oid.
-// XXX place = ?  -> δbtail.go/treediff.go (close to pathEqual), or move them both to misc.go
 func nodePathToPath(nodePath []Node) (path []zodb.Oid) {
 	// assert nodePath = Tree Tree ... Tree Bucket
 	l := len(nodePath)
@@ -84,16 +86,32 @@ func nodePathToPath(nodePath []Node) (path []zodb.Oid) {
 	return path
 }
 
-
-// kstr formats key as string.
-func kstr(k Key) string {
-	if k == KeyMin {
-		return "-∞"
+// pathEqual returns whether two paths are the same.
+func pathEqual(patha, pathb []zodb.Oid) bool {
+	if len(patha) != len(pathb) {
+		return false
 	}
-	if k == KeyMax {
-		return "∞"
+	for i, a := range patha {
+		if pathb[i] != a {
+			return false
+		}
 	}
-	return fmt.Sprintf("%d", k)
+	return true
+}
+
+// vnode returns brief human-readable representation of node.
+func vnode(node Node) string {
+	kind := "?"
+	switch node.(type) {
+	case *Tree:   kind = "T"
+	case *Bucket: kind = "B"
+	}
+	return kind + node.POid().String()
+}
+
+
+func kstr(key Key) string {
+	return blib.KStr(key)
 }
 
 func panicf(format string, argv ...interface{}) {

wcfs/internal/xbtree/δbtail.go

@@ -270,7 +270,7 @@ func (δBtail *ΔBtail) track(key Key, path []zodb.Oid) {
 		tracefΔBtail("->T: nop\n")
 		path_ := δBtail.trackSet.Path(leaf)
 		if !pathEqual(path, path_) {
-			panicf("BUG: key %s is already tracked via path=%v\ntrack requests path=%v",  kstr(key), path_, path)
+			panicf("BUG: key %s is already tracked via path=%v\ntrack requests path=%v", kstr(key), path_, path)
 		}
 		return
 	}
@@ -798,7 +798,7 @@ func (δBtail *ΔBtail) GetAt(root zodb.Oid, key Key, at zodb.Tid) (value Value,
 		panicf("δBtail: root<%s> not tracked", root)
 	}
 
-	// TODO -> index lastRevOf(key) | linear scan ↓ looking for change <= at
+	// TODO -> index lastRevOf(key) | linear scan ↓ looking for change ≤ at
 	for i := len(δTtail.vδT)-1; i >= 0; i-- {
 		δT := δTtail.vδT[i]
 		δvalue, ok_ := δT.KV[key]