add pttodo.NewRootFromFiles

pttodo/root.go

@@ -13,6 +13,19 @@ type Root struct {
 	Done      []Todo
 }
 
+func NewRootFromFiles(p ...string) (Root, error) {
+	var result Root
+	for _, p := range p {
+		subroot, err := NewRootFromFile(p)
+		if err != nil {
+			return Root{}, err
+		}
+		result.MergeIn(subroot)
+	}
+	result.AutoMove()
+	return result, nil
+}
+
 func NewRootFromFile(p string) (Root, error) {
 	if b, err := os.ReadFile(p); err == nil && len(bytes.TrimSpace(b)) == 0 {
 		return Root{}, nil