some more cleanup

bin/gpg-key-to-datamatrix

@@ -1,10 +1,14 @@
 #! /usr/bin/env nix-shell
 #! nix-shell -p typst dmtx-utils nushell -i nu
 
+def append-if [cond: bool, item: any] {
+  if $cond { $in | append $item } else { $in }
+}
+
 def get-chunked-key [keyid?: string] {
   let flags = [
     "--export-secret-key", "--export-options", "export-minimal"
-  ] | do { if keyid == null { $in } else { $in | append $keyid}}
+  ] | append-if ($keyid != null) $keyid
   let key = (gpg ...$flags)
   let length = ($key | bytes length)
   # 1555 is the maximum length in bytes split data evenly