ui: Improve output appearance when listing generations.

* guix/ui.scm (display-profile-content-diff): Use pretty-print-table to format
output.
(display-profile-content): Likewise.

Signed-off-by: Maxim Cournoyer <maxim.cournoyer@gmail.com>

1 files changed, 16 insertions, 13 deletions

diff --git a/guix/ui.scm b/guix/ui.scm
index 26a437e904..1428c254b3 100644
--- a/guix/ui.scm
+++ b/guix/ui.scm
@@ -16,6 +16,7 @@
 ;;; Copyright © 2019, 2021 Simon Tournier <zimon.toutoune@gmail.com>
 ;;; Copyright © 2020 Arun Isaac <arunisaac@systemreboot.net>
 ;;; Copyright © 2020 Maxim Cournoyer <maxim.cournoyer@gmail.com>
+;;; Copyright © 2018 Steve Sprang <scs@stevesprang.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -1889,10 +1890,10 @@ DURATION-RELATION with the current time."
   (define (equal-entry? first second)
     (string= (manifest-entry-item first) (manifest-entry-item second)))
 
-  (define (display-entry entry prefix)
+  (define (make-row entry prefix)
     (match entry
       (($ <manifest-entry> name version output location _)
-       (format #t " ~a ~a\t~a\t~a\t~a~%" prefix name version output location))))
+       (list (format #f " ~a ~a" prefix name) version output location))))
 
   (define (list-entries number)
     (manifest-entries (profile-manifest (generation-file-name profile number))))
@@ -1903,8 +1904,8 @@ DURATION-RELATION with the current time."
                   equal-entry? (list-entries new) (list-entries old)))
           (removed (lset-difference
                     equal-entry? (list-entries old) (list-entries new))))
-      (for-each (cut display-entry <> "+") added)
-      (for-each (cut display-entry <> "-") removed)
+      (pretty-print-table (append (map (cut make-row <> "+") added)
+                                  (map (cut make-row <> "-") removed)))
       (newline)))
 
   (display-diff profile gen1 gen2))
@@ -1932,15 +1933,17 @@ already taken."
 (define (display-profile-content profile number)
   "Display the packages in PROFILE, generation NUMBER, in a human-readable
 way."
-  (for-each (match-lambda
-              (($ <manifest-entry> name version output location _)
-               (format #t "  ~a\t~a\t~a\t~a~%"
-                       name version output location)))
-
-            ;; Show most recently installed packages last.
-            (reverse
-             (manifest-entries
-              (profile-manifest (generation-file-name profile number))))))
+
+  (define entry->row
+    (match-lambda
+      (($ <manifest-entry> name version output location _)
+       (list (string-append "  " name) version output location))))
+
+  (let* ((manifest (profile-manifest (generation-file-name profile number)))
+         (entries  (manifest-entries manifest))
+         (rows     (map entry->row entries)))
+    ;; Show most recently installed packages last.
+    (pretty-print-table (reverse rows))))
 
 (define (display-generation-change previous current)
   (format #t (G_ "switched from generation ~a to ~a~%") previous current))