[bug#33448] [PATCH 1/3] describe: Use a procedure to format output.

[Oleg Pykhalov <go.wigust@gmail.com>]

* guix/channels.scm (channel->sexp): New procedure.
* guix/scripts/describe.scm (display-checkout-info, display-profile-info): Use
this.
---
 guix/channels.scm         |  9 +++++++
 guix/scripts/describe.scm | 57 ++++++++++++++++++++-------------------
 2 files changed, 38 insertions(+), 28 deletions(-)

diff --git a/guix/channels.scm b/guix/channels.scm
index 82389eb58..bfdbf470b 100644
--- a/guix/channels.scm
+++ b/guix/channels.scm
@@ -39,6 +39,7 @@
             channel-commit
             channel-location
 
+            channel->sexp
             %default-channels
 
             channel-instance?
@@ -85,6 +86,14 @@
   "Return true if CHANNEL is the 'guix' channel."
   (eq? 'guix (channel-name channel)))
 
+(define channel->sexp
+  (match-lambda
+    (($ <channel> name url branch commit location)
+     `(channel
+       (name ,name)
+       (url ,url)
+       (commit ,commit)))))
+
 (define-record-type <channel-instance>
   (channel-instance channel commit checkout)
   channel-instance?
diff --git a/guix/scripts/describe.scm b/guix/scripts/describe.scm
index d817d7f7c..6a30d19b1 100644
--- a/guix/scripts/describe.scm
+++ b/guix/scripts/describe.scm
@@ -18,6 +18,7 @@
 
 (define-module (guix scripts describe)
   #:use-module ((guix ui) #:hide (display-profile-content))
+  #:use-module (guix channels)
   #:use-module (guix scripts)
   #:use-module (guix describe)
   #:use-module (guix profiles)
@@ -104,10 +105,9 @@ within a Git checkout."
        (format #t (G_ "  branch: ~a~%") (reference-shorthand head))
        (format #t (G_ "  commit: ~a~%") commit))
       ('channels
-       (pretty-print `(list (channel
-                             (name 'guix)
-                             (url ,(dirname directory))
-                             (commit ,commit))))))
+       (pretty-print (channel->sexp (channel (name 'guix)
+                                             (url (dirname directory))
+                                             (commit commit))))))
     (display-package-search-path fmt)))
 
 (define (display-profile-info profile fmt)
@@ -116,34 +116,35 @@ in the format specified by FMT."
   (define number
     (generation-number profile))
 
+  (define (channels)
+    (map (lambda (entry)
+           (match (assq 'source (manifest-entry-properties entry))
+             (('source ('repository ('version 0)
+                                    ('url url)
+                                    ('branch branch)
+                                    ('commit commit)
+                                    _ ...))
+              (channel (name (string->symbol (manifest-entry-name entry)))
+                       (url url)
+                       (commit commit)))
+
+             ;; Pre-0.15.0 Guix does not provide that information,
+             ;; so there's not much we can do in that case.
+             (_ '???)))
+
+         ;; Show most recently installed packages last.
+         (reverse
+          (manifest-entries
+           (profile-manifest
+            (if (zero? number)
+                profile
+                (generation-file-name profile number)))))))
+
   (match fmt
     ('human
      (display-profile-content profile number))
     ('channels
-     (pretty-print
-      `(list ,@(map (lambda (entry)
-                      (match (assq 'source (manifest-entry-properties entry))
-                        (('source ('repository ('version 0)
-                                               ('url url)
-                                               ('branch branch)
-                                               ('commit commit)
-                                               _ ...))
-                         `(channel (name ',(string->symbol
-                                            (manifest-entry-name entry)))
-                                   (url ,url)
-                                   (commit ,commit)))
-
-                        ;; Pre-0.15.0 Guix does not provide that information,
-                        ;; so there's not much we can do in that case.
-                        (_ '???)))
-
-                    ;; Show most recently installed packages last.
-                    (reverse
-                     (manifest-entries
-                      (profile-manifest
-                       (if (zero? number)
-                           profile
-                           (generation-file-name profile number))))))))))
+     (pretty-print (map channel->sexp (channels)))))
   (display-package-search-path fmt))
 
 \f
-- 
2.19.1