03/20: emacs: Add 'guix-package-names'.

[Alex Kost]

alezost pushed a commit to branch wip-emacs-popup-ui
in repository guix.

commit cc260076584cf348ef9097f83aaf1c55685227af
Author: Alex Kost <address@hidden>
Date:   Wed Aug 12 14:40:47 2015 +0300

    emacs: Add 'guix-package-names'.
    
    * emacs/guix-main.scm (package-names, package-names-lists): New procedures.
    * emacs/guix-base.el (guix-package-names): New variable and function.
---
 emacs/guix-base.el  |   20 ++++++++++++++++++++
 emacs/guix-main.scm |   12 ++++++++++++
 2 files changed, 32 insertions(+), 0 deletions(-)

diff --git a/emacs/guix-base.el b/emacs/guix-base.el
index bfb535e..7ec68ec 100644
--- a/emacs/guix-base.el
+++ b/emacs/guix-base.el
@@ -193,6 +193,26 @@ If PATH is relative, it is considered to be relative to
             (guix-eval-read
              (guix-make-guile-expression 'lint-checker-names)))))
 
+(defvar guix-package-names nil
+  "List of names of available packages.")
+
+(defun guix-package-names ()
+  "Return a list of names of available packages."
+  (or guix-package-names
+      (setq guix-package-names
+            (sort
+             ;; Work around <https://github.com/jaor/geiser/issues/64>:
+             ;; list of strings is parsed much slower than list of lists,
+             ;; so we use 'package-names-lists' instead of 'package-names'.
+
+             ;; (guix-eval-read (guix-make-guile-expression
+             ;;                  'package-names))
+
+             (mapcar #'car
+                     (guix-eval-read (guix-make-guile-expression
+                                      'package-names-lists)))
+             #'string<))))
+
 
 ;;; Buffers and auto updating.
 
diff --git a/emacs/guix-main.scm b/emacs/guix-main.scm
index 2c5b0ba..90d76cc 100644
--- a/emacs/guix-main.scm
+++ b/emacs/guix-main.scm
@@ -937,3 +937,15 @@ GENERATIONS is a list of generation numbers."
   (map (lambda (checker)
          (symbol->string (lint-checker-name checker)))
        %checkers))
+
+;; TODO Put in (gnu packages)?
+(define (package-names)
+  "Return a list of names of available packages."
+  (delete-duplicates
+   (fold-packages (lambda (pkg res)
+                    (cons (package-name pkg) res))
+                  '())))
+
+;; See the comment to 'guix-package-names' function in "guix-popup.el".
+(define (package-names-lists)
+  (map list (package-names)))