[PATCH 2/7] emacs: Move code for evaluating to "guix-geiser.el".

[Alex Kost <alezost@gmail.com>]

* emacs/guix-backend.el: Adjust commentary. Move "eval" code to ...
  (guix-eval): Remove.
  (guix-eval-read, guix-eval-in-repl): Adjust to use new functions.
* emacs/guix-geiser.el: ...here.  New file.
  (guix-geiser-eval, guix-geiser-eval-read, guix-geiser-eval-in-repl):
  New functions.
---
 emacs/guix-backend.el | 39 ++++++++----------------------
 emacs/guix-geiser.el  | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 77 insertions(+), 29 deletions(-)
 create mode 100644 emacs/guix-geiser.el

diff --git a/emacs/guix-backend.el b/emacs/guix-backend.el
index 7e55bea..8ccfaa6 100644
--- a/emacs/guix-backend.el
+++ b/emacs/guix-backend.el
@@ -1,6 +1,6 @@
-;;; guix-backend.el --- Communication with Geiser
+;;; guix-backend.el --- Making and using Guix REPL
 
-;; Copyright © 2014 Alex Kost <alezost@gmail.com>
+;; Copyright © 2014, 2015 Alex Kost <alezost@gmail.com>
 
 ;; This file is part of GNU Guix.
 
@@ -19,9 +19,10 @@
 
 ;;; Commentary:
 
-;; This file provides the code for interacting with Guile using Geiser.
+;; This file provides the code for interacting with Guile using Guix REPL
+;; (Geiser REPL with some guix-specific additions).
 
-;; By default (if `guix-use-guile-server' is non-nil) 2 Geiser REPLs are
+;; By default (if `guix-use-guile-server' is non-nil) 2 Guix REPLs are
 ;; started.  The main one (with "guile --listen" process) is used for
 ;; "interacting" with a user - for showing a progress of
 ;; installing/deleting Guix packages.  The second (internal) REPL is
@@ -53,6 +54,7 @@
 
 (require 'geiser-mode)
 (require 'guix-emacs)
+(require 'guix-geiser)
 
 (defvar guix-load-path
   (file-name-directory (or load-file-name
@@ -315,28 +317,10 @@ additional internal REPL if it exists."
 (defvar guix-operation-buffer nil
   "Buffer from which the latest Guix operation was performed.")
 
-(defun guix-eval (str &optional wrap)
-  "Evaluate guile expression STR.
-If WRAP is non-nil, wrap STR into (begin ...) form.
-Return a list of strings with result values of evaluation."
-  (with-current-buffer (guix-get-repl-buffer 'internal)
-    (let* ((wrapped (if wrap (geiser-debug--wrap-region str) str))
-           (code `(:eval (:scm ,wrapped)))
-           (ret (geiser-eval--send/wait code)))
-      (if (geiser-eval--retort-error ret)
-          (error "Error in evaluating guile expression: %s"
-                 (geiser-eval--retort-output ret))
-        (cdr (assq 'result ret))))))
-
 (defun guix-eval-read (str &optional wrap)
-  "Evaluate guile expression STR.
-For the meaning of WRAP, see `guix-eval'.
-Return elisp expression of the first result value of evaluation."
-  ;; Parsing scheme code with elisp `read' is probably not the best idea.
-  (read (replace-regexp-in-string
-         "#f\\|#<unspecified>" "nil"
-         (replace-regexp-in-string
-          "#t" "t" (car (guix-eval str wrap))))))
+  "Evaluate STR with guile expression using Guix REPL.
+See `guix-geiser-eval-read' for details."
+  (guix-geiser-eval-read str wrap (guix-get-repl-buffer 'internal)))
 
 (defun guix-eval-in-repl (str &optional operation-buffer operation-type)
   "Switch to Guix REPL and evaluate STR with guile expression there.
@@ -350,10 +334,7 @@ successful executing of the current operation,
   (setq guix-repl-operation-p t
         guix-repl-operation-type operation-type
         guix-operation-buffer operation-buffer)
-  (let ((repl (guix-get-repl-buffer)))
-    (with-current-buffer repl
-      (geiser-repl--send str))
-    (geiser-repl--switch-to-buffer repl)))
+  (guix-geiser-eval-in-repl str (guix-get-repl-buffer)))
 
 (provide 'guix-backend)
 
diff --git a/emacs/guix-geiser.el b/emacs/guix-geiser.el
new file mode 100644
index 0000000..1f0cf72
--- /dev/null
+++ b/emacs/guix-geiser.el
@@ -0,0 +1,67 @@
+;;; guix-geiser.el --- Interacting with Geiser
+
+;; Copyright © 2015 Alex Kost <alezost@gmail.com>
+
+;; This file is part of GNU Guix.
+
+;; GNU Guix is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Guix is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This file provides functions to evaluate guile code using Geiser.
+
+;;; Code:
+
+(require 'geiser-mode)
+
+(defun guix-geiser-repl ()
+  "Return the current Geiser REPL."
+  (or geiser-repl--repl
+      (geiser-repl--repl/impl 'guile)
+      (error "Geiser REPL not found")))
+
+(defun guix-geiser-eval (str &optional wrap repl)
+  "Evaluate STR with guile expression using Geiser REPL.
+If REPL is nil, use the current Geiser REPL.
+If WRAP is non-nil, wrap STR into (begin ...) form.
+Return a list of strings with result values of evaluation."
+  (with-current-buffer (or repl (guix-geiser-repl))
+    (let* ((wrapped (if wrap (geiser-debug--wrap-region str) str))
+           (code `(:eval (:scm ,wrapped)))
+           (ret (geiser-eval--send/wait code)))
+      (if (geiser-eval--retort-error ret)
+          (error "Error in evaluating guile expression: %s"
+                 (geiser-eval--retort-output ret))
+        (cdr (assq 'result ret))))))
+
+(defun guix-geiser-eval-read (str &optional wrap repl)
+  "Evaluate STR with guile expression using Geiser REPL.
+For the meaning of WRAP, see `guix-geiser-eval'.
+Return elisp expression of the first result value of evaluation."
+  ;; Parsing scheme code with elisp `read' is probably not the best idea.
+  (read (replace-regexp-in-string
+         "#f\\|#<unspecified>" "nil"
+         (replace-regexp-in-string
+          "#t" "t" (car (guix-geiser-eval str wrap repl))))))
+
+(defun guix-geiser-eval-in-repl (str &optional repl)
+  "Switch to Geiser REPL and evaluate STR with guile expression there."
+  (if repl
+      (geiser-repl--switch-to-buffer repl)
+    (geiser--go-to-repl))
+  (geiser-repl--send str))
+
+(provide 'guix-geiser)
+
+;;; guix-geiser.el ends here
-- 
2.4.3