From 655d0c1e870d8957974961c8bfc989a75096c60a Mon Sep 17 00:00:00 2001
From: Michael Gauland <mike_gauland@stanfordalumni.org>
Date: Sat, 5 Jan 2013 08:03:19 +1300
Subject: [PATCH] Modify ob-scheme.el to use geiser.

---
 lisp/ob-scheme.el |  198 ++++++++++++++++++++++++++++++++--------------------
 1 files changed, 122 insertions(+), 76 deletions(-)

diff --git a/lisp/ob-scheme.el b/lisp/ob-scheme.el
index 74e9a94..9e39c72 100644
--- a/lisp/ob-scheme.el
+++ b/lisp/ob-scheme.el
@@ -1,8 +1,8 @@
 ;;; ob-scheme.el --- org-babel functions for Scheme
 
-;; Copyright (C) 2010-2013  Free Software Foundation, Inc.
+;; Copyright (C) 2010-2012  Free Software Foundation, Inc.
 
-;; Author: Eric Schulte
+;; Authors: Eric Schulte, Michael Gauland
 ;; Keywords: literate programming, reproducible research, scheme
 ;; Homepage: http://orgmode.org
 
@@ -33,27 +33,16 @@
 ;; - a working scheme implementation
 ;;   (e.g. guile http://www.gnu.org/software/guile/guile.html)
 ;;
-;; - for session based evaluation cmuscheme.el is required which is
-;;   included in Emacs
+;; - for session based evaluation geiser is required, which is available from
+;;   ELPA.
 
 ;;; Code:
 (require 'ob)
-(eval-when-compile (require 'cl))
-
-(declare-function run-scheme "ext:cmuscheme" (cmd))
+(load-library "geiser-impl")
 
 (defvar org-babel-default-header-args:scheme '()
   "Default header arguments for scheme code blocks.")
 
-(defvar org-babel-scheme-eoe "org-babel-scheme-eoe"
-  "String to indicate that evaluation has completed.")
-
-(defcustom org-babel-scheme-cmd "guile"
-  "Name of command used to evaluate scheme blocks."
-  :group 'org-babel
-  :version "24.1"
-  :type 'string)
-
 (defun org-babel-expand-body:scheme (body params)
   "Expand BODY according to PARAMS, return the expanded body."
   (let ((vars (mapcar #'cdr (org-babel-get-header params :var))))
@@ -65,70 +54,127 @@
                 ")\n" body ")")
       body)))
 
-(defvar scheme-program-name)
+
+(defvar org-babel-scheme-repl-map (make-hash-table :test 'equal)
+  "Map of scheme sessions to session names.")
+
+(defun cleanse-org-babel-scheme-repl-map ()
+  "Remove dead buffers from the REPL map."
+  (maphash
+   (lambda (x y)
+     (when (not (buffer-name y))
+       (remhash x org-babel-scheme-repl-map)))
+   org-babel-scheme-repl-map))
+
+(defun org-babel-scheme-get-session-buffer (session-name)
+  "Look up the scheme buffer for a session; return nil if it doesn't exist."
+  (cleanse-org-babel-scheme-repl-map) ; Prune dead sessions
+  (gethash session-name org-babel-scheme-repl-map))
+
+(defun org-babel-scheme-set-session-buffer (session-name buffer)
+  "Record the scheme buffer used for a given session."
+  (puthash session-name buffer org-babel-scheme-repl-map))
+
+(defun org-babel-scheme-get-buffer-impl (buffer)
+  "Returns the scheme implementation geiser associates with the buffer."
+  (with-current-buffer (set-buffer buffer)
+    geiser-impl--implementation))
+
+(defun org-babel-scheme-get-repl (impl name)
+  "Switch to a scheme REPL, creating it if it doesn't exist:"
+  (let ((buffer (org-babel-scheme-get-session-buffer name)))
+    (or buffer 
+    (progn
+      (run-geiser impl)
+      (if name
+	  (progn 
+	    (rename-buffer name t)
+	    (org-babel-scheme-set-session-buffer name (current-buffer)))
+	)
+      (current-buffer)
+  ))))
+
+(defun org-babel-scheme-make-session-name (buffer name impl)
+  "Generate a name for the session buffer.
+
+For a named session, the buffer name will be the session name.
+
+If the session is unnamed (nil), generate a name.
+
+If the session is 'none', use nil for the session name, and
+org-babel-scheme-execute-with-geiser will use a temporary session."
+  (let ((result 
+	 (cond ((not name)
+		(concat buffer " " (symbol-name impl) " REPL"))
+	       ((string= name "none") nil)
+	       (name))))
+    result))
+
+(defun org-babel-scheme-execute-with-geiser (code output impl repl)
+  "Execute code in specified REPL. If the REPL doesn't exist, create it
+using the given scheme implementation.
+
+Returns the output of executing the code if the output parameter
+is true; otherwise returns the last value."
+  (let ((result nil))
+    (with-temp-buffer
+      (insert (format ";; -*- geiser-scheme-implementation: %s -*-" impl))
+      (newline)
+      (insert (if output
+		  (format "(with-output-to-string (lambda () %s))" code)
+		code)
+	      )
+      (geiser-mode)
+      (let ((repl-buffer (save-current-buffer (org-babel-scheme-get-repl impl repl))))
+	(when (not (eq impl (org-babel-scheme-get-buffer-impl (current-buffer))))
+	  (message "Implementation mismatch: %s (%s) %s (s)" impl (symbolp impl)
+		   (org-babel-scheme-get-buffer-impl (current-buffer))
+		   (symbolp (org-babel-scheme-get-buffer-impl (current-buffer)))))
+	(setq geiser-repl--repl repl-buffer)
+	(setq geiser-impl--implementation nil)
+	(geiser-eval-region (point-min) (point-max))
+	(setq result
+	      (if (equal (substring (current-message) 0 3) "=> ")
+		  (replace-regexp-in-string "^=> " "" (current-message))
+		"\"An error occurred.\""))
+	(when (not repl)
+	  (save-current-buffer (set-buffer repl-buffer)
+			       (geiser-repl-exit))
+	  (set-process-query-on-exit-flag (get-buffer-process repl-buffer) nil)
+	  (kill-buffer repl-buffer))
+	(setq result (if (or (string= result "#<void>")
+			     (string= result "#<unspecified>"))
+			 nil
+		       (read result)))))
+    result
+    ))
+
 (defun org-babel-execute:scheme (body params)
   "Execute a block of Scheme code with org-babel.
 This function is called by `org-babel-execute-src-block'"
-  (let* ((result-type (cdr (assoc :result-type params)))
-	 (org-babel-scheme-cmd (or (cdr (assoc :scheme params))
-				   org-babel-scheme-cmd))
-         (full-body (org-babel-expand-body:scheme body params)))
-    (read
-     (if (not (string= (cdr (assoc :session params)) "none"))
-         ;; session evaluation
-	 (let ((session (org-babel-prep-session:scheme
-			 (cdr (assoc :session params)) params)))
-	   (org-babel-comint-with-output
-	       (session (format "%S" org-babel-scheme-eoe) t body)
-	     (mapc
-	      (lambda (line)
-		(insert (org-babel-chomp line)) (comint-send-input nil t))
-	      (list body (format "%S" org-babel-scheme-eoe)))))
-       ;; external evaluation
-       (let ((script-file (org-babel-temp-file "scheme-script-")))
-         (with-temp-file script-file
-           (insert
-            ;; return the value or the output
-            (if (string= result-type "value")
-                (format "(display %s)" full-body)
-              full-body)))
-         (org-babel-eval
-	  (format "%s %s" org-babel-scheme-cmd
-		  (org-babel-process-file-name script-file)) ""))))))
-
-(defun org-babel-prep-session:scheme (session params)
-  "Prepare SESSION according to the header arguments specified in PARAMS."
-  (let* ((session (org-babel-scheme-initiate-session session))
-	 (vars (mapcar #'cdr (org-babel-get-header params :var)))
-	 (var-lines
-	  (mapcar
-	   (lambda (var) (format "%S" (print `(define ,(car var) ',(cdr var)))))
-	   vars)))
-    (when session
-      (org-babel-comint-in-buffer session
-	(sit-for .5) (goto-char (point-max))
-	(mapc (lambda (var)
-		(insert var) (comint-send-input nil t)
-		(org-babel-comint-wait-for-output session)
-		(sit-for .1) (goto-char (point-max))) var-lines)))
-    session))
-
-(defun org-babel-scheme-initiate-session (&optional session)
-  "If there is not a current inferior-process-buffer in SESSION
-then create.  Return the initialized session."
-  (require 'cmuscheme)
-  (unless (string= session "none")
-    (let ((session-buffer (save-window-excursion
-			    (run-scheme org-babel-scheme-cmd)
-			    (rename-buffer session)
-			    (current-buffer))))
-      (if (org-babel-comint-buffer-livep session-buffer)
-	  (progn (sit-for .25) session-buffer)
-        (sit-for .5)
-        (org-babel-scheme-initiate-session session)))))
+  (let* ((source-buffer (current-buffer))
+	 (source-buffer-name (replace-regexp-in-string ;; zap surrounding *
+	  "^ ?\\*\\([^*]+\\)\\*" "\\1" (buffer-name source-buffer))))
+    (save-excursion
+      (org-babel-reassemble-table
+       (let* ((result-type (cdr (assoc :result-type params)))
+	      (impl (or (when (cdr (assoc :scheme params))
+			  (intern (cdr (assoc :scheme params))))
+			geiser-default-implementation
+			(car geiser-active-implementations)))
+	      (session (org-babel-scheme-make-session-name source-buffer-name (cdr (assoc :session params)) impl))
+	    (full-body (org-babel-expand-body:scheme body params)))
+       (org-babel-scheme-execute-with-geiser full-body           ; code
+					     (string= result-type "output")	; output?
+					     impl ; implementation
+					     (and (not (string= session "none")) session)); session
+       )
+     (org-babel-pick-name (cdr (assoc :colname-names params))
+			  (cdr (assoc :colnames params)))
+    (org-babel-pick-name (cdr (assoc :rowname-names params))
+			 (cdr (assoc :rownames params)))))))
+  
 
 (provide 'ob-scheme)
 
-
-
 ;;; ob-scheme.el ends here
-- 
1.7.2.5