lisp/ob-scheme.el

   1 ;;; ob-scheme.el --- org-babel functions for Scheme
   2
   3 ;; Copyright (C) 2010-2014 Free Software Foundation, Inc.
   4
   5 ;; Authors: Eric Schulte
   6 ;;          Michael Gauland
   7 ;; Keywords: literate programming, reproducible research, scheme
   8 ;; Homepage: http://orgmode.org
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software: you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation, either version 3 of the License, or
  15 ;; (at your option) any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  24
  25 ;;; Commentary:
  26
  27 ;; Now working with SBCL for both session and external evaluation.
  28 ;;
  29 ;; This certainly isn't optimally robust, but it seems to be working
  30 ;; for the basic use cases.
  31
  32 ;;; Requirements:
  33
  34 ;; - a working scheme implementation
  35 ;;   (e.g. guile http://www.gnu.org/software/guile/guile.html)
  36 ;;
  37 ;; - for session based evaluation geiser is required, which is available from
  38 ;;   ELPA.
  39
  40 ;;; Code:
  41 (require 'ob)
  42 (require 'geiser nil t)
  43 (defvar geiser-repl--repl)             ; Defined in geiser-repl.el
  44 (defvar geiser-impl--implementation)   ; Defined in geiser-impl.el
  45 (defvar geiser-default-implementation) ; Defined in geiser-impl.el
  46 (defvar geiser-active-implementations) ; Defined in geiser-impl.el
  47
  48 (declare-function run-geiser "geiser-repl" (impl))
  49 (declare-function geiser-mode "geiser-mode" ())
  50 (declare-function geiser-eval-region "geiser-mode" (start end &optional and-go raw nomsg))
  51 (declare-function geiser-repl-exit "geiser-repl" (&optional arg))
  52
  53 (defvar org-babel-default-header-args:scheme '()
  54   "Default header arguments for scheme code blocks.")
  55
  56 (defun org-babel-expand-body:scheme (body params)
  57   "Expand BODY according to PARAMS, return the expanded body."
  58   (let ((vars (mapcar #'cdr (org-babel-get-header params :var))))
  59     (if (> (length vars) 0)
  60         (concat "(let ("
  61                 (mapconcat
  62                  (lambda (var) (format "%S" (print `(,(car var) ',(cdr var)))))
  63                  vars "\n      ")
  64                 ")\n" body ")")
  65       body)))
  66
  67
  68 (defvar org-babel-scheme-repl-map (make-hash-table :test 'equal)
  69   "Map of scheme sessions to session names.")
  70
  71 (defun org-babel-scheme-cleanse-repl-map ()
  72   "Remove dead buffers from the REPL map."
  73   (maphash
  74    (lambda (x y)
  75      (when (not (buffer-name y))
  76        (remhash x org-babel-scheme-repl-map)))
  77    org-babel-scheme-repl-map))
  78
  79 (defun org-babel-scheme-get-session-buffer (session-name)
  80   "Look up the scheme buffer for a session; return nil if it doesn't exist."
  81   (org-babel-scheme-cleanse-repl-map) ; Prune dead sessions
  82   (gethash session-name org-babel-scheme-repl-map))
  83
  84 (defun org-babel-scheme-set-session-buffer (session-name buffer)
  85   "Record the scheme buffer used for a given session."
  86   (puthash session-name buffer org-babel-scheme-repl-map))
  87
  88 (defun org-babel-scheme-get-buffer-impl (buffer)
  89   "Returns the scheme implementation geiser associates with the buffer."
  90   (with-current-buffer (set-buffer buffer)
  91     geiser-impl--implementation))
  92
  93 (defun org-babel-scheme-get-repl (impl name)
  94   "Switch to a scheme REPL, creating it if it doesn't exist:"
  95   (let ((buffer (org-babel-scheme-get-session-buffer name)))
  96     (or buffer
  97         (progn
  98           (run-geiser impl)
  99           (if name
 100               (progn
 101                 (rename-buffer name t)
 102                 (org-babel-scheme-set-session-buffer name (current-buffer))))
 103           (current-buffer)))))
 104
 105 (defun org-babel-scheme-make-session-name (buffer name impl)
 106   "Generate a name for the session buffer.
 107
 108 For a named session, the buffer name will be the session name.
 109
 110 If the session is unnamed (nil), generate a name.
 111
 112 If the session is 'none', use nil for the session name, and
 113 org-babel-scheme-execute-with-geiser will use a temporary session."
 114   (let ((result
 115          (cond ((not name)
 116                 (concat buffer " " (symbol-name impl) " REPL"))
 117                ((string= name "none") nil)
 118                (name))))
 119     result))
 120
 121 (defmacro org-babel-scheme-capture-current-message (&rest body)
 122   "Capture current message in both interactive and noninteractive mode"
 123   `(if noninteractive
 124        (let ((original-message (symbol-function 'message))
 125              (current-message nil))
 126          (unwind-protect
 127              (progn
 128                (defun message (&rest args)
 129                  (setq current-message (apply original-message args)))
 130                ,@body
 131                current-message)
 132            (fset 'message original-message)))
 133      (progn
 134        ,@body
 135        (current-message))))
 136
 137 (defun org-babel-scheme-execute-with-geiser (code output impl repl)
 138   "Execute code in specified REPL. If the REPL doesn't exist, create it
 139 using the given scheme implementation.
 140
 141 Returns the output of executing the code if the output parameter
 142 is true; otherwise returns the last value."
 143   (let ((result nil))
 144     (with-temp-buffer
 145       (insert (format ";; -*- geiser-scheme-implementation: %s -*-" impl))
 146       (newline)
 147       (insert (if output
 148                   (format "(with-output-to-string (lambda () %s))" code)
 149                 code))
 150       (geiser-mode)
 151       (let ((repl-buffer (save-current-buffer
 152                            (org-babel-scheme-get-repl impl repl))))
 153         (when (not (eq impl (org-babel-scheme-get-buffer-impl
 154                              (current-buffer))))
 155           (message "Implementation mismatch: %s (%s) %s (%s)" impl (symbolp impl)
 156                    (org-babel-scheme-get-buffer-impl (current-buffer))
 157                    (symbolp (org-babel-scheme-get-buffer-impl
 158                              (current-buffer)))))
 159         (setq geiser-repl--repl repl-buffer)
 160         (setq geiser-impl--implementation nil)
 161         (setq result (org-babel-scheme-capture-current-message
 162                       (geiser-eval-region (point-min) (point-max))))
 163         (setq result
 164               (if (and (stringp result) (equal (substring result 0 3) "=> "))
 165                   (replace-regexp-in-string "^=> " "" result)
 166                 "\"An error occurred.\""))
 167         (when (not repl)
 168           (save-current-buffer (set-buffer repl-buffer)
 169                                (geiser-repl-exit))
 170           (set-process-query-on-exit-flag (get-buffer-process repl-buffer) nil)
 171           (kill-buffer repl-buffer))
 172         (setq result (if (or (string= result "#<void>")
 173                              (string= result "#<unspecified>"))
 174                          nil
 175                        (read result)))))
 176     result))
 177
 178 (defun org-babel-execute:scheme (body params)
 179   "Execute a block of Scheme code with org-babel.
 180 This function is called by `org-babel-execute-src-block'"
 181   (let* ((source-buffer (current-buffer))
 182          (source-buffer-name (replace-regexp-in-string ;; zap surrounding *
 183                               "^ ?\\*\\([^*]+\\)\\*" "\\1"
 184                               (buffer-name source-buffer))))
 185     (save-excursion
 186       (org-babel-reassemble-table
 187        (let* ((result-type (cdr (assoc :result-type params)))
 188               (impl (or (when (cdr (assoc :scheme params))
 189                           (intern (cdr (assoc :scheme params))))
 190                         geiser-default-implementation
 191                         (car geiser-active-implementations)))
 192               (session (org-babel-scheme-make-session-name
 193                         source-buffer-name (cdr (assoc :session params)) impl))
 194               (full-body (org-babel-expand-body:scheme body params)))
 195          (org-babel-scheme-execute-with-geiser
 196           full-body                      ; code
 197           (string= result-type "output") ; output?
 198           impl                           ; implementation
 199           (and (not (string= session "none")) session))) ; session
 200        (org-babel-pick-name (cdr (assoc :colname-names params))
 201                             (cdr (assoc :colnames params)))
 202        (org-babel-pick-name (cdr (assoc :rowname-names params))
 203                             (cdr (assoc :rownames params)))))))
 204
 205 (provide 'ob-scheme)
 206
 207 ;;; ob-scheme.el ends here