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 (defun org-babel-scheme-execute-with-geiser (code output impl repl)
 122   "Execute code in specified REPL. If the REPL doesn't exist, create it
 123 using the given scheme implementation.
 124
 125 Returns the output of executing the code if the output parameter
 126 is true; otherwise returns the last value."
 127   (let ((result nil))
 128     (with-temp-buffer
 129       (insert (format ";; -*- geiser-scheme-implementation: %s -*-" impl))
 130       (newline)
 131       (insert (if output
 132                   (format "(with-output-to-string (lambda () %s))" code)
 133                 code))
 134       (geiser-mode)
 135       (let ((repl-buffer (save-current-buffer
 136                            (org-babel-scheme-get-repl impl repl))))
 137         (when (not (eq impl (org-babel-scheme-get-buffer-impl
 138                              (current-buffer))))
 139           (message "Implementation mismatch: %s (%s) %s (%s)" impl (symbolp impl)
 140                    (org-babel-scheme-get-buffer-impl (current-buffer))
 141                    (symbolp (org-babel-scheme-get-buffer-impl
 142                              (current-buffer)))))
 143         (setq geiser-repl--repl repl-buffer)
 144         (setq geiser-impl--implementation nil)
 145         (geiser-eval-region (point-min) (point-max))
 146         (setq result
 147               (if (equal (substring (current-message) 0 3) "=> ")
 148                   (replace-regexp-in-string "^=> " "" (current-message))
 149                 "\"An error occurred.\""))
 150         (when (not repl)
 151           (save-current-buffer (set-buffer repl-buffer)
 152                                (geiser-repl-exit))
 153           (set-process-query-on-exit-flag (get-buffer-process repl-buffer) nil)
 154           (kill-buffer repl-buffer))
 155         (setq result (if (or (string= result "#<void>")
 156                              (string= result "#<unspecified>"))
 157                          nil
 158                        (read result)))))
 159     result))
 160
 161 (defun org-babel-execute:scheme (body params)
 162   "Execute a block of Scheme code with org-babel.
 163 This function is called by `org-babel-execute-src-block'"
 164   (let* ((source-buffer (current-buffer))
 165          (source-buffer-name (replace-regexp-in-string ;; zap surrounding *
 166                               "^ ?\\*\\([^*]+\\)\\*" "\\1"
 167                               (buffer-name source-buffer))))
 168     (save-excursion
 169       (org-babel-reassemble-table
 170        (let* ((result-type (cdr (assoc :result-type params)))
 171               (impl (or (when (cdr (assoc :scheme params))
 172                           (intern (cdr (assoc :scheme params))))
 173                         geiser-default-implementation
 174                         (car geiser-active-implementations)))
 175               (session (org-babel-scheme-make-session-name
 176                         source-buffer-name (cdr (assoc :session params)) impl))
 177               (full-body (org-babel-expand-body:scheme body params)))
 178          (org-babel-scheme-execute-with-geiser
 179           full-body                      ; code
 180           (string= result-type "output") ; output?
 181           impl                           ; implementation
 182           (and (not (string= session "none")) session))) ; session
 183        (org-babel-pick-name (cdr (assoc :colname-names params))
 184                             (cdr (assoc :colnames params)))
 185        (org-babel-pick-name (cdr (assoc :rowname-names params))
 186                             (cdr (assoc :rownames params)))))))
 187
 188 (provide 'ob-scheme)
 189
 190 ;;; ob-scheme.el ends here