lisp/org/ob-scheme.el

   1 ;;; ob-scheme.el --- org-babel functions for Scheme
   2
   3 ;; Copyright (C) 2010-2016 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 "ext:geiser-repl" (impl))
  49 (declare-function geiser-mode "ext:geiser-mode" ())
  50 (declare-function geiser-eval-region "ext:geiser-mode"
  51                   (start end &optional and-go raw nomsg))
  52 (declare-function geiser-repl-exit "ext:geiser-repl" (&optional arg))
  53
  54 (defvar org-babel-default-header-args:scheme '()
  55   "Default header arguments for scheme code blocks.")
  56
  57 (defun org-babel-expand-body:scheme (body params)
  58   "Expand BODY according to PARAMS, return the expanded body."
  59   (let ((vars (mapcar #'cdr (org-babel-get-header params :var))))
  60     (if (> (length vars) 0)
  61         (concat "(let ("
  62                 (mapconcat
  63                  (lambda (var) (format "%S" (print `(,(car var) ',(cdr var)))))
  64                  vars "\n      ")
  65                 ")\n" body ")")
  66       body)))
  67
  68
  69 (defvar org-babel-scheme-repl-map (make-hash-table :test 'equal)
  70   "Map of scheme sessions to session names.")
  71
  72 (defun org-babel-scheme-cleanse-repl-map ()
  73   "Remove dead buffers from the REPL map."
  74   (maphash
  75    (lambda (x y)
  76      (when (not (buffer-name y))
  77        (remhash x org-babel-scheme-repl-map)))
  78    org-babel-scheme-repl-map))
  79
  80 (defun org-babel-scheme-get-session-buffer (session-name)
  81   "Look up the scheme buffer for a session; return nil if it doesn't exist."
  82   (org-babel-scheme-cleanse-repl-map) ; Prune dead sessions
  83   (gethash session-name org-babel-scheme-repl-map))
  84
  85 (defun org-babel-scheme-set-session-buffer (session-name buffer)
  86   "Record the scheme buffer used for a given session."
  87   (puthash session-name buffer org-babel-scheme-repl-map))
  88
  89 (defun org-babel-scheme-get-buffer-impl (buffer)
  90   "Returns the scheme implementation geiser associates with the buffer."
  91   (with-current-buffer (set-buffer buffer)
  92     geiser-impl--implementation))
  93
  94 (defun org-babel-scheme-get-repl (impl name)
  95   "Switch to a scheme REPL, creating it if it doesn't exist:"
  96   (let ((buffer (org-babel-scheme-get-session-buffer name)))
  97     (or buffer
  98         (progn
  99           (run-geiser impl)
 100           (if name
 101               (progn
 102                 (rename-buffer name t)
 103                 (org-babel-scheme-set-session-buffer name (current-buffer))))
 104           (current-buffer)))))
 105
 106 (defun org-babel-scheme-make-session-name (buffer name impl)
 107   "Generate a name for the session buffer.
 108
 109 For a named session, the buffer name will be the session name.
 110
 111 If the session is unnamed (nil), generate a name.
 112
 113 If the session is `none', use nil for the session name, and
 114 org-babel-scheme-execute-with-geiser will use a temporary session."
 115   (let ((result
 116          (cond ((not name)
 117                 (concat buffer " " (symbol-name impl) " REPL"))
 118                ((string= name "none") nil)
 119                (name))))
 120     result))
 121
 122 (defun org-babel-scheme-execute-with-geiser (code output impl repl)
 123   "Execute code in specified REPL. If the REPL doesn't exist, create it
 124 using the given scheme implementation.
 125
 126 Returns the output of executing the code if the output parameter
 127 is true; otherwise returns the last value."
 128   (let ((result nil))
 129     (with-temp-buffer
 130       (insert (format ";; -*- geiser-scheme-implementation: %s -*-" impl))
 131       (newline)
 132       (insert (if output
 133                   (format "(with-output-to-string (lambda () %s))" code)
 134                 code))
 135       (geiser-mode)
 136       (let ((repl-buffer (save-current-buffer
 137                            (org-babel-scheme-get-repl impl repl))))
 138         (when (not (eq impl (org-babel-scheme-get-buffer-impl
 139                              (current-buffer))))
 140           (message "Implementation mismatch: %s (%s) %s (%s)" impl (symbolp impl)
 141                    (org-babel-scheme-get-buffer-impl (current-buffer))
 142                    (symbolp (org-babel-scheme-get-buffer-impl
 143                              (current-buffer)))))
 144         (setq geiser-repl--repl repl-buffer)
 145         (setq geiser-impl--implementation nil)
 146         (geiser-eval-region (point-min) (point-max))
 147         (setq result
 148               (if (equal (substring (current-message) 0 3) "=> ")
 149                   (replace-regexp-in-string "^=> " "" (current-message))
 150                 "\"An error occurred.\""))
 151         (when (not repl)
 152           (save-current-buffer (set-buffer repl-buffer)
 153                                (geiser-repl-exit))
 154           (set-process-query-on-exit-flag (get-buffer-process repl-buffer) nil)
 155           (kill-buffer repl-buffer))
 156         (setq result (if (or (string= result "#<void>")
 157                              (string= result "#<unspecified>"))
 158                          nil
 159                        (read result)))))
 160     result))
 161
 162 (defun org-babel-execute:scheme (body params)
 163   "Execute a block of Scheme code with org-babel.
 164 This function is called by `org-babel-execute-src-block'"
 165   (let* ((source-buffer (current-buffer))
 166          (source-buffer-name (replace-regexp-in-string ;; zap surrounding *
 167                               "^ ?\\*\\([^*]+\\)\\*" "\\1"
 168                               (buffer-name source-buffer))))
 169     (save-excursion
 170       (org-babel-reassemble-table
 171        (let* ((result-type (cdr (assoc :result-type params)))
 172               (impl (or (when (cdr (assoc :scheme params))
 173                           (intern (cdr (assoc :scheme params))))
 174                         geiser-default-implementation
 175                         (car geiser-active-implementations)))
 176               (session (org-babel-scheme-make-session-name
 177                         source-buffer-name (cdr (assoc :session params)) impl))
 178               (full-body (org-babel-expand-body:scheme body params)))
 179          (org-babel-scheme-execute-with-geiser
 180           full-body                      ; code
 181           (string= result-type "output") ; output?
 182           impl                           ; implementation
 183           (and (not (string= session "none")) session))) ; session
 184        (org-babel-pick-name (cdr (assoc :colname-names params))
 185                             (cdr (assoc :colnames params)))
 186        (org-babel-pick-name (cdr (assoc :rowname-names params))
 187                             (cdr (assoc :rownames params)))))))
 188
 189 (provide 'ob-scheme)
 190
 191 ;;; ob-scheme.el ends here