lisp/ob-scheme.el

   1 ;;; ob-scheme.el --- Babel Functions for Scheme      -*- lexical-binding: t; -*-
   2
   3 ;; Copyright (C) 2010-2017 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 (defcustom org-babel-scheme-null-to 'hline
  55   "Replace `null' and empty lists in scheme tables with this before returning."
  56   :group 'org-babel
  57   :version "26.1"
  58   :package-version '(Org . "9.1")
  59   :type 'symbol)
  60
  61 (defvar org-babel-default-header-args:scheme '()
  62   "Default header arguments for scheme code blocks.")
  63
  64 (defun org-babel-expand-body:scheme (body params)
  65   "Expand BODY according to PARAMS, return the expanded body."
  66   (let ((vars (org-babel--get-vars params))
  67         (prepends (cdr (assq :prologue params))))
  68     (concat (and prepends (concat prepends "\n"))
  69             (if (null vars) body
  70               (format "(let (%s)\n%s\n)"
  71                       (mapconcat
  72                        (lambda (var)
  73                          (format "%S" (print `(,(car var) ',(cdr var)))))
  74                        vars
  75                        "\n      ")
  76                       body)))))
  77
  78
  79 (defvar org-babel-scheme-repl-map (make-hash-table :test #'equal)
  80   "Map of scheme sessions to session names.")
  81
  82 (defun org-babel-scheme-cleanse-repl-map ()
  83   "Remove dead buffers from the REPL map."
  84   (maphash
  85    (lambda (x y) (unless (buffer-name y) (remhash x org-babel-scheme-repl-map)))
  86    org-babel-scheme-repl-map))
  87
  88 (defun org-babel-scheme-get-session-buffer (session-name)
  89   "Look up the scheme buffer for a session; return nil if it doesn't exist."
  90   (org-babel-scheme-cleanse-repl-map) ; Prune dead sessions
  91   (gethash session-name org-babel-scheme-repl-map))
  92
  93 (defun org-babel-scheme-set-session-buffer (session-name buffer)
  94   "Record the scheme buffer used for a given session."
  95   (puthash session-name buffer org-babel-scheme-repl-map))
  96
  97 (defun org-babel-scheme-get-buffer-impl (buffer)
  98   "Returns the scheme implementation geiser associates with the buffer."
  99   (with-current-buffer (set-buffer buffer)
 100     geiser-impl--implementation))
 101
 102 (defun org-babel-scheme-get-repl (impl name)
 103   "Switch to a scheme REPL, creating it if it doesn't exist:"
 104   (let ((buffer (org-babel-scheme-get-session-buffer name)))
 105     (or buffer
 106         (progn
 107           (run-geiser impl)
 108           (if name
 109               (progn
 110                 (rename-buffer name t)
 111                 (org-babel-scheme-set-session-buffer name (current-buffer))))
 112           (current-buffer)))))
 113
 114 (defun org-babel-scheme-make-session-name (buffer name impl)
 115   "Generate a name for the session buffer.
 116
 117 For a named session, the buffer name will be the session name.
 118
 119 If the session is unnamed (nil), generate a name.
 120
 121 If the session is `none', use nil for the session name, and
 122 org-babel-scheme-execute-with-geiser will use a temporary session."
 123   (cond ((not name) (concat buffer " " (symbol-name impl) " REPL"))
 124         ((string= name "none") nil)
 125         (name)))
 126
 127 (defmacro org-babel-scheme-capture-current-message (&rest body)
 128   "Capture current message in both interactive and noninteractive mode"
 129   `(if noninteractive
 130        (let ((original-message (symbol-function 'message))
 131              (current-message nil))
 132          (unwind-protect
 133              (progn
 134                (defun message (&rest args)
 135                  (setq current-message (apply original-message args)))
 136                ,@body
 137                current-message)
 138            (fset 'message original-message)))
 139      (progn
 140        ,@body
 141        (current-message))))
 142
 143 (defun org-babel-scheme-execute-with-geiser (code output impl repl)
 144   "Execute code in specified REPL. If the REPL doesn't exist, create it
 145 using the given scheme implementation.
 146
 147 Returns the output of executing the code if the output parameter
 148 is true; otherwise returns the last value."
 149   (let ((result nil))
 150     (with-temp-buffer
 151       (insert (format ";; -*- geiser-scheme-implementation: %s -*-" impl))
 152       (newline)
 153       (insert (if output
 154                   (format "(with-output-to-string (lambda () %s))" code)
 155                 code))
 156       (geiser-mode)
 157       (let ((repl-buffer (save-current-buffer
 158                            (org-babel-scheme-get-repl impl repl))))
 159         (when (not (eq impl (org-babel-scheme-get-buffer-impl
 160                              (current-buffer))))
 161           (message "Implementation mismatch: %s (%s) %s (%s)" impl (symbolp impl)
 162                    (org-babel-scheme-get-buffer-impl (current-buffer))
 163                    (symbolp (org-babel-scheme-get-buffer-impl
 164                              (current-buffer)))))
 165         (setq geiser-repl--repl repl-buffer)
 166         (setq geiser-impl--implementation nil)
 167         (setq result (org-babel-scheme-capture-current-message
 168                       (geiser-eval-region (point-min) (point-max))))
 169         (setq result
 170               (if (and (stringp result) (equal (substring result 0 3) "=> "))
 171                   (replace-regexp-in-string "^=> " "" result)
 172                 "\"An error occurred.\""))
 173         (when (not repl)
 174           (save-current-buffer (set-buffer repl-buffer)
 175                                (geiser-repl-exit))
 176           (set-process-query-on-exit-flag (get-buffer-process repl-buffer) nil)
 177           (kill-buffer repl-buffer))
 178         (setq result (if (or (string= result "#<void>")
 179                              (string= result "#<unspecified>"))
 180                          nil
 181                        result))))
 182     result))
 183
 184 (defun org-babel-scheme--table-or-string (results)
 185   "Convert RESULTS into an appropriate elisp value.
 186 If the results look like a list or tuple, then convert them into an
 187 Emacs-lisp table, otherwise return the results as a string."
 188   (let ((res (org-babel-script-escape results)))
 189     (cond ((listp res)
 190            (mapcar (lambda (el)
 191                      (if (or (null el) (eq el 'null))
 192                          org-babel-scheme-null-to
 193                        el))
 194                    res))
 195           (t res))))
 196
 197 (defun org-babel-execute:scheme (body params)
 198   "Execute a block of Scheme code with org-babel.
 199 This function is called by `org-babel-execute-src-block'"
 200   (let* ((source-buffer (current-buffer))
 201          (source-buffer-name (replace-regexp-in-string ;; zap surrounding *
 202                               "^ ?\\*\\([^*]+\\)\\*" "\\1"
 203                               (buffer-name source-buffer))))
 204     (save-excursion
 205       (let* ((result-type (cdr (assq :result-type params)))
 206              (impl (or (when (cdr (assq :scheme params))
 207                          (intern (cdr (assq :scheme params))))
 208                        geiser-default-implementation
 209                        (car geiser-active-implementations)))
 210              (session (org-babel-scheme-make-session-name
 211                        source-buffer-name (cdr (assq :session params)) impl))
 212              (full-body (org-babel-expand-body:scheme body params))
 213              (result
 214               (org-babel-scheme-execute-with-geiser
 215                full-body                       ; code
 216                (string= result-type "output")  ; output?
 217                impl                            ; implementation
 218                (and (not (string= session "none")) session)))) ; session
 219         (let ((table
 220                (org-babel-reassemble-table
 221                 result
 222                 (org-babel-pick-name (cdr (assq :colname-names params))
 223                                      (cdr (assq :colnames params)))
 224                 (org-babel-pick-name (cdr (assq :rowname-names params))
 225                                      (cdr (assq :rownames params))))))
 226           (org-babel-scheme--table-or-string table))))))
 227
 228 (provide 'ob-scheme)
 229
 230 ;;; ob-scheme.el ends here