contrib/babel/langs/ob-oz.el

   1 ;;; ob-oz.el --- org-babel functions for Oz evaluation
   2
   3 ;; Copyright (C) 2009, 2012 Torsten Anders and Eric Schulte
   4
   5 ;; Author: Torsten Anders and Eric Schulte
   6 ;; Keywords: literate programming, reproducible research
   7 ;; Homepage: http://orgmode.org
   8
   9 ;;; License:
  10
  11 ;; This program is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 3, or (at your option)
  14 ;; any later version.
  15 ;;
  16 ;; This program is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20 ;;
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  24 ;; Boston, MA 02110-1301, USA.
  25
  26 ;;; Commentary:
  27
  28 ;; Org-Babel support for evaluating Oz source code.
  29 ;;
  30 ;; Oz code is always send to the Oz Programming Environment (OPI), the
  31 ;; Emacs mode and compiler interface for Oz programs. Therefore, only
  32 ;; session mode is supported. In practice, non-session code blocks are
  33 ;; handled equally well by the session mode. However, only a single
  34 ;; session is supported. Consequently, the :session header argument is
  35 ;; ignored.
  36 ;;
  37 ;; The Org-babel header argument :results is interpreted as
  38 ;; follows. :results output requires the respective code block to be
  39 ;; an Oz statement and :results value requires an Oz
  40 ;; expression. Currently, results are only supported for expressions
  41 ;; (i.e. the result of :results output is always nil).
  42 ;;
  43 ;; Expression evaluation happens synchronously. Therefore there is an
  44 ;; additional header argument :wait-time <number>, which specifies the
  45 ;; maximum time to wait for the result of a given expression. nil
  46 ;; means to wait as long as it takes to get a result (potentially wait
  47 ;; forever).
  48 ;;
  49 ;; NOTE: Currently the copyright of this file may not be in a state to
  50 ;;       permit inclusion as core software into Emacs or Org-mode.
  51
  52 ;;; Requirements:
  53
  54 ;; - Mozart Programming System, the implementation of the Oz
  55 ;;   programming language (http://www.mozart-oz.org/), which includes
  56 ;;   the major mode mozart for editing Oz programs.
  57 ;;
  58 ;; - StartOzServer.oz which is located in the contrib/scripts
  59 ;;   directory of the Org-mode repository
  60
  61 ;;; TODO:
  62
  63 ;; - Decide: set communication to \\switch -threadedqueries?
  64 ;;
  65 ;; - Only start Oz compiler when required, e.g., load Org-babel only when needed?
  66 ;;
  67 ;; - Avoid synchronous evaluation to avoid blocking Emacs (complex
  68 ;;   Strasheela programs can take long to find a result..). In order
  69 ;;   to cleanly map code blocks to their associated results (which can
  70 ;;   arrive then in any order) I could use IDs
  71 ;;   (e.g. integers). However, how do I do concurrency in Emacs Lisp,
  72 ;;   and how can I define org-babel-execute:oz concurrently.
  73 ;;
  74 ;; - Expressions are rarely used in Oz at the top-level, and using
  75 ;;   them in documentation and Literate Programs will cause
  76 ;;   confusion. Idea: hide expression from reader and instead show
  77 ;;   them statement (e.g., MIDI output statement) and then include
  78 ;;   result in Org file. Implementation: for expressions (:results
  79 ;;   value) support an additional header argument that takes arbitrary
  80 ;;   Oz code. This code is not seen by the reader, but will be used
  81 ;;   for the actual expression at the end.  Alternative: feed all
  82 ;;   relevant code as statement (:results output), then add expression
  83 ;;   as extra code block which outputs, e.g., file name (so the file
  84 ;;   name must be accessible by global var), but the code of this
  85 ;;   extra codeblock is not seen.  Hm, in that case it might be even
  86 ;;   more easy to manually add this link to the Org file.
  87 ;;
  88
  89
  90 (require 'ob)
  91 ;;; major mode for editing Oz programs
  92 (require 'mozart)
  93
  94 ;;
  95 ;; Interface to communicate with Oz.
  96 ;; (1) For statements without any results: oz-send-string
  97 ;; (2) For expressions with a single result: oz-send-string-expression
  98 ;;     (defined in org-babel-oz-ResultsValue.el)
  99 ;;
 100
 101 ;; oz-send-string-expression implements an additional very direct
 102 ;; communication between Org-babel and the Oz compiler. Communication
 103 ;; with the Oz server works already without this code via the function
 104 ;; oz-send-string from mozart.el.in, but this function does not get
 105 ;; back any results from Oz to Emacs. The following code creates a
 106 ;; socket for sending code to the OPI compiler and results are
 107 ;; returned by the same socket. On the Oz side, a socket is opened and
 108 ;; conected to the compiler of the OPI (via oz-send-string). On the
 109 ;; Emacs side, a connection to this socket is created for feeding code
 110 ;; and receiving results. This additional communication channel to the
 111 ;; OPI compiler ensures that results are returned cleanly (e.g., only
 112 ;; the result of the sent code is returned, no parsing or any
 113 ;; processing of *Oz Emulator* is required).
 114 ;;
 115 ;; There is no buffer, nor sentinel involved. Oz code is send
 116 ;; directly, and results from Oz are send back, but Emacs Lisp
 117 ;; requires a filter function for processing results.
 118
 119 (defvar org-babel-oz-server-dir
 120   (file-name-as-directory
 121    (expand-file-name
 122     "contrib/scripts"
 123     (file-name-as-directory
 124      (expand-file-name
 125       "../../.."
 126       (file-name-directory (or load-file-name buffer-file-name))))))
 127   "Path to the contrib/scripts directory in which
 128 StartOzServer.oz is located.")
 129
 130 (defvar org-babel-oz-port 6001
 131   "Port for communicating with Oz compiler.")
 132 (defvar org-babel-oz-OPI-socket nil
 133   "Socket for communicating with OPI.")
 134
 135 (defvar org-babel-oz-collected-result nil
 136   "Aux var to hand result from org-babel-oz-filter to oz-send-string-expression.")
 137 (defun org-babel-oz-filter (proc string)
 138   "Processes output from socket org-babel-oz-OPI-socket."
 139 ;;   (setq org-babel-oz-collected-results (cons string org-babel-oz-collected-results))
 140   (setq org-babel-oz-collected-result string)
 141   )
 142
 143
 144 (defun org-babel-oz-create-socket ()
 145   (message "Create OPI socket for evaluating expressions")
 146   ;; Start Oz directly
 147   (run-oz)
 148   ;; Create socket on Oz side (after Oz was started).
 149   (oz-send-string (concat "\\insert '" org-babel-oz-server-dir "StartOzServer.oz'"))
 150   ;; Wait until socket is created before connecting to it.
 151   ;; Quick hack: wait 3 sec
 152   ;;
 153   ;; extending time to 30 secs does not help when starting Emacs for
 154   ;; the first time (and computer does nothing else)
 155   (sit-for 3)
 156   ;; connect to OPI socket
 157   (setq org-babel-oz-OPI-socket
 158         ;; Creates a socket. I/O interface of Emacs sockets as for processes.
 159         (open-network-stream "*Org-babel-OPI-socket*" nil "localhost" org-babel-oz-port))
 160   ;; install filter
 161   (set-process-filter org-babel-oz-OPI-socket #'org-babel-oz-filter)
 162 )
 163
 164 ;; communication with org-babel-oz-OPI-socket is asynchronous, but
 165 ;; oz-send-string-expression turns is into synchronous...
 166 (defun oz-send-string-expression (string &optional wait-time)
 167   "Similar to oz-send-string, oz-send-string-expression sends a string to the OPI compiler. However, string must be expression and this function returns the result of the expression (as string). oz-send-string-expression is synchronous, wait-time allows to specify a maximum wait time. After wait-time is over with no result, the function returns nil."
 168   (if (not org-babel-oz-OPI-socket)
 169       (org-babel-oz-create-socket))
 170   (let ((polling-delay 0.1)
 171         result)
 172     (process-send-string org-babel-oz-OPI-socket string)
 173     ;; wait for result
 174     (if wait-time
 175         (let ((waited 0))
 176           (unwind-protect
 177               (progn
 178                 (while
 179                     ;; stop loop if org-babel-oz-collected-result \= nil or waiting time is over
 180                     (not (or (not (equal org-babel-oz-collected-result nil))
 181                              (> waited wait-time)))
 182                   (progn
 183                     (sit-for polling-delay)
 184 ;;                  (message "org-babel-oz: next polling iteration")
 185                     (setq waited (+ waited polling-delay))))
 186 ;;              (message "org-babel-oz: waiting over, got result or waiting timed out")
 187 ;;              (message (format "wait-time: %s, waited: %s" wait-time waited))
 188                 (setq result org-babel-oz-collected-result)
 189                 (setq org-babel-oz-collected-result nil))))
 190       (unwind-protect
 191           (progn
 192             (while (equal org-babel-oz-collected-result nil)
 193               (sit-for polling-delay))
 194             (setq result org-babel-oz-collected-result)
 195             (setq org-babel-oz-collected-result nil))))
 196     result))
 197
 198 (defun org-babel-expand-body:oz (body params)
 199   (let ((vars (mapcar #'cdr (org-babel-get-header params :var))))
 200     (if vars
 201         ;; prepend code to define all arguments passed to the code block
 202         (let ((var-string (mapcar (lambda (pair)
 203                                     (format "%s=%s"
 204                                             (car pair)
 205                                             (org-babel-oz-var-to-oz (cdr pair))))
 206                                   vars)))
 207           ;; only add var declarations if any variables are there
 208           (mapconcat #'identity
 209                      (append (list "local") var-string (list "in" body "end"))
 210                      "\n"))
 211       body)))
 212
 213 (defun org-babel-execute:oz (body params)
 214   "Execute a block of Oz code with org-babel.  This function is
 215 called by `org-babel-execute-src-block' via multiple-value-bind."
 216   (let* ((result-params (cdr (assoc :result-params params)))
 217          (full-body (org-babel-expand-body:oz body params))
 218          (wait-time (plist-get params :wait-time)))
 219     ;; actually execute the source-code block
 220     (org-babel-reassemble-table
 221      (cond
 222       ((member "output" result-params)
 223        (message "Org-babel: executing Oz statement")
 224        (oz-send-string full-body))
 225       ((member "value" result-params)
 226        (message "Org-babel: executing Oz expression")
 227        (oz-send-string-expression full-body (or wait-time 1)))
 228       (t (error "either 'output' or 'results' must be members of :results.")))
 229      (org-babel-pick-name (cdr (assoc :colname-names params))
 230                           (cdr (assoc :colnames params)))
 231      (org-babel-pick-name (cdr (assoc :roname-names params))
 232                           (cdr (assoc :rownames params))))))
 233
 234 ;; This function should be used to assign any variables in params in
 235 ;; the context of the session environment.
 236 (defun org-babel-prep-session:oz (session params)
 237   "Prepare SESSION according to the header arguments specified in PARAMS."
 238   (error "org-babel-prep-session:oz unimplemented"))
 239 ;; TODO: testing... (copied from org-babel-haskell.el)
 240 ;; (defun org-babel-prep-session:oz (session params)
 241 ;;   "Prepare SESSION according to the header arguments specified in PARAMS."
 242 ;;   (save-window-excursion
 243 ;;     (org-babel-oz-initiate-session session)
 244 ;;     (let* ((vars (org-babel-ref-variables params))
 245 ;;            (var-lines (mapconcat ;; define any variables
 246 ;;                        (lambda (pair)
 247 ;;                          (format "%s=%s"
 248 ;;                                  (car pair)
 249 ;;                                  (org-babel-ruby-var-to-ruby (cdr pair))))
 250 ;;                        vars "\n"))
 251 ;;            (vars-file (concat (make-temp-file "org-babel-oz-vars") ".oz")))
 252 ;;       (when vars
 253 ;;         (with-temp-buffer
 254 ;;           (insert var-lines) (write-file vars-file)
 255 ;;           (oz-mode)
 256 ;; ;;     (inferior-oz-load-file) ; ??
 257 ;;        ))
 258 ;;       (current-buffer))))
 259 ;;
 260
 261
 262 ;; TODO: testing... (simplified version of def in org-babel-prep-session:ocaml)
 263 ;;
 264 ;; BUG: does not work yet. Error: ad-Orig-error: buffer none doesn't exist or has no process
 265 ;; UNUSED DEF
 266 (defun org-babel-oz-initiate-session (&optional session params)
 267   "If there is not a current inferior-process-buffer in SESSION
 268 then create.  Return the initialized session."
 269   (unless (string= session "none")
 270     ;; TODO: make it possible to have multiple sessions
 271     (save-window-excursion
 272       ;; (run-oz)
 273       (get-buffer oz-compiler-buffer))))
 274
 275 (defun org-babel-oz-var-to-oz (var)
 276   "Convert an elisp var into a string of Oz source code
 277 specifying a var of the same value."
 278   (if (listp var)
 279 ;;       (concat "[" (mapconcat #'org-babel-oz-var-to-oz var ", ") "]")
 280       (eval var)
 281     (format "%s" var) ; don't preserve string quotes.
 282 ;;     (format "%s" var)
 283     ))
 284
 285 ;; TODO:
 286 (defun org-babel-oz-table-or-string (results)
 287   "If the results look like a table, then convert them into an
 288 Emacs-lisp table, otherwise return the results as a string."
 289   (error "org-babel-oz-table-or-string unimplemented"))
 290
 291
 292 (provide 'ob-oz)
 293 ;;; org-babel-oz.el ends here