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 ;; Version: 0.02
   9
  10 ;;; License:
  11
  12 ;; This program 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, or (at your option)
  15 ;; any later version.
  16 ;;
  17 ;; This program 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; see the file COPYING.  If not, write to the
  24 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  25 ;; Boston, MA 02110-1301, USA.
  26
  27 ;;; Commentary:
  28
  29 ;; Org-Babel support for evaluating Oz source code.
  30 ;;
  31 ;; Oz code is always send to the Oz Programming Environment (OPI), the
  32 ;; Emacs mode and compiler interface for Oz programs. Therefore, only
  33 ;; session mode is supported. In practice, non-session code blocks are
  34 ;; handled equally well by the session mode. However, only a single
  35 ;; session is supported. Consequently, the :session header argument is
  36 ;; ignored.
  37 ;;
  38 ;; The Org-babel header argument :results is interpreted as
  39 ;; follows. :results output requires the respective code block to be
  40 ;; an Oz statement and :results value requires an Oz
  41 ;; expression. Currently, results are only supported for expressions
  42 ;; (i.e. the result of :results output is always nil).
  43 ;;
  44 ;; Expression evaluation happens synchronously. Therefore there is an
  45 ;; additional header argument :wait-time <number>, which specifies the
  46 ;; maximum time to wait for the result of a given expression. nil
  47 ;; means to wait as long as it takes to get a result (potentially wait
  48 ;; forever).
  49 ;;
  50 ;; NOTE: Currently the copyright of this file may not be in a state to
  51 ;;       permit inclusion as core software into Emacs or Org-mode.
  52
  53 ;;; Requirements:
  54
  55 ;; - Mozart Programming System, the implementation of the Oz
  56 ;;   programming language (http://www.mozart-oz.org/), which includes
  57 ;;   the major mode mozart for editing Oz programs.
  58 ;;
  59 ;; - StartOzServer.oz which is located in the contrib/scripts
  60 ;;   directory of the Org-mode repository
  61
  62 ;;; TODO:
  63
  64 ;; - Decide: set communication to \\switch -threadedqueries?
  65 ;;
  66 ;; - Only start Oz compiler when required, e.g., load Org-babel only when needed?
  67 ;;
  68 ;; - Avoid synchronous evaluation to avoid blocking Emacs (complex
  69 ;;   Strasheela programs can take long to find a result..). In order
  70 ;;   to cleanly map code blocks to their associated results (which can
  71 ;;   arrive then in any order) I could use IDs
  72 ;;   (e.g. integers). However, how do I do concurrency in Emacs Lisp,
  73 ;;   and how can I define org-babel-execute:oz concurrently.
  74 ;;
  75 ;; - Expressions are rarely used in Oz at the top-level, and using
  76 ;;   them in documentation and Literate Programs will cause
  77 ;;   confusion. Idea: hide expression from reader and instead show
  78 ;;   them statement (e.g., MIDI output statement) and then include
  79 ;;   result in Org file. Implementation: for expressions (:results
  80 ;;   value) support an additional header argument that takes arbitrary
  81 ;;   Oz code. This code is not seen by the reader, but will be used
  82 ;;   for the actual expression at the end.  Alternative: feed all
  83 ;;   relevant code as statement (:results output), then add expression
  84 ;;   as extra code block which outputs, e.g., file name (so the file
  85 ;;   name must be accessible by global var), but the code of this
  86 ;;   extra codeblock is not seen.  Hm, in that case it might be even
  87 ;;   more easy to manually add this link to the Org file.
  88 ;;
  89
  90
  91 (require 'ob)
  92 ;;; major mode for editing Oz programs
  93 (require 'mozart)
  94
  95 ;;
  96 ;; Interface to communicate with Oz.
  97 ;; (1) For statements without any results: oz-send-string
  98 ;; (2) For expressions with a single result: oz-send-string-expression
  99 ;;     (defined in org-babel-oz-ResultsValue.el)
 100 ;;
 101
 102 ;; oz-send-string-expression implements an additional very direct
 103 ;; communication between Org-babel and the Oz compiler. Communication
 104 ;; with the Oz server works already without this code via the function
 105 ;; oz-send-string from mozart.el.in, but this function does not get
 106 ;; back any results from Oz to Emacs. The following code creates a
 107 ;; socket for sending code to the OPI compiler and results are
 108 ;; returned by the same socket. On the Oz side, a socket is opened and
 109 ;; conected to the compiler of the OPI (via oz-send-string). On the
 110 ;; Emacs side, a connection to this socket is created for feeding code
 111 ;; and receiving results. This additional communication channel to the
 112 ;; OPI compiler ensures that results are returned cleanly (e.g., only
 113 ;; the result of the sent code is returned, no parsing or any
 114 ;; processing of *Oz Emulator* is required).
 115 ;;
 116 ;; There is no buffer, nor sentinel involved. Oz code is send
 117 ;; directly, and results from Oz are send back, but Emacs Lisp
 118 ;; requires a filter function for processing results.
 119
 120 (defvar org-babel-oz-server-dir
 121   (file-name-as-directory
 122    (expand-file-name
 123     "contrib/scripts"
 124     (file-name-as-directory
 125      (expand-file-name
 126       "../../.."
 127       (file-name-directory (or load-file-name buffer-file-name))))))
 128   "Path to the contrib/scripts directory in which
 129 StartOzServer.oz is located.")
 130
 131 (defvar org-babel-oz-port 6001
 132   "Port for communicating with Oz compiler.")
 133 (defvar org-babel-oz-OPI-socket nil
 134   "Socket for communicating with OPI.")
 135
 136 (defvar org-babel-oz-collected-result nil
 137   "Aux var to hand result from org-babel-oz-filter to oz-send-string-expression.")
 138 (defun org-babel-oz-filter (proc string)
 139   "Processes output from socket org-babel-oz-OPI-socket."
 140 ;;   (setq org-babel-oz-collected-results (cons string org-babel-oz-collected-results))
 141   (setq org-babel-oz-collected-result string)
 142   )
 143
 144
 145 (defun org-babel-oz-create-socket ()
 146   (message "Create OPI socket for evaluating expressions")
 147   ;; Start Oz directly
 148   (run-oz)
 149   ;; Create socket on Oz side (after Oz was started).
 150   (oz-send-string (concat "\\insert '" org-babel-oz-server-dir "StartOzServer.oz'"))
 151   ;; Wait until socket is created before connecting to it.
 152   ;; Quick hack: wait 3 sec
 153   ;;
 154   ;; extending time to 30 secs does not help when starting Emacs for
 155   ;; the first time (and computer does nothing else)
 156   (sit-for 3)
 157   ;; connect to OPI socket
 158   (setq org-babel-oz-OPI-socket
 159         ;; Creates a socket. I/O interface of Emacs sockets as for processes.
 160         (open-network-stream "*Org-babel-OPI-socket*" nil "localhost" org-babel-oz-port))
 161   ;; install filter
 162   (set-process-filter org-babel-oz-OPI-socket #'org-babel-oz-filter)
 163 )
 164
 165 ;; communication with org-babel-oz-OPI-socket is asynchronous, but
 166 ;; oz-send-string-expression turns is into synchronous...
 167 (defun oz-send-string-expression (string &optional wait-time)
 168   "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."
 169   (if (not org-babel-oz-OPI-socket)
 170       (org-babel-oz-create-socket))
 171   (let ((polling-delay 0.1)
 172         result)
 173     (process-send-string org-babel-oz-OPI-socket string)
 174     ;; wait for result
 175     (if wait-time
 176         (let ((waited 0))
 177           (unwind-protect
 178               (progn
 179                 (while
 180                     ;; stop loop if org-babel-oz-collected-result \= nil or waiting time is over
 181                     (not (or (not (equal org-babel-oz-collected-result nil))
 182                              (> waited wait-time)))
 183                   (progn
 184                     (sit-for polling-delay)
 185 ;;                  (message "org-babel-oz: next polling iteration")
 186                     (setq waited (+ waited polling-delay))))
 187 ;;              (message "org-babel-oz: waiting over, got result or waiting timed out")
 188 ;;              (message (format "wait-time: %s, waited: %s" wait-time waited))
 189                 (setq result org-babel-oz-collected-result)
 190                 (setq org-babel-oz-collected-result nil))))
 191       (unwind-protect
 192           (progn
 193             (while (equal org-babel-oz-collected-result nil)
 194               (sit-for polling-delay))
 195             (setq result org-babel-oz-collected-result)
 196             (setq org-babel-oz-collected-result nil))))
 197     result))
 198
 199 (defun org-babel-expand-body:oz (body params)
 200   (let ((vars (mapcar #'cdr (org-babel-get-header params :var))))
 201     (if vars
 202         ;; prepend code to define all arguments passed to the code block
 203         (let ((var-string (mapcar (lambda (pair)
 204                                     (format "%s=%s"
 205                                             (car pair)
 206                                             (org-babel-oz-var-to-oz (cdr pair))))
 207                                   vars)))
 208           ;; only add var declarations if any variables are there
 209           (mapconcat #'identity
 210                      (append (list "local") var-string (list "in" body "end"))
 211                      "\n"))
 212       body)))
 213
 214 (defun org-babel-execute:oz (body params)
 215   "Execute a block of Oz code with org-babel.  This function is
 216 called by `org-babel-execute-src-block' via multiple-value-bind."
 217   (let* ((result-params (cdr (assoc :result-params params)))
 218          (full-body (org-babel-expand-body:oz body params))
 219          (wait-time (plist-get params :wait-time)))
 220     ;; actually execute the source-code block
 221     (org-babel-reassemble-table
 222      (cond
 223       ((member "output" result-params)
 224        (message "Org-babel: executing Oz statement")
 225        (oz-send-string full-body))
 226       ((member "value" result-params)
 227        (message "Org-babel: executing Oz expression")
 228        (oz-send-string-expression full-body (or wait-time 1)))
 229       (t (error "either 'output' or 'results' must be members of :results.")))
 230      (org-babel-pick-name (cdr (assoc :colname-names params))
 231                           (cdr (assoc :colnames params)))
 232      (org-babel-pick-name (cdr (assoc :roname-names params))
 233                           (cdr (assoc :rownames params))))))
 234
 235 ;; This function should be used to assign any variables in params in
 236 ;; the context of the session environment.
 237 (defun org-babel-prep-session:oz (session params)
 238   "Prepare SESSION according to the header arguments specified in PARAMS."
 239   (error "org-babel-prep-session:oz unimplemented"))
 240 ;; TODO: testing... (copied from org-babel-haskell.el)
 241 ;; (defun org-babel-prep-session:oz (session params)
 242 ;;   "Prepare SESSION according to the header arguments specified in PARAMS."
 243 ;;   (save-window-excursion
 244 ;;     (org-babel-oz-initiate-session session)
 245 ;;     (let* ((vars (org-babel-ref-variables params))
 246 ;;            (var-lines (mapconcat ;; define any variables
 247 ;;                        (lambda (pair)
 248 ;;                          (format "%s=%s"
 249 ;;                                  (car pair)
 250 ;;                                  (org-babel-ruby-var-to-ruby (cdr pair))))
 251 ;;                        vars "\n"))
 252 ;;            (vars-file (concat (make-temp-file "org-babel-oz-vars") ".oz")))
 253 ;;       (when vars
 254 ;;         (with-temp-buffer
 255 ;;           (insert var-lines) (write-file vars-file)
 256 ;;           (oz-mode)
 257 ;; ;;     (inferior-oz-load-file) ; ??
 258 ;;        ))
 259 ;;       (current-buffer))))
 260 ;;
 261
 262
 263 ;; TODO: testing... (simplified version of def in org-babel-prep-session:ocaml)
 264 ;;
 265 ;; BUG: does not work yet. Error: ad-Orig-error: buffer none doesn't exist or has no process
 266 ;; UNUSED DEF
 267 (defun org-babel-oz-initiate-session (&optional session params)
 268   "If there is not a current inferior-process-buffer in SESSION
 269 then create.  Return the initialized session."
 270   (unless (string= session "none")
 271     ;; TODO: make it possible to have multiple sessions
 272     (save-window-excursion
 273       ;; (run-oz)
 274       (get-buffer oz-compiler-buffer))))
 275
 276 (defun org-babel-oz-var-to-oz (var)
 277   "Convert an elisp var into a string of Oz source code
 278 specifying a var of the same value."
 279   (if (listp var)
 280 ;;       (concat "[" (mapconcat #'org-babel-oz-var-to-oz var ", ") "]")
 281       (eval var)
 282     (format "%s" var) ; don't preserve string quotes.
 283 ;;     (format "%s" var)
 284     ))
 285
 286 ;; TODO:
 287 (defun org-babel-oz-table-or-string (results)
 288   "If the results look like a table, then convert them into an
 289 Emacs-lisp table, otherwise return the results as a string."
 290   (error "org-babel-oz-table-or-string unimplemented"))
 291
 292
 293 (provide 'ob-oz)
 294 ;;; org-babel-oz.el ends here