;;; ob-io.el --- org-babel functions for Io evaluation

;; Copyright (C) Andrzej Lichnerowicz

;; Author: Andrzej Lichnerowicz
;; Keywords: literate programming, reproducible research
;; Homepage: http://orgmode.org
;; Version: 0.01

;;; License:

;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 3, or (at your option)
;; any later version.
;;
;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.
;;
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Commentary:
;; Currently only supports the external execution. No session support yet.
;; :results output -- runs in scripting mode
;; :results output repl -- runs in repl mode

;;; Requirements:
;; - Io language :: http://iolanguage.org/
;; - Io major mode :: Can be installed from Io sources
;;  https://github.com/stevedekorte/io/blob/master/extras/SyntaxHighlighters/Emacs/io-mode.el


;;; Code:
(require 'ob)
(require 'ob-ref)
(require 'ob-comint)
(require 'ob-eval)

(add-to-list 'org-babel-tangle-lang-exts '("io" . "io"))
(defvar org-babel-default-header-args:io '())
(defvar org-babel-io-command "io"
  "Name of the command to use for executing Io code.")


(defun org-babel-execute:io (body params)
  "Execute a block of Io code with org-babel.  This function is
called by `org-babel-execute-src-block'"
  (message "executing Io source code block")
  (let* ((processed-params (org-babel-process-params params))
         (session (org-babel-io-initiate-session (first processed-params)))
         (vars (second processed-params))
         (result-params (third processed-params))
         (result-type (cdr (assoc :result-type params)))
         (full-body (org-babel-expand-body:generic
                     body params))
         (result (org-babel-io-evaluate
                  session full-body result-type result-params)))

    (org-babel-reassemble-table
     result
     (org-babel-pick-name
      (cdr (assoc :colname-names params)) (cdr (assoc :colnames params)))
     (org-babel-pick-name
      (cdr (assoc :rowname-names params)) (cdr (assoc :rownames params))))))


(defun org-babel-io-evaluate (session body &optional result-type result-params)
  "Evaluate BODY in external Io process.
If RESULT-TYPE equals 'output then return standard output as a string.
If RESULT-TYPE equals 'value then return the value of the last statement
in BODY as elisp."
  (when session (error "Sessions are not supported for Io. Yet."))
  (case result-type
    (output 
     (if (member "repl" result-params)
         (org-babel-eval org-babel-io-command body) 
       (let ((src-file (org-babel-temp-file "io-")))
         (progn (with-temp-file src-file (insert full-body))
                (org-babel-eval
                 (concat org-babel-io-command " " src-file) "")))))
    (value (error "Value result type is not supported for Io. Yet."))))

(defun org-babel-prep-session:io (session params)
  "Prepare SESSION according to the header arguments specified in PARAMS."
  (error "Sessions are not supported for Io. Yet."))

(defun org-babel-io-initiate-session (&optional session)
  "If there is not a current inferior-process-buffer in SESSION
then create.  Return the initialized session. Sessions are not 
supported in Io."
  nil)

(provide 'ob-io)
;;; ob-io.el ends here