Re: [O] ob-lua

[Thibault Marin]

>From bd6e5cf8e11fc87b0e4219b7378d43ddf69de7f1 Mon Sep 17 00:00:00 2001
From: thibault <address@hidden>
Date: Sun, 21 Aug 2016 20:43:37 -0500
Subject: [PATCH] ob-lua.el: Add lua support to org-babel

* contrib/lisp/ob-lua.el: Resurrect ob-lua.el from
https://lists.gnu.org/archive/html/emacs-orgmode/2014-05/msg01149.html,
replace deprecated functions `org-babel-get-header' and
`org-babel-trim' by `org-babel--get-vars' and `org-trim'
respectively.  Sessions are not supported.

* testing/test-ob-lua.el: Testing for ob-lua.el.  Test table
variable passing and results with `value' and `output' options.
---
 contrib/lisp/ob-lua.el      | 405 ++++++++++++++++++++++++++++++++++++++++++++
 testing/lisp/test-ob-lua.el | 141 +++++++++++++++
 2 files changed, 546 insertions(+)
 create mode 100644 contrib/lisp/ob-lua.el
 create mode 100644 testing/lisp/test-ob-lua.el

diff --git a/contrib/lisp/ob-lua.el b/contrib/lisp/ob-lua.el
new file mode 100644
index 0000000..a81ec66
--- /dev/null
+++ b/contrib/lisp/ob-lua.el
@@ -0,0 +1,405 @@
+;;; ob-lua.el --- org-babel functions for lua evaluation
+
+;; Copyright (C) 2009-2014 Free Software Foundation, Inc.
+
+;; Authors: Dieter Schoen
+;;      Eric Schulte, Dan Davison
+;; Keywords: literate programming, reproducible research
+;; Homepage: http://orgmode.org
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs 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 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs 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.  If not, see <http://www.gnu.org/licenses/>.
+
+;; Requirements:
+;; for session support, lua-mode is needed.
+;; lua-mode is not part of GNU Emacs/orgmode, but can be obtained
+;; from marmalade or melpa.
+;; The source respository is here:
+;; https://github.com/immerrr/lua-mode
+
+;; However, sessions are not yet working.
+
+;; Org-Babel support for evaluating lua source code.
+
+;;; Code:
+(require 'ob)
+(eval-when-compile (require 'cl))
+
+(declare-function org-remove-indentation "org" )
+(declare-function lua-shell "ext:lua-mode" (&optional argprompt))
+(declare-function lua-toggle-shells "ext:lua-mode" (arg))
+(declare-function run-lua "ext:lua" (cmd &optional dedicated show))
+
+(defvar org-babel-tangle-lang-exts)
+(add-to-list 'org-babel-tangle-lang-exts '("lua" . "lua"))
+
+(defvar org-babel-default-header-args:lua '())
+
+(defcustom org-babel-lua-command "lua"
+  "Name of the command for executing Lua code."
+  :version "24.5"
+  :package-version '(Org . "8.3")
+  :group 'org-babel
+  :type 'string)
+
+(defcustom org-babel-lua-mode 'lua-mode
+  "Preferred lua mode for use in running lua interactively.
+This will typically be 'lua-mode."
+  :group 'org-babel
+  :version "24.5"
+  :package-version '(Org . "8.3")
+  :type 'symbol)
+
+(defcustom org-babel-lua-hline-to "None"
+  "Replace hlines in incoming tables with this when translating to lua."
+  :group 'org-babel
+  :version "24.5"
+  :package-version '(Org . "8.3")
+  :type 'string)
+
+(defcustom org-babel-lua-None-to 'hline
+  "Replace 'None' in lua tables with this before returning."
+  :group 'org-babel
+  :version "24.5"
+  :package-version '(Org . "8.3")
+  :type 'symbol)
+
+(defun org-babel-execute:lua (body params)
+  "Execute a block of Lua code with Babel.
+This function is called by `org-babel-execute-src-block'."
+  (let* ((session (org-babel-lua-initiate-session
+                  (cdr (assoc :session params))))
+         (result-params (cdr (assoc :result-params params)))
+         (result-type (cdr (assoc :result-type params)))
+        (return-val (when (and (eq result-type 'value) (not session))
+                      (cdr (assoc :return params))))
+        (preamble (cdr (assoc :preamble params)))
+         (full-body
+         (org-babel-expand-body:generic
+          (concat body (if return-val (format "\nreturn %s" return-val) ""))
+          params (org-babel-variable-assignments:lua params)))
+         (result (org-babel-lua-evaluate
+                 session full-body result-type result-params preamble)))
+    (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-prep-session:lua (session params)
+  "Prepare SESSION according to the header arguments in PARAMS.
+VARS contains resolved variable references"
+  (let* ((session (org-babel-lua-initiate-session session))
+        (var-lines
+         (org-babel-variable-assignments:lua params)))
+    (org-babel-comint-in-buffer session
+      (mapc (lambda (var)
+              (end-of-line 1) (insert var) (comint-send-input)
+              (org-babel-comint-wait-for-output session)) var-lines))
+    session))
+
+(defun org-babel-load-session:lua (session body params)
+  "Load BODY into SESSION."
+  (save-window-excursion
+    (let ((buffer (org-babel-prep-session:lua session params)))
+      (with-current-buffer buffer
+        (goto-char (process-mark (get-buffer-process (current-buffer))))
+        (insert (org-babel-chomp body)))
+      buffer)))
+
+;; helper functions
+
+(defun org-babel-variable-assignments:lua (params)
+  "Return a list of Lua statements assigning the block's variables."
+  (mapcar
+   (lambda (pair)
+     (format "%s=%s"
+            (car pair)
+            (org-babel-lua-var-to-lua (cdr pair))))
+   (org-babel--get-vars params)))
+
+(defun org-babel-lua-var-to-lua (var)
+  "Convert an elisp value to a lua variable.
+Convert an elisp value, VAR, into a string of lua source code
+specifying a variable of the same value."
+  (if (listp var)
+      (if (and (= 1 (length var)) (not (listp (car var))))
+          (org-babel-lua-var-to-lua (car var))
+        (if (and
+             (= 2 (length var))
+             (not (listp (car var))))
+            (concat
+             (substring-no-properties (car var))
+             "="
+             (org-babel-lua-var-to-lua (cdr var)))
+          (concat "{" (mapconcat #'org-babel-lua-var-to-lua var ", ") "}")))
+    (if (equal var 'hline)
+        org-babel-lua-hline-to
+      (format
+       (if (and (stringp var) (string-match "[\n\r]" var)) "\"\"%S\"\"" "%S")
+       (if (stringp var) (substring-no-properties var) var)))))
+
+(defun org-babel-lua-table-or-string (results)
+  "Convert RESULTS into an appropriate elisp value.
+If the results look like a list or tuple, then convert them into an
+Emacs-lisp table, otherwise return the results as a string."
+  (let ((res (org-babel-script-escape results)))
+    (if (listp res)
+        (mapcar (lambda (el) (if (equal el 'None)
+                            org-babel-lua-None-to el))
+                res)
+      res)))
+
+(defvar org-babel-lua-buffers '((:default . "*Lua*")))
+
+(defun org-babel-lua-session-buffer (session)
+  "Return the buffer associated with SESSION."
+  (cdr (assoc session org-babel-lua-buffers)))
+
+(defun org-babel-lua-with-earmuffs (session)
+  (let ((name (if (stringp session) session (format "%s" session))))
+    (if (and (string= "*" (substring name 0 1))
+            (string= "*" (substring name (- (length name) 1))))
+       name
+      (format "*%s*" name))))
+
+(defun org-babel-lua-without-earmuffs (session)
+  (let ((name (if (stringp session) session (format "%s" session))))
+    (if (and (string= "*" (substring name 0 1))
+            (string= "*" (substring name (- (length name) 1))))
+       (substring name 1 (- (length name) 1))
+      name)))
+
+(defvar lua-default-interpreter)
+(defvar lua-which-bufname)
+(defvar lua-shell-buffer-name)
+(defun org-babel-lua-initiate-session-by-key (&optional session)
+  "Initiate a lua session.
+If there is not a current inferior-process-buffer in SESSION
+then create.  Return the initialized session."
+  (require org-babel-lua-mode)
+  (save-window-excursion
+    (let* ((session (if session (intern session) :default))
+           (lua-buffer (org-babel-lua-session-buffer session))
+          (cmd (if (member system-type '(cygwin windows-nt ms-dos))
+                   (concat org-babel-lua-command " -i")
+                 org-babel-lua-command)))
+      (cond
+       ((and (eq 'lua-mode org-babel-lua-mode)
+             (fboundp 'lua-start-process)) ; lua-mode.el
+        ;; Make sure that lua-which-bufname is initialized, as otherwise
+        ;; it will be overwritten the first time a Lua buffer is
+        ;; created.
+        ;;(lua-toggle-shells lua-default-interpreter)
+        ;; `lua-shell' creates a buffer whose name is the value of
+        ;; `lua-which-bufname' with '*'s at the beginning and end
+        (let* ((bufname (if (and lua-process-buffer
+                                 (buffer-live-p lua-process-buffer))
+                            (replace-regexp-in-string ;; zap surrounding *
+                             "^\\*\\([^*]+\\)\\*$" "\\1" (buffer-name 
lua-process-buffer))
+                          (concat "Lua-" (symbol-name session))))
+               (lua-which-bufname bufname))
+          (lua-start-process)
+          (setq lua-buffer (org-babel-lua-with-earmuffs bufname))))
+       (t
+       (error "No function available for running an inferior Lua")))
+      (setq org-babel-lua-buffers
+            (cons (cons session lua-process-buffer)
+                  (assq-delete-all session org-babel-lua-buffers)))
+      session)))
+
+(defun org-babel-lua-initiate-session (&optional session params)
+  "Create a session named SESSION according to PARAMS."
+  (unless (string= session "none")
+    (error "Sessions currently not supported, work in progress")
+    (org-babel-lua-session-buffer
+     (org-babel-lua-initiate-session-by-key session))))
+
+(defvar org-babel-lua-eoe-indicator "--eoe"
+  "A string to indicate that evaluation has completed.")
+
+(defvar org-babel-lua-wrapper-method
+  "
+function main()
+%s
+end
+
+fd=io.open(\"%s\", \"w\")
+fd:write( main() )
+fd:close()")
+(defvar org-babel-lua-pp-wrapper-method
+  "
+-- table to string
+function t2s(t, indent)
+   if indent == nil then
+      indent = \"\"
+   end
+   if type(t) == \"table\" then
+      ts = \"\"
+      for k,v in pairs(t) do
+         if type(v) == \"table\" then
+            ts = ts .. indent .. t2s(k,indent .. \"  \") .. \" = \\n\" ..
+               t2s(v, indent .. \"  \")
+         else
+            ts = ts .. indent .. t2s(k,indent .. \"  \") .. \" = \" ..
+               t2s(v, indent .. \"  \") .. \"\\n\"
+         end
+      end
+      return ts
+   else
+      return tostring(t)
+   end
+end
+
+
+function main()
+%s
+end
+
+fd=io.open(\"%s\", \"w\")
+fd:write(t2s(main()))
+fd:close()")
+
+(defun org-babel-lua-evaluate
+  (session body &optional result-type result-params preamble)
+  "Evaluate BODY as Lua code."
+  (if session
+      (org-babel-lua-evaluate-session
+       session body result-type result-params)
+    (org-babel-lua-evaluate-external-process
+     body result-type result-params preamble)))
+
+(defun org-babel-lua-evaluate-external-process
+  (body &optional result-type result-params preamble)
+  "Evaluate BODY in external lua 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."
+  (let ((raw
+         (pcase result-type
+           (`output (org-babel-eval org-babel-lua-command
+                                   (concat (if preamble (concat preamble "\n"))
+                                           body)))
+           (`value (let ((tmp-file (org-babel-temp-file "lua-")))
+                    (org-babel-eval
+                     org-babel-lua-command
+                     (concat
+                      (if preamble (concat preamble "\n") "")
+                      (format
+                       (if (member "pp" result-params)
+                           org-babel-lua-pp-wrapper-method
+                         org-babel-lua-wrapper-method)
+                       (mapconcat
+                        (lambda (line) (format "\t%s" line))
+                        (split-string
+                         (org-remove-indentation
+                          (org-trim body))
+                         "[\r\n]") "\n")
+                       (org-babel-process-file-name tmp-file 'noquote))))
+                    (org-babel-eval-read-file tmp-file))))))
+    (org-babel-result-cond result-params
+      raw
+      (org-babel-lua-table-or-string (org-trim raw)))))
+
+(defun org-babel-lua-evaluate-session
+    (session body &optional result-type result-params)
+  "Pass BODY to the Lua process in SESSION.
+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."
+  (let* ((send-wait (lambda () (comint-send-input nil t) (sleep-for 0 5)))
+        (dump-last-value
+         (lambda
+           (tmp-file pp)
+           (mapc
+            (lambda (statement) (insert statement) (funcall send-wait))
+            (if pp
+                (list
+                 "-- table to string
+function t2s(t, indent)
+   if indent == nil then
+      indent = \"\"
+   end
+   if type(t) == \"table\" then
+      ts = \"\"
+      for k,v in pairs(t) do
+         if type(v) == \"table\" then
+            ts = ts .. indent .. t2s(k,indent .. \"  \") .. \" = \\n\" ..
+               t2s(v, indent .. \"  \")
+         else
+            ts = ts .. indent .. t2s(k,indent .. \"  \") .. \" = \" ..
+               t2s(v, indent .. \"  \") .. \"\\n\"
+         end
+      end
+      return ts
+   else
+      return tostring(t)
+   end
+end
+"
+                 (format "fd:write(_))
+fd:close()"
+                         (org-babel-process-file-name tmp-file 'noquote)))
+              (list (format "fd=io.open(\"%s\", \"w\")
+fd:write( _ )
+fd:close()"
+                            (org-babel-process-file-name tmp-file
+                                                          'noquote)))))))
+        (input-body (lambda (body)
+                      (mapc (lambda (line) (insert line) (funcall send-wait))
+                            (split-string body "[\r\n]"))
+                      (funcall send-wait)))
+         (results
+          (case result-type
+            (output
+             (mapconcat
+              #'org-trim
+              (butlast
+               (org-babel-comint-with-output
+                   (session org-babel-lua-eoe-indicator t body)
+                 (funcall input-body body)
+                 (funcall send-wait) (funcall send-wait)
+                 (insert org-babel-lua-eoe-indicator)
+                 (funcall send-wait))
+               2) "\n"))
+            (value
+             (let ((tmp-file (org-babel-temp-file "lua-")))
+               (org-babel-comint-with-output
+                   (session org-babel-lua-eoe-indicator nil body)
+                 (let ((comint-process-echoes nil))
+                   (funcall input-body body)
+                   (funcall dump-last-value tmp-file
+                            (member "pp" result-params))
+                   (funcall send-wait) (funcall send-wait)
+                   (insert org-babel-lua-eoe-indicator)
+                   (funcall send-wait)))
+               (org-babel-eval-read-file tmp-file))))))
+    (unless (string= (substring org-babel-lua-eoe-indicator 1 -1) results)
+      (org-babel-result-cond result-params
+       results
+        (org-babel-lua-table-or-string results)))))
+
+(defun org-babel-lua-read-string (string)
+  "Strip 's from around Lua string."
+  (if (string-match "^'\\([^\000]+\\)'$" string)
+      (match-string 1 string)
+    string))
+
+(provide 'ob-lua)
+
+
+
+;;; ob-lua.el ends here
diff --git a/testing/lisp/test-ob-lua.el b/testing/lisp/test-ob-lua.el
new file mode 100644
index 0000000..d0c1302
--- /dev/null
+++ b/testing/lisp/test-ob-lua.el
@@ -0,0 +1,141 @@
+;;; test-ob-lua.el --- tests for ob-lua.el
+
+;; Copyright (c) 2016 Thibault Marin
+;; Authors: Thibault Marin
+
+;; This file is not part of GNU Emacs.
+
+;; 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 of the License, 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Code:
+(unless (featurep 'ob-lua)
+  (signal 'missing-test-dependency "Support for Lua code blocks"))
+
+(ert-deftest test-ob-lua/simple-value ()
+  "Test associative array return by value."
+  (should
+   (= 2
+      (org-test-with-temp-text
+         "#+name: eg
+| a   | 1 |
+| b   | 2 |
+
+#+header: :results value
+#+header: :var x = eg
+#+begin_src lua
+return x['b']
+#+end_src"
+        (org-babel-next-src-block)
+        (org-babel-execute-src-block)))))
+
+(ert-deftest test-ob-lua/simple-output ()
+  "Test text output from table."
+  (should
+   (equal "result: c\n"
+         (org-test-with-temp-text
+             "#+name: eg
+| a | b | c | d |
+
+#+header: :results output
+#+header: :var x = eg
+#+begin_src lua
+print('result: ' .. x[1][3])
+#+end_src"
+           (org-babel-next-src-block)
+           (org-babel-execute-src-block)))))
+
+
+(ert-deftest test-ob-lua/colnames-yes-header-argument ()
+  "Test table passing with `colnames' header."
+  (should
+   (equal "a"
+         (org-test-with-temp-text
+             "#+name: eg
+| col |
+|-----|
+| a   |
+| b   |
+
+#+header: :colnames yes
+#+header: :var x = eg
+#+begin_src lua
+return x[1]
+#+end_src"
+           (org-babel-next-src-block)
+           (org-babel-execute-src-block)))))
+
+
+(ert-deftest test-ob-lua/colnames-yes-header-argument-pp ()
+  "Test table passing with `colnames' header and pp option."
+  (should
+   (equal "a = 12\nb = 13\n"
+         (org-test-with-temp-text
+             "#+name: eg
+| col | val |
+|-----+-----|
+| a   |  12 |
+| b   |  13 |
+
+#+header: :results value pp
+#+header: :colnames yes
+#+header: :var x = eg
+#+begin_src lua
+return x
+#+end_src"
+           (org-babel-next-src-block)
+           (org-babel-execute-src-block)))))
+
+(ert-deftest test-ob-lua/colnames-nil-header-argument ()
+  "Test table with `colnames' set to `nil'."
+  (should
+   (equal "1 = a\n2 = b\n"
+         (org-test-with-temp-text
+             "#+name: eg
+| col |
+|-----|
+| a   |
+| b   |
+
+#+header: :colnames nil
+#+header: :var x = eg
+#+header: :results value pp
+#+begin_src lua
+return x
+#+end_src"
+           (org-babel-next-src-block)
+           (org-babel-execute-src-block)))))
+
+(ert-deftest test-ob-lua/colnames-no-header-argument ()
+  "Test table passing without `colnames'."
+  (should
+   (equal "1 = col\n2 = a\n3 = b\n"
+         (org-test-with-temp-text
+             "#+name: eg
+| col |
+|-----|
+| a   |
+| b   |
+
+#+header: :colnames no
+#+header: :var x = eg
+#+header: :results value pp
+#+begin_src lua
+return x
+#+end_src"
+           (org-babel-next-src-block)
+           (org-babel-execute-src-block)))))
+
+(provide 'test-ob-lua)
+
+;;; test-ob-lua.el ends here
-- 
2.8.1

> The changes look fine. Could you send them using git format-patch, with
> a proper commit message? See
> <http://orgmode.org/worg/org-contribute.html#patches> for details.

The attached patch (using git format-patch) is adding test-ob-lua.el and
ob-lua.el.  My contribution to ob-lua.el is only a tiny patch on top of
Dieter's ob-lua.el but it appears as a new file in the patch, since
ob-lua.el is not currently in the repository.

>> By the way, when trying to run the tests from emacs, I had an error
>> message when doing a (require 'org-test): "let: Required feature `ert-x'
>> was not provided".  Am I doing something wrong?  I worked around it by
>> (1) installing the `ertx' package and (2) replacing (require 'ert-x) by
>> (require 'ertx) in org-test.el (that's probably the wrong thing to do,
>> but it allowed me to run my tests).
>
> I usually only call "make test" from Org root directory.

I am still a bit confused about this (make test complains about a
missing dependency for ob-lua, maybe because it is in contrib/lisp?),
but I can run the test using the command line emacs --batch command
described in testing/README, and it does not require any change to
org-test.el, so I'll run tests this way from now on.

> Also, I suggest to move `should' and the test on the outside of the
> sexp, like this

Done, thanks.

Please let me know if some other changes are needed.  Thanks for the
guidance.

thibault