Added Elisp code, updated README

README.org

@@ -1,11 +1,27 @@
 [[file:https://cdn.rawgit.com/syl20bnr/spacemacs/442d025779da2f62fc86c2082703697714db6514/assets/spacemacs-badge.svg]]
 
-* Features Tree
+* Table of content :TOC_5_gh:noexport:
+- [[#tree-to-dot][Tree to dot]]
+  - [[#presentation][Presentation]]
+  - [[#usage][Usage]]
+    - [[#tldr][TL;DR]]
+      - [[#elisp][Elisp]]
+      - [[#scheme][Scheme]]
+    - [[#more-details][More details]]
+      - [[#elisp-1][Elisp]]
+      - [[#scheme-1][Scheme]]
+    - [[#my-elements-are-not-alignedcentered-what-do][My elements are not aligned/centered, what do?]]
+    - [[#how-can-i-do-that-on-windows][How can I do that on Windows?]]
+      - [[#scheme-2][Scheme]]
+      - [[#elisp-2][Elisp]]
+- [[#license][License]]
+
+* Tree to dot
 
 ** Presentation
 
- *Features Tree*  is a small  utility for linguists and  especially conlangers
-   that allows  them to declare  trees with any number  of children per  node. I
+ *Tree to dot* is a small utility for linguists and especially conlangers that
+   allows  them  to declare  trees  with  any number  of  children  per node.  I
    especially made it with the option  in mind to make feature contrastive trees
    as presentented by  Joseph Windsor in his talk during  the /Language Creation
    Conference 8/, with examples below.
@@ -18,8 +34,16 @@
 
 *** TL;DR
 
-    In your *NIX terminal, clone the project, edit the example trees or create a
-    new one, and execute this:
+**** Elisp
+
+     Load this source code within Emacs, either in a ~emacs-lisp-mode~ buffer or
+     in a  source block in  your ~org-mode~ buffer.  Create trees, pass  them as
+     arguments to ~tree-to-dot~, execute, and voilà.
+
+**** Scheme
+
+     In your *NIX terminal, clone the  project, edit the example trees or create
+     a new one, and execute this:
      #+BEGIN_SRC sh
        cd features-tree
        chicken-csc features-tree.scm             # Compile the .scm file
@@ -29,6 +53,49 @@
 
 *** More details
 
+**** Elisp
+
+     The Elisp code was  written with the intent of being  used from org-mode in
+     order to create inline  images out of code. Put that source  code in a code
+     block in org-mode, and declare it as a noweb block.
+     #+BEGIN_SRC org
+       ,#+NAME: process-tree
+       ,#+BEGIN_SRC emacs-lisp :exports none :noweb yes
+         Code here!
+       ,#+END_SRC
+     #+END_SRC
+     Don’t forget to name your source blocks, it will be important for the noweb
+     part later.
+
+     Then, you  can declare later a  beautiful tree in another  code block, like
+     so, and call your ~tree-to-dot~ function on it:
+     #+BEGIN_SRC org
+       ,#+NAME: my-tree
+       ,#+BEGIN_SRC emacs-lisp :noweb yes :exports none
+         (defvar mytree
+           '("Tree"
+             ("First child"
+              ("First child’s child"))
+             ("Second child"
+              ("Second child’s first child")
+              ("Second child’s second child"))))
+       ,#+END_SRC
+     #+END_SRC
+
+     You can now finally create one last code block in order to get your image:
+     #+BEGIN_SRC org
+       ,#+BEGIN_SRC dot :file whatever.png :var input=my-tree :exports results
+         $input
+       ,#+END_SRC
+     #+END_SRC
+     You can now export this last code block  only to get your image. It will be
+     automatically evaluated when  you export your org buffer, but  you can also
+     manually trigger  the evaluation by  typing ~C-c  C-c~ with your  cursor on
+     this last code block. Be sure to have enabled the dot language in babel and
+     to have configured it properly ([[https://www.orgmode.org/worg/org-contrib/babel/languages/ob-doc-dot.html][this]] might help).
+
+**** Scheme
+
      For now,  the workflow is not  the best, as  you have to edit  yourself the
      source code and re-compile it each time you edit your own tree.
 
@@ -37,10 +104,10 @@
      #+BEGIN_SRC scheme
        ("text" (child1) (child2) ...)
      #+END_SRC
-    Each child is itself a tree that should follow the same type of declaration,
-    with as many child as you like per  node –I discourage you to have more than
-    nine children  though, otherwise it might  break the output. If  a node does
-    not have any child, it should be declared like so:
+     Each  child  is  itself  a  tree  that  should  follow  the  same  type  of
+     declaration, with as many  child as you like per node  –I discourage you to
+     have more than  nine children though, otherwise it might  break the output.
+     If a node does not have any child, it should be declared like so:
      #+BEGIN_SRC scheme
        ("text")
      #+END_SRC
@@ -90,19 +157,18 @@
 
      Once you’ve declared the tree you want  to get, modify the last line of the
      source code =(tree-to-dot ...)= by  replacing the default argument with the
-    name   of   your   tree.    For   the   first   example,   we   would   call
- =(tree-to-dot vowels)=,  while    for   the    second   we    would     call
- =(tree-to-dot syntax-tree)=.
+     name  of your  tree. For  the first  example, we  would call  =(tree-to-dot
+     vowels)=, while for the second we would call =(tree-to-dot syntax-tree)=.
 
      *Only one =(tree-to-dot)= call can be done at once, else what follows might
      break!*
 
      Once you’ve  done that, compile your  file! I personally use  [[https://call-cc.org/][Chicken]] as my
-    Scheme compiler, but if you already have another, you can use your own. Just
-    replace my calls  to =chicken-csc= by your own compiler’s  command. Also, be
-    aware that I use =chicken-csc= as  the command for che Chicken compiler, but
-    if you also  use Chicken, you might  have to call =csc=  instead (this might
-    mean you have an older version than the one I use).
+     Scheme compiler,  but if you  already have another,  you can use  your own.
+     Just  replace my  calls to =chicken-csc= by  your own  compiler’s command.
+     Also, be  aware that  I use =chicken-csc= as the  command for  che Chicken
+     compiler, but if you also use Chicken, you might have to call =csc= instead
+     (this might mean you have an older version than the one I use).
 
      Now that you’ve  compiled your file, you  will have to execute  it. If your
      edits were alright, you should have  some text output that looks like this,
@@ -160,10 +226,10 @@
      #+END_SRC
      If you get some errors, then you fucked up somewhere in your tree, probably
      missing some  parenthesis or  you forgot  to add the ='= before  the first
-    parenthesis after the name of your tree. Go back to your source file and fix
-    that. Also, it  might be easier to edit  the file if you have  a decent text
-    editor, I’d  recommend using something along  the lines of VS  Code, Atom or
-    Brackets,  or even  Emacs if  you  are not  afraid by  steep –but  extremely
+     parenthesis after the  name of your tree.  Go back to your  source file and
+     fix that. Also,  it might be easier to  edit the file if you  have a decent
+     text editor, I’d recommend using something along the lines of VS Code, Atom
+     or Brackets, or  even Emacs if you  are not afraid by  steep –but extremely
      rewarding– learning curves.
 
      Now, you need to have [[https://graphviz.org/][Graphviz]]’s  dot tool installed to generate images. In
@@ -184,11 +250,18 @@
 
 *** How can I do that on Windows?
 
+**** Scheme
+
      IDK. Get a UNIX terminal (like the Linux subsystem, Putty(?) or Cygwin) and
      apply what has  been said before, maybe. If you  have a better explanation,
      you are  more than welcome  to either send  it with a  new issue or  a pull
      request.
 
+**** Elisp
+
+     This should work properly with Emacs on Windows, provided you’ve configured
+     properly org-babel. I haven’t tested it though.
+
 * License
 
   Check out the [[file:LICENSE.org]]. TL;DR: a  GPLv3 licence gives you the right to

tree-to-dot.el

@@ -0,0 +1,50 @@
+(defun declare-node (node-text node-generation)
+  "Declares a node in the graphviz source code. The node’s identifier will be
+~node-generation~, and it will bear the label ~node-text~."
+  (concat (number-to-string node-generation)
+          "[label=\""
+          node-text
+          "\"];"))
+
+(defun make-link (previous-node current-node)
+  "This creates a link in the graphviz source code between the two nodes
+bearing ~previous-node~ and ~current-node~ respectively as their node
+identifier."
+  (concat (number-to-string previous-node) " -- "
+          (number-to-string current-node) ";"))
+
+(defun tree-to-dot-helper (tree current-generation previous-generation)
+  "Helper to ~tree-to-dot~ that translates an Elisp tree with any number of
+children per node to a corresponding graphviz file that can be executed from
+dot.
+Arguments:
+- tree :: tree-to-convert
+- current-generation :: Generation number, incremented when changing from a node
+     to another node from the same generation, multiplied by 10 when going from
+     a node to one of its children.
+- previous-generation :: generation number from previous named node"
+  (cond
+   ((null tree) "")
+   ((atom (car tree)) ;; '("text" () () ())
+    (concat (declare-node (car tree) current-generation)
+            (make-link previous-generation current-generation)
+            (tree-to-dot-helper (cdr tree)
+                                (+ 1 (* 10 current-generation))
+                                current-generation)))
+   ((listp (car tree)) ;; '(() () ())
+    (concat (tree-to-dot-helper (car tree) ;; child of current node
+                                current-generation
+                                previous-generation)
+            (tree-to-dot-helper (cdr tree)
+                                (+ 1 current-generation)
+                                previous-generation)))))
+
+(defun tree-to-dot (tree)
+  "Returns a graphviz’s dot compatible string representing an Elisp tree"
+  (interactive)
+  (if (null tree) ""
+    (concat
+     "graph{node[shape=plaintext];graph[bgcolor=\"transparent\"];"
+     (declare-node (car tree) 0)
+     (tree-to-dot-helper (cdr tree) 1 0)
+     "}")))