ob-clojure-literate

Screenshots

use default session

#+begin_src clojure :session "*cider-repl ob-clojure*" :results output
(prn *ns*)
#+end_src

#+RESULTS:
: #namespace[user]

support generate plot

support header argument :dir

Installation

use-package

(use-package ob-clojure-literate
  :ensure t
  :after org
  :init
  (setq ob-clojure-literate-auto-jackin-p t)
  (add-hook 'org-mode-hook #'ob-clojure-literate-mode)
  )

Motivation

I like Emacs Org-mode “Literate Programming” very much. It’s a kind of paradigm. I can apply this idea on many places. Now Clojure is my favourite programming language. I hope to combine them together. But ob-clojure does not suitable for Literate Programming very much like other language babel (like Python) supports.

This README is totally written in Org-mode Literate Programming.

So I decide to solve this problem in my way.

Todos

Support generate inline plot image under current working directory

State “TODO” from [2017-12-22 Fri 09:52]

Support babel header argument :dir

State “TODO” from [2017-12-22 Fri 09:52]

Usage

This package workflow

auto start an CIDER REPL for ob-clojure

First, create a plain Clojure project with Leiningen to used for ob-clojure.
```
lein new ob-clojure
    
```

Then auto start CIDER REPL session in this plain Clojure project.

Set ob-clojure default header arguments to a static session name:

(add-to-list 'org-babel-default-header-args:clojure
             '(:session . "*cider-repl ob-clojure*"))

open a file in project to prepare for CIDER jack-in.

(progn
  (find-file (expand-file-name "~/.emacs.d/Org-mode/ob-clojure/src/ob_clojure/core.clj"))
  (cider-jack-in))

To fix org-babel-execute:clojure has a line (cider-current-ns) which will invoke (cider-find-ns). The (cider-find-ns) will try to extract Clojure namespace from current buffer.
This will cause a problem, like in following org-mode file content:
```
* test results output

#+BEGIN_SRC clojure :result output
(println "hi")
(println (str *ns*))
#+END_SRC

When I execute first src block [C-c C-c], it will find namespace and
return wrong namespace ~kk~ in second src block. This is not a
expected behavior.

* different namespace

#+BEGIN_SRC clojure :result output
(in-ns 'kk)
(println (str *ns*))
#+END_SRC
    
```
In order to fix this problem, I asked a lot of places, and try many methods.

Finally I found the variable cider-buffer-ns (which in function cider-current-ns) docstring description.
```
Current Clojure namespace of some buffer.

Useful for special buffers (e.g. REPL, doc buffers) that have to
keep track of a namespace.

This should never be set in Clojure buffers, as there the namespace
should be extracted from the buffer's ns form.
    
```
Then I come up an idea:
- should I include org-mode as special for CIDER cider-buffer-ns?
  - It is nil in Clojure buffer.
  - It is ”user” in cider-repl ob-clojure session.
  - Maybe I should use elisp code to manually set this ns to user.

So the final solution source code is:

;; auto start CIDER REPL session in a complete Leiningen project environment for Org-mode Babel by jack-in.
(add-to-list 'org-babel-default-header-args:clojure
             '(:session . "*cider-repl ob-clojure*"))

(progn
  (find-file (expand-file-name "~/.emacs.d/Org-mode/ob-clojure/src/ob_clojure/core.clj"))
  (cider-jack-in))

(defun ob-clojure-cider-do-not-find-ns ()
  "Fix the issue that `cider-current-ns' try to invoke `clojure-find-ns' to extract ns from buffer."
  (setq-local cider-buffer-ns "user"))
(add-hook 'org-mode-hook #'ob-clojure-cider-do-not-find-ns)

But the function ob-clojure-cider-don-not-find-ns can be smarter:

How to execute elisp code in a specific buffer without actually switching to it? I can writing a function get a buffer local variable in a specific (regex matched) buffer.

(defun ob-clojure-cider-do-not-find-ns ()
  "Fix the issue that `cider-current-ns' try to invoke `clojure-find-ns' to extract ns from buffer."
  (with-current-buffer "*cider-repl ob-clojure*"
    (defvar ob-clojure-cider-repl-ns cider-buffer-ns)
    (setq-local cider-buffer-ns ob-clojure-cider-repl-ns)))

bbatsov/ob-clojure-literate