hamacs/ha-programming-scheme.org

#+TITLE:  Programming in Scheme for SICP
#+AUTHOR: Howard X. Abrams
#+DATE:   2022-03-01
#+FILETAGS: :emacs:

A literate programming file configuring Emacs.

#+BEGIN_SRC emacs-lisp :exports none
  ;;; ha-programming-scheme --- Configuration for Scheme. -*- lexical-binding: t; -*-
  ;;
  ;; © 2022 Howard X. Abrams
  ;;   This work is licensed under a Creative Commons Attribution 4.0 International License.
  ;;   See http://creativecommons.org/licenses/by/4.0/
  ;;
  ;; Author: Howard X. Abrams <http://gitlab.com/howardabrams>
  ;; Maintainer: Howard X. Abrams
  ;; Created: March  1, 2022
  ;;
  ;; This file is not part of GNU Emacs.
  ;;
  ;; *NB:* Do not edit this file. Instead, edit the original literate file at:
  ;;            /Users/howard.abrams/other/hamacs/ha-programming-scheme.org
  ;;       And tangle the file to recreate this one.
  ;;
  ;;; Code:
  #+END_SRC
* Introduction
First, install MIT-Scheme, the Lisp dialect used throughout the SICP book:
=brew install mit-scheme= or =sudo apt install mit-scheme= .
#+BEGIN_SRC sh
  brew install mit-scheme
#+END_SRC

Or better yet, let’s use Guile:
#+BEGIN_SRC sh
  brew install guile
#+END_SRC
* Geiser (Scheme Interface)
The [[https://www.nongnu.org/geiser/][geiser project]] attempts to be the interface between Emacs and various Schemes. Since I can’t decide which to use, I’ll install/configure them all.

#+BEGIN_SRC emacs-lisp
  (use-package geiser
    :init
    (setq geiser-mit-binary "/usr/local/bin/scheme"
          geiser-racket-binary "/usr/local/bin/racket"
          geiser-guile-binary "/usr/local/bin/guile"
          geiser-active-implementations '(guile)
          geiser-default-implementations '(guile))
    :config
    (use-package geiser-mit)
    (use-package geiser-guile)
    (use-package geiser-racket)

    (add-to-list 'org-babel-load-languages '(scheme . t)))
#+END_SRC
Do we need a Scheme work for Org Babel? According to [[https://orgmode.org/worg/org-contrib/babel/languages/ob-doc-scheme.html][this document]], we just need to make sure we add the =:session= variable to start the REPL.
** Try it Out
:PROPERTIES:
:header-args:scheme:    :session *scheming* :results value
:END:

This should work?
#+name: hello-world
#+header: :var message="Hello World! What?"
#+begin_src scheme
message
#+end_src

However, it doesn’t output the results /back into/ this buffer. What is the point of connecting it to =ob=?

** Install SICP
:PROPERTIES:
:header-args:scheme: :session sicp :results value replace
:END:
Let’s get the book available as an Info page:
#+BEGIN_SRC emacs-lisp
(use-package sicp)
#+END_SRC

And does this work?
#+BEGIN_SRC scheme
  (inc 42)
#+END_SRC

Still having difficulty getting the Scheme REPL to output the results back into this document. Let’s try Racket...

If we want to read the [[file:~/.emacs.d/straight/build/sicp/sicp.info][sicp.info]] file, looks like we need this, at least, temporarily:
#+BEGIN_SRC emacs-lisp
(add-to-list 'auto-mode-alist '("\\.info\\'" . Info-mode))
#+END_SRC
* Racket
Actually, let’s do this with [[https://racket-lang.org/][Racket]]:
#+BEGIN_SRC emacs-lisp
  brew install racket
#+END_SRC

While Racket, as a Scheme, should work with Geiser (below), let’s also get [[https://racket-mode.com/][racket-mode]] working:
#+BEGIN_SRC emacs-lisp
  (use-package racket-mode
    :config (setq racket-program "/usr/local/bin/racket"))
#+END_SRC

Can we get Racket working with Org?
#+BEGIN_SRC emacs-lisp
  (use-package ob-racket
    :straight (:type git :protocol ssh :host github :repo "DEADB17/ob-racket")
    :after org
    :config
    (add-to-list 'org-babel-load-languages '(racket . t)))
#+END_SRC

** Try It Out
:PROPERTIES:
:header-args:racket: :session racketeering :results value replace :lang racket
:END:
Working for values?
#+BEGIN_SRC racket
  (* 6 7)
#+END_SRC

#+RESULTS:
: 42

Working for output?
#+BEGIN_SRC racket :results output replace
  (define str-1 "hello")
  (define str-2 "world")
  (define all (string-join (list str-1 str-2) ", "))
  (display (string-titlecase all))
#+END_SRC

#+RESULTS:
: Hello, World

The interface is horrendously slow, as the =:session= doesn’t seem to work, and starting up a Racket REPL takes a long time.

** SICP and Racket
:PROPERTIES:
:header-args:racket: :session *rsicp* :results value replace :lang sicp
:END:
If using [[https://docs.racket-lang.org/sicp-manual/SICP_Language.html][Racket for SICP]], install the SICP language:
#+BEGIN_SRC sh
  raco pkg install --auto --update-deps sicp
#+END_SRC

We now can give it a =#lang sicp= (or better yet, use the =:lang= header) to define certain SICP-specify features:

Let’s try this now:
#+BEGIN_SRC racket
(inc 42)
#+END_SRC

#+RESULTS:
: 43

* Technical Artifacts                                :noexport:
Let's =provide= a name so we can =require= this file:

#+BEGIN_SRC emacs-lisp :exports none
  (provide 'ha-programming-scheme)
  ;;; ha-programming-scheme.el ends here
  #+END_SRC

#+DESCRIPTION: A literate programming file configuring Emacs.

#+PROPERTY:    header-args:sh :tangle no
#+PROPERTY:    header-args:emacs-lisp  :tangle yes
#+PROPERTY:    header-args    :results none :eval no-export :comments no mkdirp yes

#+OPTIONS:     num:nil toc:nil todo:nil tasks:nil tags:nil date:nil
#+OPTIONS:     skip:nil author:nil email:nil creator:nil timestamp:nil
#+INFOJS_OPT:  view:nil toc:nil ltoc:t mouse:underline buttons:0 path:http://orgmode.org/org-info.js