daviderestivo

Reader Macros in Common Lisp

This post also appears on lisper.in.

Reader macros are perhaps not as famous as ordinary macros. While macros are a great way to create your own DSL, reader macros provide even greater flexibility by allowing you to create entirely new syntax on top of Lisp.

Paul Graham explains them very well in [On Lisp][] (Chapter 17, Read-Macros):

The three big moments in a Lisp expression's life are read-time, compile-time, and runtime. Functions are in control at runtime. Macros give us a chance to perform transformations on programs at compile-time. ...read-macros... do their work at read-time.

daviderestivo

# Useful for improving Time Machine backup prep. times, Mac App Store install speeds, etc.
sudo sysctl debug.lowpri_throttle_enabled=0

# To restore defaults
sudo sysctl debug.lowpri_throttle_enabled=1

daviderestivo

steps

1. connect kobo to your device
2. open a file browser
3. navigate to the hidden folder .kobo/Kobo
4. open the file Kobo eReader.conf
5. navigate to the section [FeatureSettings]
6. add the line ExportHighlights=true and save
7. disconnect the device
8. now you can long press on a book and export the note file into a .txt file which will be saved alongside your books. to get it connect your ereader.

daviderestivo

;;;; **deep binding**


;;; look up
(cdr (assq 'the-symbol *the-stack*))


;;; funcall
; wind...
(loop for arg  in args

daviderestivo

(defun helm-search-doc-ag ()
  "Search for a keyword in the Documents folder using ag"
  (interactive)
      (helm-do-ag "~/Documents"))

(global-set-key (kbd "<f5>") 'helm-search-doc-ag)

daviderestivo

  ;; Expand "unpushed to upstream or recent" magit section
  (push (cons [unpushed status] 'show) magit-section-initial-visibility-alist)

daviderestivo

;; Unset var1
(setq var1 nil)

;; Create a mutex and an associated conditional variable
(setq mut1 (make-mutex "mut1"))
(setq cond-var1 (make-condition-variable mut1 "cond-var1"))

;; Read and set functions used by r1 and s1 threads
(defun read-global-var1 ()
  (with-mutex mut1

daviderestivo

(defun galactic-emacs-eshell-prompt ()
  "Customize eshell prompt.

This function requires `all-the-icons' package to be installed
(https://github.com/domtronn/all-the-icons.el)."
  (if (display-graphic-p)
      (setq galactic-emacs-header-bg "#282C34")
    ;; The background used when Emacs runs in a terminal
    (setq galactic-emacs-header-bg "black"))
  ;; In order to set the eshell prompt correctly we need to

daviderestivo

```
cd /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/Formula
git log --oneline imagemagick@6.rb

7fbfe5b80 imagemagick@6: update 6.9.9-15 bottle.
e350b9b9b imagemagick@6 6.9.9-15
1b98748c9 imagemagick@6: update 6.9.9-14 bottle.
3075a3186 imagemagick@6: update 6.9.9-14 bottle.
c52c493a1 imagemagick@6 6.9.9-14
a03627c39 imagemagick@6: update 6.9.9-12 bottle.

daviderestivo

(defun drestivo/org-download-method (link)
  "This is an helper function for org-download.
It creates an \"./image\" folder within the same directory of the org file.
Images are separated inside that image folder by additional folders one per
org file.
More info can be found here: https://github.com/abo-abo/org-download/issues/40.
See the commit message for an example:
https://github.com/abo-abo/org-download/commit/137c3d2aa083283a3fc853f9ecbbc03039bf397b"
  (let ((filename
         (file-name-nondirectory