Category Archives: Common Lisp

There is nothing cooler than a macr- Err… Mixin?

Posted by Kajtek on

One of the most distinctive features of Common Lisp and Lisp in general, are its code-generation and code-manipulation capabilities.

Probably the best example is the LOOP macro – a Swiss Army knife of iteration that can do pretty much anything. The following snippet iterates a list of random numbers collecting some statistics of its contents and does that while being very concise and readable: 

(let ((random (loop with max = 500
                    for i from 0 to max
                    collect (random max))))
  (loop for i in random
          counting (evenp i) into evens
          counting (oddp i) into odds
          summing i into total
          maximizing i into max
          minimizing i into min
        finally (format t "Stats: ~A"
                          (list min max total evens odds))))

Stats: (0 499 120808 261 240)

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Instant docs in StumpWM

Posted by Kajtek on

Here’s a cool hack I use to optimize my docs searching.

Let’s start off with DuckDuckGo search engine.
By itself it’s a pretty powerful tool thanks to its numerous features like the !bang syntax. For example searching for: 

!cpp std::string::clear

…takes me exactly where I want.

Let’s use it to our advantage, shall we?

StumpWM is a tailing window manager that allows you to define system-wide key bindings that work and feel pretty much like Emacs ones. Combining that with DuckDuckGo’es !bang syntax makes you just a few clicks away from anything out there: 

(defcommand duckduckgo (phrase) ((:string "Search: "))
  "Searches for something on DuckDuckGo."
  (run-shell-command
    (concatenate 'string
                 *your-fav-webbrowser*
                 " http://duckduckgo.com/?q="
                 (substitute #\+ #\Space phrase))))
(define-key *root-map* (kbd "d") "duckduckgo")

Now, if you want to find out if I used substitute correctly all you have to do is: 

C-t d !lisp substitute

…what will take you directly there. Turns out I did.

But wait, there’s more!
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