Docs for Racket + emacs

I have been doing all my research prototyping in the "programming language programming language" Racket. For those of you who work in emacs rather than DrRacket, you might find it fairly frustrating to move from emacs to the browser to search on docs.racket-lang.org, or if you're savvy, go to the terminal and use raco doc.
I came up with a script that will take whatever symbol your cursor is currently in to the documentation for it, if any. It requires a function from paredit, but you should have that loaded with scheme/racket files already.

(setq raco-location "raco")
(require 'paredit)

(setq raco-doc-history nil)
(defun call-raco-doc (text)
  (shell-command (concat raco-location " doc -- '" text "' &")))

(defun get-current-word ()
  (paredit-handle-sexp-errors
   (save-excursion
    (progn (backward-sexp)
           (mark-sexp)
           (buffer-substring (mark) (point))))
    (save-excursion
      (progn (mark-sexp)
             (buffer-substring (mark) (point))))))
(defun raco-doc ()
  "call raco doc on selected text"
  (interactive)
  (call-raco-doc (get-current-word)))
(defun raco-doc-prompt ()
  "call raco doc on prompted text"
  (interactive)
  (let ((text (read-string (if (consp raco-doc-history)
                               (concat "raco doc [" (car raco-doc-history) "]: ")
                               "raco doc: ")
                           nil
                           'raco-doc-history
                           ;; default value should be most recent history item
                           (if (consp raco-doc-history)
                               (car raco-doc-history)
                               nil)
                           t))) ;; inherit the current input method
    (call-raco-doc text)))
(defun enable-raco-doc ()
  (define-key scheme-mode-map (kbd "C-c C-r") 'raco-doc)
  (define-key scheme-mode-map (kbd "C-c C-M-r") 'raco-doc-prompt))
(provide 'raco-doc)

Play all mp3s in subtrees

~/bin/playall:

#!/bin/bash
find . -iname '*.mp3' | sort | awk '{ print "\""$0"\"" }' | xargs mplayer

Good for playing all albums of an artist.

But wait! This doesn't give mplayer focus, so you can't press spacebar to pause/unpause. That's extremely annoying. We can fix that by replacing mplayer with mplayer_wrapper:

#!/bin/bash
mplayer "$@" < /dev/tty